# Regulatory Oversight Report for Uranium Mines, Mills, Historic and Decommissioned Sites in Canada: 2017

## Clear Language Summary

The Regulatory Oversight Report for Uranium Mines, Mills, Historic and Decommissioned Sites in Canada: 2017 provides information about the CNSC’s work to ensure the safety and protection of people and the environment around uranium mines and mills across Canada, particularly in Saskatchewan. The 2017 report also includes a summary of the CNSC’s work to demonstrate that historic and decommissioned mines in Canada remain safe and pose no risk to the health and safety of the environment or people.

### Uranium mines and mills – Saskatchewan

Overall, the uranium mines and mills in Saskatchewan continued to operate safely in 2017, and there were no releases that could have harmed human health or the environment. The country foods and water surrounding these sites remains safe for consumption.

The following uranium mines and mills in Saskatchewan are covered in the 2017 report:

• Cigar Lake – operating uranium mine
• McArthur River – operating uranium mine
• Rabbit Lake – shut-down uranium mine and mill
• Key Lake – operating uranium mill
• McClean Lake – operating uranium mill
• Cluff Lake – decommissioned uranium mine and mill
• Beaverlodge – decommissioned historic uranium mine and mill
• Gunnar – decommissioned historic uranium mine, which is undergoing active remediation
• Lorado – decommissioned historic uranium mine, which is undergoing active remediation

During 2017, the operations at all of these sites remained safe. In summary:

• Workers at each site were safe and properly protected.
• There were no releases that could have harmed the environment or health and safety of people.
• All of the water released from the site was safe.
• Airborne radiation was not increased as a result of these sites.
• Fish and plants were safe to eat.
• There were no events that affected the environment or the people nearby.

### Uranium mines and mills – Northwest Territories

The following decommissioned historic uranium mines and mills in the Northwest Territories are covered in the 2017 report:

• Rayrock
• Port Radium

Work is continuing at these sites to ensure that they remain safe and there is proper protection of the environment and the health and safety of people.

There were no releases from these sites in 2017 and there were no events that could have harmed people or the environment. Country foods and water around these sites remains safe for consumption.

### Uranium mines and mills – Ontario

The following uranium mine and mill sites in Ontario are covered in the 2017 report:

• Deloro – decommissioned historic uranium mine, which is undergoing active remediation
• Madawaska – decomissioned historic uranium mine, which is undergoing active remediation
• Agnew Lake – decommissioned uranium mine
• Bicroft – decommissioned uranium mine
• Dyno – decommissioned uranium mine
• Elliot Lake – decommissioned uranium mines
• Denison and Stanrock – decommissioned uranium mines

All of these Ontario sites were in operating many years ago and have been closed down. Work continues on these sites to protect the environment and the health and safety of people.

There were no releases from these sites in 2017 and there were no events that could have harmed people or the environment. Country foods and water around these sites remain safe for consumption.

### The work of the CNSC

For 2017, CNSC staff confirmed that these sites remained safe and did not harm people or the environment by:

• conducting regular onsite inspections of all sites, including measuring radiation levels and releases to the environment
• reviewing information provided by the licensee, confirming that the sites are operated safely
• conducting independent monitoring of food and water at some sites, to demonstrate that the environment and people are protected
• reporting this information to the public

More information can be found in the Regulatory Oversight Report for Uranium Mines, Mills, Historic and Decommissioned Sites in Canada: 2017.

## Executive Summary

The Regulatory Oversight Report for Uranium Mines, Mills, and Historic and Decommissioned Sites in Canada: 2017 presents Canadian Nuclear Safety Commission (CNSC) staff’s assessment of licensee performance for operating, historic and decommissioned uranium mines and mills regulated by the CNSC. Information provided covers the 2017 calendar year for operating uranium mines and mills and the 2016 and 2017 calendar years for historic and decommissioned sites. This report also provides an update on staff activities related to public information, community engagement, and relevant aspects of the CNSC’s Independent Environmental Monitoring Program. Where possible, trends are shown and information is compared to previous years.

CNSC staff use the safety and control area framework, which contains 14 safety and control areas (SCAs) to evaluate the performance of each licensee. This report provides performance ratings for all 14 SCAs for operating uranium mines and mills and, where applicable, for historic and decommissioned uranium mines and mills. This report focuses on three SCAs that contain the majority of the key performance indicators for these facilities: radiation protection, environmental protection, and conventional health and safety.

The SCA ratings in this report were derived from results of compliance activities conducted by CNSC staff. These activities included onsite inspections, technical assessments, review of reports submitted by licensees, event and incident reviews, and ongoing exchanges of information with licensees.

For the 2017 reporting year, CNSC staff rated all SCAs “satisfactory” for all operating uranium mines and mills – with the exception of the McClean Lake radiation protection SCA, which was rated “fully satisfactory”.

For the 2016 reporting year, CNSC staff rated all SCAs “satisfactory” for all historic and decommissioned sites – with the exception of the radiation protection SCA for Rayrock, Port Radium and Agnew Lake, which were rated as “below expectations”. CNSC staff determined that while these three sites had specific elements of a radiation protection program (such as dosimetry, signage and limited access) the licensees’ radiation protection programs were not comprehensive or well structured.

For the 2017 reporting year, all SCAs for historic and decommissioned sites were rated “satisfactory” with the exception of the Elliot Lake, which was rated “below expectations” for the environmental protection SCA. Nonetheless, CNSC staff have confirmed that safety to persons and the environment was not compromised at these sites.

CNSC staff confirmed that all operating uranium mine and mill sites in Canada operated safely during 2017, and that historic and decommissioned uranium mine and mill sites operated safely through 2016 and 2017.

CNSC staff also concluded that the licensees for the regulated sites covered in this report have made adequate provision for the health and safety of workers, the protection of the public and the environment, and Canada’s international obligations. Documents referenced in this report are available to the public upon request.

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## 1. Introduction

### 1.1 Background

The Canadian Nuclear Safety Commission (CNSC) regulates Canada’s operating, historic and decommissioned uranium mines and mills to protect health, safety, security and the environment; to implement Canada’s international commitments on the peaceful use of nuclear energy; and to disseminate objective scientific, technical and regulatory information to the public. This mandate is derived from the Nuclear Safety and Control Act (NSCA), which, along with the regulations made under it, contains requirements with which CNSC licensees must comply.

Each year, the CNSC produces a regulatory oversight report on the operating performance of Canada’s uranium mines and mills licensees and licensed facilities. Every second year, this report also provides updates on historic and decommissioned uranium mine and mill sites. This report includes data for the 2017 calendar year for operating uranium mines and mills, and data for the 2016 and 2017 calendar years for historic and decommissioned sites.

The report:

• describes the CNSC’s regulatory efforts, public information and community engagement activities, and Independent Environmental Monitoring Program
• includes information on licensee operations, licence changes and major developments at licensed facilities and sites, as well as any significant events
• presents the performance rating for each safety and control area (SCA) for operating, historic and decommissioned uranium mine and mill facilities regulated by the CNSC
• presents performance data on the SCAs of radiation protection, environmental protection, and conventional health and safety for each licensed facility

This report summarizes CNSC staff’s assessment of the following regulated uranium mine and mill facilities:

• Operating facilities
• Cigar Lake
• McArthur River
• Rabbit Lake
• Key Lake
• McClean Lake
• Decommissioned historic sites that are undergoing active remediation
• Gunnar
• Lorado
• Deloro
• Madawaska
• Decommissioned sites
• Beaverlodge
• Cluff Lake
• Rayrock
• Port Radium
• Agnew Lake
• Bicroft
• Dyno
• Elliot Lake
• Denison and Stanrock

Throughout the review period, the CNSC continued to perform compliance activities – including inspections and reviews of licensee submissions and events –for all operating, historic and decommissioned uranium mine and mill sites.

### 1.2 CNSC regulatory efforts

#### 1.2.1 Licensing

The CNSC regulates each uranium mine, mill, historic, and decommissioned site under a separate licence. Appendix A presents the licensing information for the operating, historic and decommissioned sites that are discussed in this report.

An approved licence under the NSCA defines licence terms, licensed activities and licence conditions. Where referred to in the licence, an accompanying licence conditions handbook (LCH) contains compliance verification criteria used by CNSC staff to ensure compliance with the conditions comprising the licence. In some cases, LCHs for historic and decommissioned sites were being developed at the time of this report. Any changes made to the LCHs during this review period are provided in appendix A.

Following a public hearing held on June 7 and 8, 2017, the operating licence for McClean Lake was renewed by the Commission. This is discussed in detail in section 7. In 2017, the Deloro and Rayrock licences were both renewed through a designated officer decision. This is discussed in detail in sections 11 and 15, respectively.

#### 1.2.2 Compliance

The CNSC ensures licensee compliance through verification, enforcement and reporting activities. CNSC staff develop compliance plans for each facility, commensurate with the associated risk, and implement these plans by conducting regulatory activities, including onsite inspections and technical assessments of licensee programs, processes and reports. Changes to compliance plans are made on an ongoing basis in response to events, facility modifications and changes in licensee performance.

Tables 1.1 and 1.2 present data on CNSC staff inspections conducted at operating, historic and decommissioned uranium mine and mills in 2017. Enforcement actions arising from these inspections were provided to the licensees in detailed inspection reports and recorded in the CNSC Regulatory Information Bank, in order to ensure these actions were tracked to completion. CNSC staff verified that licensees have complied with the conditions of enforcement actions and that all actions have been closed.

Table 1.1: Compliance inspections at operating uranium mines and mills
Year Inspections Instances of non-compliance
2017 30 23
Table 1.2: Compliance inspections at historic and decommissioned sites
Year Inspections Instances of non-compliance
2016 18 10
2017 12 12

All instances of non-compliance that were identified at operating, historic and decommissioned sites were of low safety significance. Additional details on the inspections covered in this reporting period can be found in appendix B. CNSC staff assessed licensees’ corrective actions taken in response to identified instances of non-compliance, and verified that the actions were appropriate and acceptable. All enforcement actions were addressed appropriately by licensees and have been closed by CNSC staff.

Other regulatory bodies that conduct inspections at the operating facilities include the Saskatchewan Ministry of Environment, the Saskatchewan Ministry of Labour Relations and Workplace Safety, the Ontario Ministry of Environment and Climate Change, the Ontario Ministry of Labour, and Environment and Climate Change Canada. These regulatory bodies focus primarily on areas of conventional health and safety and environmental protection. CNSC staff take into account the findings from these regulatory bodies when assessing licensees’ performance. When logistically reasonable, joint inspections are conducted with other federal, provincial or territorial regulatory agencies.

#### 1.2.3 Safety and Control Area Framework

SCAs are the technical topics that CNSC staff use across all regulated facilities and activities to assess, evaluate, review, verify and report on regulatory requirements and performance. The CNSC’s SCA Framework, which staff use to evaluate licensee safety performance, includes 14 SCAs. Each SCA is subdivided into specific areas that define its key components. Appendix C provides definitions of SCAs and their specific areas.

CNSC staff use the following four ratings to grade licensee performance in each applicable SCA

• fully satisfactory (FS)
• satisfactory (SA)
• below expectations (BE)
• unacceptable (UA)

Appendix D provides descriptions of these performance ratings.

This report provides CNSC staff’s performance ratings for all applicable SCAs, with a focus on the three SCAs that cover many of the key performance indicators for these operations: radiation protection, environmental protection, and conventional health and safety.

For 2016, historic and decommissioned sites were rated “satisfactory” in most SCAs. The exception was the radiation protection SCA, which was rated “below expectations” for Rayrock, Port Radium, and Agnew Lake mines. Although this SCA was rated “below expectations” for these three sites, CNSC staff determined that this was of low risk due to the nature of the site activities and existing mitigation measures in place. Additional information is provided in sections 15 to 17 of this report.

For 2017, all historic and decommissioned sites were rated “satisfactory” in most SCAs, with the exception of Elliot Lake, which was rated “below expectations” in environmental protection. Additional information is provided in section 20 of this report.

For 2017, all SCA performance ratings for operating uranium mines and mills were rated “satisfactory”, with the exception of radiation protection at McClean Lake which was rated “fully satisfactory”. Additional information related to radiation protection at the McClean Lake Operation is provided in section 7.2 of this report.

CNSC staff concluded, based on the results from regulatory oversight activities, that uranium mine and mill facilities met the following requirements:

• Radiation protection measures were effective, and radiation doses received by workers remained as low as reasonably achievable (ALARA):
• no worker doses in excess of regulatory effective dose limits
• no reported exceedances of action levels
• Environmental protection programs were effective and resulted in emissions and effluents remaining ALARA. Emissions and effluent management across all uranium mines and mills resulted in:
• one exceedance of the discharge limits outlined in the Metal Mining Effluent Regulations
• no exceedances of provincial limits
• Conventional health and safety programs continued to protect workers:
• one reported lost-time injury

Appendix E contains the SCA performance ratings from 2013 to 2017 for operating uranium mines and mills, and the SCA performance rating s from 2015 to 2017 for historic and decommissioned sites.

#### 1.2.4 Independent environmental monitoring program

Under the NSCA, the CNSC requires each nuclear facility licensee to develop, implement and maintain an environmental monitoring program to demonstrate that the public and the environment are protected from releases to the environment related to the facility’s nuclear activities. The results of these monitoring programs are submitted to the CNSC to ensure compliance with applicable guidelines and limits, as set out in regulations that govern Canada’s nuclear industry.

The CNSC has implemented an Independent Environmental Monitoring Program (IEMP) to independently verify that all persons and the environment around licensed nuclear facilities are protected. The IEMP is a regulatory tool that complements and informs the CNSC’s ongoing compliance verification program. The IEMP does not rely on licensees to provide samples. CNSC staff or independent contractors obtain samples from publicly accessible areas around the facilities, measuring and analyzing the amount of radiological and hazardous substances in these samples.

As part of the CNSC’s IEMP, samples were collected in three publicly accessible areas around the Cluff Lake site in 2017 and around the Deloro mine site in 2016. Results indicated that the public and the environment around the Cluff Lake site and the Deloro site are protected and there are no health impacts as a result of site operations. These results were consistent with results submitted by the respective licensees demonstrating that their environmental protection programs protect the health and safety of people and the environment. Results from IEMP sampling campaigns are available on the CNSC’s IEMP Web page.

### 1.3 Public information and community engagement

The CNSC is committed to keeping the public informed of regulatory activities occurring at operating mine and mill facilities. This is in accordance with its mandate to disseminate scientific, technical and regulatory information about its activities, and of the effects, on the environment and on the health and safety of persons, of the development, production, possession, transport and use of nuclear substances.

Ongoing CNSC public engagement efforts include meetings with stakeholders, updates to website information, and an ongoing social media presence. During public engagement activities, the CNSC often staffs a booth to provide important information on its regulatory role and mandate, as well as to answer any questions from community members.

To ensure that licensees provide open and transparent information to the public, the CNSC published new regulatory requirements in RD/GD-99.3, Public Information and Disclosure, in 2013. These requirements were then incorporated into each licence’s LCH. According to RD/GD‑99.3, licensees are required to implement and maintain public information and disclosure programs. These programs are supported by disclosure protocols that outline the type of information to be shared with the public on the operation or site and its activities (e.g., incidents, major changes to operations, periodic environmental performance reports) and how that information will be shared. These requirements ensure effective communication of timely information about the health and safety of persons, the environment and other issues associated with the lifecycle of nuclear facilities. CNSC staff confirmed through regulatory oversight activities that uranium mine and mills licensees implemented public information and disclosure programs in compliance with RD/GD‑99.3, in the reporting period covered by this document.

In 2017, licensees and CNSC staff continued regular communication with interested communities. As part of licensee public information programs and outreach activities, licensees and CNSC staff regularly participate in Northern Saskatchewan Environmental Quality Committee (EQC) meetings and facility tours. Established in 1995, the EQC represents more than 30 communities – many of which are Indigenous – throughout the greater northern Saskatchewan region. The committee enables Northerners to learn more about uranium mining activities and to see first-hand the environmental protection measures being employed in these operations. Regularly scheduled meetings of the Northern Saskatchewan EQC resumed in 2017; CNSC staff participate in EQC meetings when requested. Further information can be found on the EQC Web page.

#### Indigenous and public engagement

The CNSC is committed to ongoing engagement and relationship building with interested Indigenous communities. First Nations and MÃ©tis communities with interest in Canada’s uranium mines and mills were provided a copy of this regulatory oversight report. Through the CNSC’s Participant Funding Program (PFP), financial support was made available for participation in the review of this report. Last year, participant funding was awarded to five recipients for the review of the Regulatory Oversight Report for Uranium Mines and Mills in Canada: 2016 (YÃ¡’thi NÃ©nÃ© Land and Resource Office; Buffalo River Dene Nation; Birch Narrows Dene Nation; Sydon Consulting; and Saskatchewan Environmental Society). In addition, CNSC staff provided interested Indigenous communities with updates on IEMP sampling campaigns at uranium mine, mill, historic and decommissioned sites.

To ensure that licensees engage with Indigenous communities, the CNSC published REGDOC‑3.2.2, Aboriginal Engagement in 2016. REGDOC-3.2.2 sets out requirements and guidance for licensees proposing projects that may raise the Crown’s duty to consult. Throughout this reporting period, licensees continued to host meetings and to discuss their operations with Indigenous communities, and CNSC staff participated in many of these meetings.

Activities attended and carried out by CNSC staff in 2017 included the following:

• April 25, 2017 – Saskatchewan Mining Association Exhibition and Information session: The meeting was attended by approximately 300 students and community members from La Loche and surrounding areas.
• June 22, 2017 – Northern Mine Monitoring Secretariat update to the EQC: The meeting included EQC members, and various Government of Saskatchewan representatives.
• September 25–26, 2017 – Mining for Society: This two-day event, aimed at students in the Saskatoon area, showcased the mining industry. It was attended by approximately 700 students.
• October 17, 2017 – Fedoruk Center “coffee break” information session: This was a public event where CNSC staffed a presentation booth and answered questions.
• November 6, 2017 – Meeting with Ya’thi NÃ©nÃ© Land and Resource Office regarding PFP funding for the 2016 regulatory oversight report and information session. The meeting included representatives from the Athabasca Dene First Nations, CNSC, Cameco and AREVA. There were approximately 40 people in attendance.
• November 7, 2017 – Communication with Pinehouse, Kineepik MÃ©tis Local Inc., to answer questions regarding contaminated waste management at Key Lake.

A licence renewal hearing was held for the McClean Lake Operation in June 2017 in La Ronge, Saskatchewan. As part of this licence renewal, CNSC staff undertook focused engagement activities and actions. Per the CNSC’s public notification process for Commission proceedings, CNSC staff informed the public of the Commission hearing and availability of the PFP through the CNSC’s website, email subscription list, social media channels, and radio and print advertisements in local northern Saskatchewan communities. Participant funding was awarded to Birch Narrows Dene Nation and Buffalo River Dene Nation for a meeting with CNSC staff on May 25, 2017, to discuss the McClean Lake Operation licence renewal. CNSC staff remain committed to working with the many communities to better understand their interests and concerns.

The northern communities are heavily engaged in the activities associated with mine and mill operations as employees, suppliers and participants in numerous agreements. A report produced by the province of Saskatchewan, titled Benefits from Northern Mining, 2017 Summary, provides an overview of the benefits associated with mining in northern Saskatchewan. As of December 31, 2017, the northern mines employed over 2,400 people in direct and contract jobs. The mines maintain a high northern participation rate, with 48% of mine employees classified as Northerners. Northern mines are one of the largest employers of Indigenous peoples in Canada.

### 1.4 Decision on radionuclide reporting in National Pollutant Release Inventory

In response to a public request to add radionuclides to the National Pollutant Release Inventory (NPRI) substance list, this information has been made available and is provided in appendix K: Annual Releases of Radionuclides to the Environment.

The CNSC is making this data accessible as part of its mandate to disseminate this information to the public, and in demonstration of its commitment to open government. The original request to add radionuclides to the NPRI, the Government of Canada response, and the subsequent request from environmental non-governmental organizations are available upon request by contacting the NPRI program.

## Section I – Operating Uranium Mines and Mills

### 2. Overview

This section of the report focuses on the performance of the five uranium mines and mills operating in Canada in 2017. The facilities listed are located within the Athabasca Basin of northern Saskatchewan and are shown in figure 2.1:

• Cigar Lake Operation
• McArthur River Operation
• Rabbit Lake Operation
• Key Lake Operation
• McClean Lake Operation

The 2017 uranium production data for these operating mine and mill facilities are shown in table 2.1. CNSC staff confirmed that all facilities operated within their authorized annual production limits in 2017.

Table 2.1: Production data for operating uranium mines and mills, 2017
Production data1 Cigar Lake McArthur River Rabbit Lake2 Key Lake3 McClean Lake4
Mining – ore tonnage (Mkg/year) 36.49 91.44 0 N/A5 0
Mining – average ore grade mined (%U) 18.85% 7.09% 0% N/A 0%
Mining – U mined (Mkg U/year) 6.88 5.88 0 N/A 0
Milling – mill ore feed (Mkg/year) N/A N/A 0 143.26 36.35
Milling – average mill feed grade (%U) N/A N/A 0% 4.32% 19.30%
Milling – mill recovery (%U) N/A N/A 0% 99.05% 99.03%
Milling – U concentrate produced (Mkg U/year) N/A N/A 0 6.20 6.93
Authorized annual production (Mkg U/year) 9.25 9.6 4.25 9.6 9.23

1 1 Mkg = 1,000,000 kg.

2 Rabbit Lake was in a state of safe care and maintenance during this reported period.

3 At Key Lake, McArthur River ore is blended with stockpiled lower-grade material to produce a lower-grade mill feed.

4 The McClean Lake mill has been designed to mill high-grade ore from Cigar Lake without any blending or dilution.

5 N/A = not applicable.

Licensees are required to develop preliminary decommissioning plans and associated financial guarantees to ensure that work activities are covered financially and work is guaranteed for completion with no liability to the government. Financial guarantee values for the operating mine and mill facilities range from approximately C$48 million at the McArthur River Operation to C$218 million at the Key Lake Operation. The values of the financial guarantees are listed in appendix F. Financial guarantees cover all costs necessary to fully decommission and remediate a uranium mine and/or mill to ensure the protection of people and the environment.

#### 2.1 Regulatory efforts

The CNSC regulates the five uranium mine and mill operations under separate licences. Appendix A provides an outline of these licences and their respective licensing information. CNSC staff verified licensee compliance with regulatory requirements through activities such as inspections, reviews and assessments of reports and licensee programs. These compliance verification activities were supplemented with meetings, presentations and facility visits.

In 2017, CNSC staff performed six inspections at each uranium mine and mill operation for a total of 30 onsite inspections (these are outlined in appendix B). These inspections resulted in the identification of 23 instances of non-compliance, all of low safety significance. CNSC staff assessed all licensee corrective actions taken in response to non-compliance, and verified that these actions were appropriate and acceptable. All corrective actions implemented by licensees are considered closed.

#### 2.2 Performance

The CNSC’s safety and control area (SCA) performance ratings for operations were developed using professional judgment and expertise. Ratings are based on the review of key performance indicators (e.g., accident/event occurrences, responses to accidents/events, desktop review of reports, dose information, and both radiological and non-radiological environmental results) and the results of compliance activities, such as inspections and technical assessments.

Once established, ratings are compared across all five operating mines and mills and to the rating methodology defined in appendix D to ensure that consistent and defendable ratings are assigned. For 2017, CNSC staff assigned performance ratings of either “satisfactory” or “fully satisfactory” to operating uranium mines and mills. Table 2.2 presents the SCA ratings for each operating facility for 2017, and appendix E contains the SCA ratings for each facility (operating, historic and decommissioned) from 2013 to 2017.

Table 2.2: SCA performance ratings for operating uranium mines and mills, 2017
Safety and control area Cigar Lake McArthur River Rabbit Lake Key Lake McClean Lake
Management system SA SA SA SA SA
Human performance management SA SA SA SA SA
Operating performance SA SA SA SA SA
Safety analysis SA SA SA SA SA
Physical design SA SA SA SA SA
Fitness for service SA SA SA SA SA
Radiation protection SA SA SA SA FS
Conventional health and safety SA SA SA SA SA
Environmental protection SA SA SA SA SA
Emergency management and fire protection SA SA SA SA SA
Waste management SA SA SA SA SA
Security SA SA SA SA SA
Safeguards and non‑proliferation SA SA SA SA SA
Packaging and transport SA SA SA SA SA

FS = fully satisfactory

SA = satisfactory

This report focuses on the three SCAs that cover many of the key performance indicators for these facilities: radiation protection, environmental protection and conventional health and safety.

Licensees develop and maintain management systems that include integrated links to all 14 SCAs. Management systems are the framework that establish the processes and programs required to ensure an organization achieves its safety objectives, continuously monitors performance, identifies inadequacies, and continually improves and fosters a healthy safety culture. CNSC staff reviewed and assessed program performance and key performance indicators across radiation protection, environmental protection, and conventional health and safety management systems through regular compliance verification activities throughout 2017.

#### 2.3 Radiation protection

Uranium mine and mill licensees in Canada are required to implement and maintain radiation protection programs. Each program must ensure that contamination levels and radiation doses received by individuals are monitored, controlled and maintained below regulatory limits and as low as reasonably achievable (ALARA).

For 2017, CNSC staff rated the radiation protection SCA at all five operating facilities as “satisfactory” or “fully satisfactory”, based on regulatory oversight activities.

Radiation protection ratings
Cigar Lake McArthur River Rabbit Lake Key Lake McClean Lake
SA SA SA SA FS

FS = fully satisfactory

SA = satisfactory

##### Radiological hazard control

Sources of radiation exposure at uranium mines and mills include:

• gamma radiation
• long-lived radioactive dust
• radon progeny
• radon gas

CNSC staff’s compliance activities confirmed that these hazards were controlled by licensees’ radiation protection programs, including practices related to the effective use of time, distance and shielding; source control; ventilation; contamination control; and personal protective equipment.

##### Radiation protection program performance

During 2017, CNSC staff conducted regulatory oversight activities in the radiation protection SCA at all five operating facilities. These activities were to verify that licensees were complying with regulatory requirements for implementation of radiation protection programs.

Radiation protection programs include codes of practice that outline licensee administrative levels and action levels for exposures and doses of radiation. Administrative levels include a list of specific actions to be taken by the licensee based on radiological monitoring in the workplace. The radiation protection programs include actions to be taken under specific conditions; for example:

• “continue to work while monitoring or investigating a parameter”
• “leave the area and initiate an investigation”

As radiation levels or worker exposure levels increase, the required protective actions become more stringent.

Administrative levels are identified for all radiological hazard types, apply to normal operating conditions, and are used to ensure optimal conditions for workers. Licensees are responsible for identifying the parameters of their programs that represent timely indicators of potential losses of control. For this reason, action and administrative levels are licensee-specific and may change over time depending on operational and radiological conditions. If an action level is reached, it may indicate a loss of control of part of a licensee’s radiation protection program. The licensee is then required to establish the cause, notify the CNSC, and, if applicable, restore the effectiveness of the radiation protection program.

The five operating uranium mines and mills have the same individual radiation dose action level of 1 millisievert (mSv) per week and 5 mSv per quarter of a given year. No radiation-related action levels were reported by the operating mines and mills in 2017.

Figure 2.2 shows a CNSC inspector taking a gamma dose rate measurement at the McArthur River water treatment holding pond.

CNSC staff confirmed that, during the reporting period, the radiation protection programs and practices at operating mines and mills remained effective in controlling radiological exposure to workers. No action levels were reached in 2017.

##### Application of ALARA

The radiation protection programs established by uranium mine and mill licensees include responsibilities and processes for ensuring that exposures to workers are maintained ALARA.

Through scheduled compliance oversight activities, CNSC staff verified that key elements of these ALARA programs (e.g., management control over work practices, personnel qualification and training, control of occupational and public exposure to radiation, and planning for unusual situations) were effectively implemented by uranium mine and mill licensees in 2017.

This report includes the reporting of annual collective dose values for nuclear energy workers (NEWs), for each operating mine and mill (see sections 3.2, 4.2, 5.2, 6.2 and 7.2). The collective dose value is the sum of the effective doses received by all NEWs at a uranium mine and mill in one year. Collective dose is a radiation protection performance indicator that provides the total exposures associated with each operation. It supplements other performance statistics, like average dose, which have been affected by factors including changes in the number of workers or workers who receive radiation exposures over very short periods of time. Collective dose shows the effect of increased or reduced site activities; for example, the transition of the Rabbit Lake Operation from active mining and milling of ore to a “care and maintenance” status (see figure 5.3), or the ramping up of production at the McClean Lake Operation (see figure 7.3).

##### Worker dose control

In accordance with the Radiation Protection Regulations, licensee radiation protection programs include processes and criteria to provide assurance that all individuals identified as NEWs, in accordance with section 2 of the NSCA, are appropriately designated and trained. This includes licensee employees and contractors. Radiation exposures are ascertained through approved dosimetry methods, and workers are notified of the results.

At all operating uranium mines and mills, NEWs are issued optically stimulated luminescence dosimeters that measure external gamma radiation exposure and resulting doses. Where required, workers also wear personal alpha dosimeters (PADs) to measure alpha radiation exposure from radon progeny and radioactive dust. Optically stimulated luminescence dosimeters and PAD readings are measured by a CNSC-licensed dosimetry service provider. Where direct monitoring through dosimeters is not warranted, approved dose estimation methods (such as area/group monitoring and time cards) are used in accordance with CNSC regulatory guidance. CNSC staff confirmed that all licensees for the operating facilities discussed in this report met regulatory requirements for the use of licensed dosimetry, during the reporting period.

Figures 2.3 and 2.4 show the average individual effective doses and maximum individual effective doses during the 2013 to 2017 reporting period for the five operating facilities. In 2017, no worker at any facility exceeded the regulatory individual effective dose limit of 50 mSv in one year and 100 mSv in a five-year dosimetry period.

Increases and decreases over time in effective dose to NEWs are explained in facility-specific sections of this report (sections 3.2, 4.2, 5.2, 6.2 and 7.2) under “worker dose control”.

The highest maximum individual effective dose to a worker at an operating uranium mine and mill in 2017 occurred at the McArthur River facility. A dose of 5.73 mSv was assigned to an underground process worker who regularly worked in the semi-autogenous grinding mill area. This value is 11.5% of the annual dose limit of 50 mSv.

Appendix G shows the number of NEWs at each operating facility, with corresponding average individual effective doses and maximum individual effective doses, for the 2013 to 2017 period.

##### Estimated dose to the public

Uranium mine and mill operations are remote from local populations. The Radiation Protection Regulations set a public radiation dose limit of 1 mSv per year above natural background radiation, to ensure protection of the health of the public. Radiological exposures measured at the boundaries of these remote licensed facilities are close to background radiation levels. As published in the CNSC fact sheet on natural background radiation, the background radiation level for Canada is approximately 1.8 mSv.

In 2017, CNSC staff were satisfied that uranium mine and mill licensees controlled radiation doses to persons at levels well below regulatory limits, and that licensees kept doses ALARA.

This conclusion was based on the outcome of inspections, as well as reviews of licensees’ radiation protection programs, radiological hazard control, worker dose control and application of the ALARA principle.

#### 2.4 Environmental protection

The environmental protection SCA covers programs that identify, control and monitor releases of radioactive and hazardous substances and effects on the environment from facilities as a result of licensed activities.

Based on regulatory oversight activities, CNSC staff rated the 2017 performance of all five operating uranium mine and mill facilities for the environmental protection SCA as “satisfactory”. CNSC staff concluded that licensees’ environmental protection programs were effectively implemented and met all regulatory requirements.

Environmental protection ratings
Cigar Lake McArthur River Rabbit Lake Key Lake McClean Lake
SA SA SA SA SA
SA = satisfactory
##### Environmental management system

The CNSC requires licensees to develop and maintain environmental management systems that provide a framework for integrated activities related to environmental protection at their operations. Environmental management systems are described in approved environmental management programs and include activities such as establishing annual environmental objectives, goals and targets. Licensees conduct internal audits of their programs as identified in their CNSC-approved management system program. Through regular compliance verification activities, CNSC staff confirmed that licensees’ objectives, goals and targets were met in 2017. Site-specific details are provided in sections 3.3, 4.3, 5.3, 6.3 and 7.3 of this report.

##### Environmental risk assessment

The CNSC uses site-specific, licensee-developed environmental risk assessments (ERAs) as a regulatory tool throughout the lifecycle of uranium mine and mill facilities. Applicants use ERAs during initial environmental assessments for new facilities and for changes to existing facilities or activities at licensed operations, where applicable. The ERA identifies the need for mitigation technologies or practices, and it predicts:

• physical disturbances
• releases to the atmosphere
• changes to surface water quality
• changes to groundwater quality
• changes to the physical environment
• any biological effects

Operating uranium mines and mills are required to submit updated ERAs to the CNSC every five years. ERAs are typically updated based on operational activities, revised predictions, historic monitoring information and the latest science. CNSC staff regularly review ERAs to determine potential risks to human health and the environment and to verify that mitigation measures are adequate.

##### Assessment and monitoring

In accordance with the Uranium Mines and Mills Regulations, each uranium mine and mill licensee has an environmental monitoring program that monitors releases of nuclear and hazardous substances, and to characterize any effects to the environment associated with the licensed facility. Nuclear and hazardous substances associated with monitoring programs are selected based on regulated contaminants and constituents of potential concern (COPC) identified through the licensee’s ERA. COPC identified through the ERA with the potential for adverse environmental effects are managed through increased monitoring, inclusion in the environmental code of practice, and further study or implementation of additional controls by the licensee. CNSC staff periodically review environmental monitoring programs as criteria for assessing environmental performance.

Environmental monitoring programs are associated with an environmental code of practice that sets out administrative levels and action levels for select COPC with the potential for adverse environmental effects. An administrative level represents the upper range of design specifications for a specific parameter. Reaching an administrative level triggers an internal review by the licensee. Exceedance of an action level indicates a potential loss of control of the environmental protection program, which is based on the approved facility design envelope, and triggers actions that must be taken by the licensee to correct the problem. This requires notification to the CNSC, an immediate investigation, subsequent corrective actions and preventive measures, in order to restore the effectiveness of the environmental protection program. It is important to recognize that an exceedance of an action level does not imply a potential risk to the environment, but identifies that the operating parameter may be outside the facility design envelope. Facility administrative and action levels are determined through the identification and proper operation of existing treatment technologies, as well as facility-specific environmental risk studies.

In 2017, there were no action level exceedances for treated effluent released to the environment.

CNSC staff have reviewed environmental risk assessments and environmental monitoring results of operating uranium mine and mill facilities and have concluded that the environment was protected during the reporting period.

##### Uncontrolled releases

For any unauthorized releases (spills) of hazardous or radioactive substances to the environment, licensees are required to report to regulatory authorities, including the CNSC,

Figure 2.5 depicts the number of environmental reportable spills for uranium mine and mill facilities during the 2013 to 2017 reporting period. In each case, CNSC staff reviewed the licensee’s actions to ensure effective remediation and prevention, and they were satisfied with actions taken by the licensee. CNSC staff rated all 2017 spills as “low significance” resulting in no residual impact to the environment.

The site-specific sections and appendix H of this report describe each reportable spill and any corrective actions taken by the licensee in response. The CNSC spill rating definitions are also found in appendix H.

##### Protection of the public

According to regulatory requirements, each licensee must demonstrate that the public is protected from exposures to radiological and hazardous substances released from an operation. Protection of the public is assessed in the ERA, which contains a human health risk assessment (HHRA). The HHRA assesses hazardous and radiological releases from operating facilities, and it models resultant concentrations of contaminants in air, water, soil and traditional foods, such as fish, waterfowl and moose. The concentrations of contaminants consumed by a typical local resident are assessed against human health benchmarks in the HHRA. For all operating facilities, the HHRAs confirmed that concentrations of contaminants for a typical local resident were well below concentrations that could cause health effects, in 2017. It was therefore determined that the health of the public in areas surrounding the operating facilities was protected.

###### Eastern Athabasca Regional Monitoring Program

The Eastern Athabasca Regional Monitoring Program (EARMP) is a well-recognized environmental monitoring program designed to gather data on long-range environmental information and potential cumulative impacts downstream of uranium mining and milling operations. The program, which was established by the province of Saskatchewan in 2011, monitors the safety of traditionally harvested country foods through analysis of water, fish, berries and wild meat, (e.g., grouse, rabbit, caribou and moose) from representative northern Saskatchewan communities. The program contractor is a northern Saskatchewan Indigenous‑owned business. The program involves the collection of samples from areas identified by community members, who either assist with sample collection or provide samples from their own harvesting activities.

Harvesting and consuming traditional country foods is an important part of the culture in northern Saskatchewan. The intent of the EARMP is to provide confidence and to communicate transparently to community members that traditional country foods remain safe to eat, both today and in future generations. The program has demonstrated that concentrations of chemicals of interest have been relatively consistent over time and generally within the regional reference range, indicating little evidence of long-range transport of contaminants associated with uranium mining.

Evaluation of country food data from previous years confirms that operating uranium mines and mills are not affecting the safety of country foods in nearby communities. The results indicated that radiological and non-radiological exposures of residents consuming country foods were similar to exposures of the general Canadian population, and were also below values considered to be protective of health effects. The EARMP has proven to be a productive means of involving community members in monitoring the health of their local environment, and it has provided them with confidence in the safety of their traditional foods. The conclusion of the EARMP is that water and country foods are considered safe for consumption.

The complete report and data are available on the EARMP website.

CNSC staff continue to support the EARMP and are working to further collaborate on opportunities for this valuable program.

##### Effluent and emissions control
###### Treated effluent released to the environment

Licensee-developed ERAs had previously identified releases of molybdenum, selenium and uranium as COPC with potential for adverse environmental effects, across multiple operating uranium mines and mills. As a result, improved engineering controls and treatment technologies to reduce effluent releases of these contaminants were implemented where required. In 2017, the implemented treatment technologies continued to keep these contaminant concentrations stable, below regulatory limits and ALARA. Figures 2.6 to 2.8 display the average annual effluent concentrations for molybdenum, selenium and uranium at the five operating mines and mills, from 2013 to 2017.

In the absence of federal or provincial limits for molybdenum, the CNSC required licensees to develop facility-specific effluent controls within their environmental protection program codes of practice. From 2013 to 2017, average effluent concentrations of molybdenum at the five operating uranium mines and mills were below the action level in the Key Lake code of practice. (Of the five operations, Key Lake has the most stringent action level for molybdenum. This action level is shown for reference only.)

Figures 2.7 and 2.8 demonstrate that both selenium and uranium concentrations in treated effluent released to the environment, from operating mine and mill facilities from 2013 to 2017, remained below Saskatchewan’s licensed effluent discharge limits of 0.6 mg/L and 2.5 mg/L for selenium and uranium, respectively. As indicated on figure 2.8, the CNSC identified an interim objective for uranium of 0.1 mg/L. This was derived based on treatment technologies in place at the uranium mines and mills and based on what would be achievable by the uranium metal mining sector. The interim objective was applied to all uranium mine and mill facilities since it was the most stringent and it has been consistently met. This interim objective for uranium in effluent is in place until the CNSC requirements for release limits are published in REGDOC-2.9.2, which was in development at the time of this report’s publication.

In addition to the preceding figures that show COPC with the potential for adverse environmental effects, the graph in figure 9 displays radium concentrations. The 2013 to 2017 annual average effluent concentrations of radium-226, for the five operating mines and mills, were well below the CNSC’s licence-authorized effluent discharge limit of 0.37 Bq/L.

Uranium mine and mill facilities also analyze treated effluent for concentrations of other regulated contaminants and COPC, such as arsenic, copper, lead, nickel, zinc, total suspended solids (TSS), as well as pH levels. Table 2.3 displays the annual average parameter concentration values in effluent for these substances released in 2017, as well as the discharge limits described in the Metal Mining Effluent Regulations (MMER). All metal mines and mills in Canada are subject to MMER, which are made under the federal Fisheries Act. CNSC uranium mine and mill licences incorporate the effluent limit requirements of the MMER. In 2017, all treated effluent released to the environment from the five operating mines and mills – for the preceding substances including pH – did not exceed the effluent discharge limits.

Table 2.3: Annual average parameter concentration values in treated effluent released to the environment, 2017
Parameters MMER discharge limit Cigar Lake McArthur River Rabbit Lake Key Lake McClean Lake
Arsenic (mg/L) 0.5 0.0750 0.0012 0.0010 0.0080 0.0260
Copper (mg/L) 0.3 0.0006 0.0010 0.0002 0.0230 0.0030
Lead (mg/L) 0.2 0.0001 0.0009 0.0001 0.0100 0.0020
Nickel (mg/L) 0.5 0.0008 0.0037 0.0017 0.1670 0.0150
Zinc (mg/L) 0.5 0.0259 0.0014 0.0006 0.0090 0.0030
Molybdenum (mg/L) N/A 0.0640 0.1460 0.1390 0.1200 0.0040
Selenium (mg/L) N/A 0.0042 0.0036 0.0024 0.0150 0.0110
TSS (mg/L) 15 1 1 1 3 2
pH range 6.0–9.5 7.3 7.4 7.3 6.5 7.2

In 2017, average parameter concentration values in treated effluent released to the environment, from the licensed mining and milling activities at the five operating mines and mills, did not exceed the effluent discharge limits stipulated in CNSC operating licence documentation.

CNSC staff will continue to review effluent quality results to ensure that effluent treatment performance remains effective.

###### Air emissions released to the environment

Environmental programs at uranium mines and mills include monitoring the effects of operations on the surrounding air and soil. Licensees measure airborne particulate levels and concentrations of regulated contaminants and COPC, as well as the concentration of radon gas in ambient air. Soil and vegetation may be affected by atmospheric deposition of particulate containing adsorbed metals and radionuclides associated with onsite activities. Licensees monitor contaminant concentrations in soil and terrestrial vegetation to verify that operational impacts are ALARA and below regulatory limits.

Facilities with milling operations monitor atmospheric emissions from acid plants, yellowcake dryers, calciner operations, packaging, grinding and ammonium sulphate operations. Other measured parameters (e.g., ambient radon and stack testing for sulphur dioxide, uranium and heavy metals) verify facility design and evaluate the operation’s performance against predictions made in ERAs.

CNSC staff verified that the operating mines and mills demonstrated satisfactory performance in mitigating and monitoring the effects of their operations on the surrounding air and soil, during 2017. Some air and soil samples taken from around the facilities indicated emission levels that were slightly above background concentrations in the immediate vicinity of activities; however, concentrations decreased to background levels within a short distance (less than 2 km from the site boundary). The monitoring results indicated negligible impacts to the environment from atmospheric releases, and confirmed that all operating uranium mines and mills complied with their programs and provincial standards, in 2017.

###### Treated mining/milling effluent: A comparison of the uranium mining sector to other metal mining sectors across Canada

As noted previously in this report, metal mines and mills in Canada are subject to the MMER of the federal Fisheries Act. The quality of effluent treatment by the uranium mining sector compares favourably to that of other metal mining sectors (base metal, precious metal and iron) across Canada.

The data used for analysis and comparison are acquired from Environment and Climate Change Canada. MMER data from 2016 are used for comparison within this report since they comprise the most current sector-specific MMER information available, with the exception of molybdenum, selenium and uranium, for which 2017 data are available. The mines reporting under the MMER and that released treated effluent are grouped into four metal mining sectors based on the primary metal produced. The metal mining sectors are:

• uranium – 5 facilities
• base metals (such as copper, nickel, molybdenum or zinc) – 47 facilities
• precious metals (such as gold or silver) – 54 facilities
• iron – 8 facilities

Molybdenum is a parameter requiring routine monitoring of treated effluent subject to the MMER. Ecological risk assessments completed in the mid-2000s indicated that releases of molybdenum posed a risk to biota, and that this risk merited adaptive management. As a result of a request from Commission members, CNSC licensees of uranium mines and mills incorporated administrative and treatment technology upgrades in their effluent management systems. The success of these actions is evident in figure 2.10, which shows a substantial decrease in molybdenum releases in the uranium mining sector.

In 2017, molybdenum concentrations in uranium mining sector effluent were similar to those measured in effluent of precious metal and iron mines, and less than those measured in effluent of base metal mines.

In mid-2012, a requirement for monitoring selenium was added to the MMER. Table 2.4 summarizes the average selenium concentration in treated effluent from each mining sector using data collected since 2012. Selenium concentration in uranium sector effluent was similar to that of other metal mining sectors in Canada.

Table 2.4: Average selenium concentration in treated effluent by metal mining sector, second half of 2012 and all of 2013–17
Year Metal mining sector
Uranium (mg/L) Base metals (mg/L) Precious metals (mg/L) Iron (mg/L)
2012–13* 0.003 0.005 0.005 0.001
2014 0.004 0.006 0.005 0.001
2015 0.004 0.005 0.004 0.004
2016 0.008 0.006 0.003 0.003
2017 0.004 0.008 0.004 0.001
*Data from 2012 is for the second half of the year only.

Uranium concentrations were also recently added to the parameters required to be monitored and reported on under the MMER. Table 2.5 presents the average uranium concentrations in treated effluent by metal mining sectors. As shown in table 2.5, the uranium sector had an average concentration of 0.0185 mg/L of uranium in 2017. Uranium mines have elevated natural uranium concentrations compared to other conventional mining operations. By way of comparison and to provide context, the action level in the environmental code of practice and the Saskatchewan regulatory limits for uranium are 0.3 mg/L and 2.5 mg/L, respectively. CNSC staff continue to verify that releases of uranium are controlled and reduced to the extent practicable through reviews of effluent quality data, scrutiny of proposed facility changes that could affect effluent quality, and validation of the effectiveness of licensee programs to minimize releases of contaminants.

Table 2.5: Average uranium concentration in treated effluent by metal mining sector, 2017
Year Metal mining sector
Uranium (mg/L) Base metals (mg/L) Precious metals (mg/L) Iron (mg/L)
2017 0.0185* 0.0062 0.0027 0.0002
* Data not available from Environment and Climate Change Canada; value was calculated from licensee annual reports.
##### Metal Mining Effluent Regulations performance indicators

The MMER specify the maximum concentration limits in effluent for the following regulated parameters: arsenic, copper, lead, nickel, zinc, radium-226, TSS and an allowable pH range. Effluent must also be non-toxic, which is determined through rainbow trout acute lethality testing. The effluent treatment performance of the four metal mining sectors is compared using the following three performance indicators: compliance with MMER limits for effluent concentration and pH; annual average effluent concentrations in the metal mining sectors; and toxicity test results. These three performance indicators are further described below.

###### 1) Compliance with MMER limits for effluent concentration and pH

Table 2.6 illustrates the number of mines that did not comply with MMER effluent standards for at least one regulated parameter (excluding acute-toxicity tests in 2016). These data are used to assess if compliance with the parameters of MMER is a sector-wide concern.

Two gold metal mines had effluent with radium concentrations above the MMER limit for portions of the year. The uranium mines were in full compliance with the provisions of the MMER.

Table 2.6: Number of mines that did not comply with MMER limits for effluent concentration and pH by mining sector, 2016*
Parameter Mining sector
Uranium Base metals Precious metals Iron
Arsenic 0 0 0 0
Copper 0 0 0 0
Lead 0 0 0 0
Nickel 0 1 0 0
Zinc 0 0 0 1
TSS 0 6 4 2
Radium-226 0 0 2 0
pH range 0 3 1 3
Mines out of compliance with at least one parameter** 0 10 6 5
Number of mines 5 47 54 8

*    2016 data is the most current sector-specific data available from Environment and Climate Change Canada.

** A mine may have more than one parameter out of compliance; therefore, the number of mines out of compliance with at least one parameter may not equal the sum of the number of mines listed as out of compliance with individual parameters.

###### 2) Annual average effluent concentrations in the metal mining sectors

Table 2.7 compares the 2016 average effluent concentrations in the metal mining sectors. CNSC staff noted that the effluent concentrations of radium-226 for base metal and precious metal mines are similar to those of uranium mines.

Table 2.7: Sector comparison of average effluent concentrations by parameter, 2016*
Parameter** MMER discharge limits Uranium Base metals Precious metals Iron
Arsenic (mg/L) 0.5 0.022 0.005 0.022 0.003
Copper (mg/L) 0.3 0.003 0.009 0.014 0.006
Lead (mg/L) 0.2 0.0002 0.003 0.001 0.003
Nickel (mg/L) 0.5 0.027 0.045 0.018 0.008
Zinc (mg/L) 0.5 0.010 0.051 0.019 0.026
TSS (mg/L) 15 1.0 3.3 4.2 4.3
Radium-226 (Bq/L) 0.37 0.023 0.025 0.023 0.007
pH range 6.0–9.5 7.0 7.7 7.6 7.4

* 2016 data is the most current sector-specific data available from Environment and Climate Change Canada.

** Uranium is required to be monitored and reported under the MMER. It is not regulated to a specified concentration.

###### 3) Toxicity test results

Effluent toxicity is measured using the rainbow trout acute lethality test. As the world standard toxicity test for fresh-water, cool-climate conditions, this test has been part of Canadian regulations and guidelines for four decades. In this test, rainbow trout fingerlings or swim-up fry (0.3 g to 2.5 g wet weight) are reared under controlled conditions. They are then placed in undiluted effluent for 96 hours. If less than half of the fish survive, the effluent is deemed acutely lethal. Effluent must be non-acutely lethal to pass the test as a requirement of MMER.

Table 2.8 displays the number of pass and fail results of rainbow trout acute lethality tests for the metal mining sectors in 2016. The uranium mining metal sector passed all required tests in 2016.

MMER limit Uranium Base metals Precious metals 31 419 492 147 0* 2 45 1 * Key Lake failed one test, but this test result was later confirmed to be invalid.

A mine is considered compliant if, throughout the year, its effluent passes all trout acute lethality tests. Table 2.9 summarizes the performance of the metal mining sectors. The uranium mine and mill facilities passed all acute lethality tests from 2012 to 2016.

Table 2.9: Percentage of mines in each metal mining sector passing all trout acute lethality tests, 2012–16
Metal mining sector 2012 2013 2014 2015 2016
Uranium 100% 100% 100% 100% 100%
Base metals 98% 93% 98% 92% 96%
Precious metals 94% 86% 96% 98% 91%
Iron 100% 100% 71% 75% 88%

#### 2.5 Conventional health and safety

The conventional health and safety SCA covers the implementation of a program to manage workplace safety hazards and protect personnel and equipment. Uranium mines and mills must develop, implement and maintain effective safety programs to promote safe and healthy workplaces and to minimize incidences of occupational injuries and illnesses.

For 2017, CNSC staff rated the conventional health and safety SCA at operating uranium mine and mill facilities as “satisfactory” following acceptable performance in health and safety practices, awareness and performance.

Conventional health and safety ratings
Cigar Lake McArthur River Rabbit Lake Key Lake McClean Lake
SA SA SA SA SA
SA = satisfactory
##### Practices

The CNSC requires licensees to identify potential safety hazards, assess associated risks, and introduce the necessary materials, equipment, programs and procedures to effectively manage, control and minimize these risks. CNSC staff work with the Saskatchewan Ministry of Labour Relations and Workplace Safety to provide regulatory oversight of conventional health and safety in uranium mines and mills. CNSC staff’s compliance verification activities include inspections, reviews of compliance reports and health and safety events.

CNSC staff confirmed that licensees at operating mines and mills implemented effective management of conventional health and safety in their activities. In addition to CNSC staff’s regulatory oversight, the Province of Saskatchewan, through an agreement with the Government of Canada, conducts regular inspections in the areas of occupational health and safety, mine safety and fire protection.

##### Awareness

CNSC staff observed that the implementation of conventional health and safety programs continued to provide education, training, tools and support to workers (see figure 2.11 for an example). Each facility licensee promotes the idea that safety is the responsibility of all individuals, and this message is reinforced by management, supervisors and workers. Management stresses the importance of conventional health and safety through regular communication, management oversight, and continual improvement of safety systems. Through onsite inspections, CNSC staff have identified a high level of communication and awareness in the area of conventional health and safety. CNSC staff concluded that, in 2017, licensees of operating uranium mines and mills were committed to accident prevention, safety awareness, and a focus on safety culture.

##### Performance

A key performance measure for conventional health and safety is the number of lost-time injuries (LTIs) that occur per facility. An LTI is a workplace injury that results in the worker being unable to return to work for a period of time. In reviewing each LTI, CNSC staff consider the injury’s severity and frequency rates. Table 2.10 shows the number of LTIs at the operating uranium mines and mills, along with severity and frequency rates.

Cigar Lake McArthurRiver Rabbit Lake Key Lake McClean Lake 0 1 0 0 0 0 12.1 0 0 67.8 0 0.15 0 0 0 1 An injury that takes place at work and results in the worker being unable to return to work for a period of time. 2 A measure of the total number of days lost to injury for every 200,000 person-hours worked at the site. Accident severity rate = [(# of days lost in last 12 months) / (# of hours worked in last 12 months)] x 200,000. 3 A measure of the number of LTIs for every 200,000 person-hours worked at the site. Accident frequency rate = [(# of injuries in last 12 months) / (# of hours worked in last 12 months)] x 200,000.

Appendix I provides more detail on the 2017 LTI at McArthur River and corrective actions taken. The severity rate for McClean Lake is due to events that took place prior to 2017 but resulted in lost time in 2017. Information on these events can be found in section 7.4. CNSC staff and the Saskatchewan Ministry of Labour Relations and Workplace Safety monitor and review each reportable injury to ensure the cause is identified and corrective actions taken are satisfactory. When applicable, injury information is shared among the facilities for lessons learned to improve safety and prevent recurrences.

CNSC staff concluded through their compliance verification activities that the health and safety programs at all uranium mines and mills met regulatory requirements in 2017.

###### Lost-time injuries: Comparison of the uranium mining sector to other mining sectors in Saskatchewan

Table 2.11 displays the various safety statistics of mining sectors within Saskatchewan. When contractors are excluded, the uranium mining and milling sector exhibits performance similar to other mining sectors for LTIs and frequency rate. The uranium sector comparison excludes contractors because statistics for the other sectors do not include contractors.

Table 2.11: Safety statistics of mining sectors in Saskatchewan, 2017
Mining sector Number of LTIs Accident frequency rate1 Accident severity rate2
Potash (underground) 9 0.2 7.3
Solution (potash)3 1 0.2 3.7
Minerals (sodium sulphate, sodium chloride) 3 0 0 0
Hard rock (gold, diamond)3 6 0.4 34.8
Coal (strip mining)3 10 2.1 63.9
Uranium3 1 0.0 23.3
Uranium (including contractors)4 1 0.0 16

1 A measure of the total number of days lost to injury for every 200,000 person-hours worked at the site.
Accident severity rate = [(# of days lost in last 12 months) / (# of hours worked in last 12 months)] x 200,000.

2 A measure of the number of LTIs for every 200,000 person-hours worked at the site.
Accident frequency rate = [(# of injuries in last 12 months) / (# of hours worked in last 12 months)] x 200,000.

3 Source: Saskatchewan Ministry of Labour Relations and Workplace Safety.

4 Statistics for all the other mining sectors do not include contractors.

CNSC staff completed a benchmarking effort to compare the injury frequency rate of Saskatchewan uranium mines and mills against national and international mining statistics. One limitation to consider when comparing safety-related statistics is the variation in workplace injury definitions. However, efforts are made where possible to compare and assess licensee performance with respect to relevant national and international benchmarks. Table 2.12 shows various international benchmarks related to workplace frequency rates. The uranium mining and milling sector in Canada exhibits similar, if not, more favorable performance.

Table 2.12: National/international benchmarking related to workplace safety
Publication/Standard Frequency rate Notes
Government of Western Australia Department of Mines, Industry Regulation and Safety1 2.3, 3.1

2.3 across all mining sectors

3.1 in non-metal mining environments; rates are per million hours worked for 2016–17

International Council on Mining and Metals2 4.3 Average rate are per million hours worked for 2016, based on statistics from 27 of the largest international mining companies
2017 Workplace Fatality and Injury Rate Report – Canada3 1.9 Average rate across all Canadian provinces and territories per million hours worked
The National Institute for Occupational Safety and Health4 (U.S.) 1.7 Average rate per 200,000 hours worked in 2015

1. Safety performance in the Western Australian mineral industry 2016–17, Government of Western Australia, Department of Mines, Industry Regulation and Safety, 2018.

2. Benchmarking 2016 Safety Data: progress of ICMM Members, International Council on Mining and Metals.

3. 2017 Workplace Fatality and Injury Rate, Tucker. S, University of Regina, 2017.

4. Number and rate of mining nonfatal lost-time injuries by year, 2006–15, The National Institute for Occupational Safety and Health.

### 3. Cigar Lake Operation

Cameco Corporation is the operator of the Cigar Lake Operation, which is located approximately 660 kilometres north of Saskatoon, Saskatchewan.

The Cigar Lake Operation consists of an underground uranium mine with surface facilities for loading ore slurry into trucks, waste management facilities, water treatment plant, surface freeze plants, administration offices and warehouses. Figure 3.1 shows an aerial view of the Cigar Lake Operation and figure 3.2 provides an annotated map.

The Cigar Lake uranium deposit is mined by mass freezing the orebody and surrounding country rock. Hydraulic water jets then extract the ore as a slurry (mixture of rock and water), which is pumped to surface, loaded into containers and transported 70 kilometres by truck to AREVA’s McClean Lake Operation for milling.

A public Commission hearing was held on April 3, 2013 in Saskatoon, Saskatchewan for the renewal of the Cigar Lake licence. The Commission issued an eight-year licence valid from July 1, 2013 to June 30, 2021.

Table 3.1 shows mining production data for 2013 through 2017. Cigar Lake mine commenced commercial production in spring 2014. Ore production increased during 2015 to achieve current production rate.

2013 2014 2015 2016 2017 0.234 3.32 21.6 37.27 36.49 17.09 6.02 22.92 18.27 18.85 0.04 0.2 4.95 6.81 6.88 9.25 9.25 9.25 9.25 9.25 1. 1 Mkg = 1,000,000 kg.

CNSC staff confirmed the Cigar Lake Operation production remained lower than the authorized CNSC licence limit for the 2017 calendar year, and that the licensee was carrying forward a cumulative shortfall of 12.7 million kilograms of uranium. This shortfall can be recouped in future years by increased production.

Construction activities in 2017 focused on additional infrastructure to sustain production plans, which include increased ground-freezing capacity and improved underground distribution of concrete.

#### 3.1 Performance

The safety and control area (SCA) ratings at Cigar Lake for the 2013 to 2017 five‑year period are shown in appendix E. For 2017, CNSC staff rated all 14 SCAs for the Cigar Lake Operation as “satisfactory”.

In 2017, CNSC staff carried out compliance inspections covering the SCAs of waste management, packaging and transport, human performance management, physical design, operating performance, fitness for service, safety analysis, radiation protection, environmental protection, and conventional health and safety. There was one instance of non-compliance resulting from CNSC inspections at the Cigar Lake Operation for the 2017 calendar year. This non-compliance was of low risk and related to the radiation protection SCA. The licensee implemented corrective actions, which were reviewed and accepted by CNSC staff. A complete list of inspections can be found in appendix B.

This report focuses on the three SCAs that cover many of the key performance indicators for operating mines and mills: radiation protection, environmental protection, and conventional health and safety.

#### 3.2 Radiation protection

For 2017, CNSC staff continued to rate the radiation protection SCA at Cigar Lake as “satisfactory” based on regulatory oversight activities.

Cigar Lake Operation – Radiation protection ratings
2013 2014 2015 2016 2017
SA SA SA SA SA
SA = satisfactory
##### Radiological hazard control

The main source of radiological exposure at the Cigar Lake Operation is from mining high-grade uranium ore. The contributors to effective doses to nuclear energy workers (NEWs) at Cigar Lake remained similar to previous years, with gamma radiation (34%), radon progeny (36%) and long‑lived radioactive dust (LLRD) (30%). Gamma radiation hazards are controlled through practices related to the effective use of time, distance and shielding. Exposures to radon progeny and LLRD are controlled through source control, ventilation, contamination control and personal protective equipment.

##### Radiation protection program performance

CNSC staff confirmed that the radiation protection program and practices at the Cigar Lake Operation remained effective in controlling radiological exposure to workers. There were no effective dose action levels or regulatory exceedances at the Cigar Lake Operation in 2017.

##### Application of ALARA

In 2017, the collective radiation exposure to NEWs at the Cigar Lake Operation was 376 person‑millisieverts (p-mSv), an approximate 22.1% reduction from the 2016 value of 483 p‑mSv (see figure 3.3). This decrease was attributed to effective implementation of the Cigar Lake Operation’s radiation protection program.

Efforts to keep worker exposures as low as reasonably achievable (ALARA) included ongoing assessment of activities and areas with higher levels of risk for radon progeny exposures. While the assessments have demonstrated that the procedural controls in place are effective, engineering improvements were applied to reduce or eliminate the risk of exposure to elevated levels of radon progeny. Throughout 2017, Cameco focused on reducing radiation exposures to the hydraulic water jet machine operators (a higher-dose work group at the Cigar Lake Operation). The effort resulted in a reduction in annual average operator exposure from 2.87 mSv in 2016 to 2.22 mSv in 2017. CNSC staff concluded that the radiation protection program remained effective in ensuring that worker exposures remain ALARA.

##### Worker dose control

During 2017, the average individual effective dose to NEWs was 0.34 millisieverts (mSv) and the maximum individual effective dose was 3.36 mSv. This compares to an average effective dose of 0.39 mSv and a maximum individual dose of 5.53 mSv in 2016. As indicated in figures 2.3 and 2.4, no worker exceeded the regulatory individual effective dose limit of 50 mSv in one year and 100 mSv in a five-year dosimetry period.

Based on compliance verification activities that included site inspections, reviews of licensee reports, work practices, monitoring results and individual effective dose results for 2017, CNSC staff were satisfied that the Cigar Lake Operation continued to be effective in controlling radiation doses to workers.

#### 3.3 Environmental protection

For 2017, CNSC staff continued to rate the environmental protection SCA as “satisfactory”. CNSC staff concluded that the licensee’s environmental protection program was effectively implemented and met all regulatory requirements.

Cigar Lake Operation – environmental protection ratings
2013 2014 2015 2016 2017
SA SA SA SA SA
SA = satisfactory
##### Environmental management system

The CNSC-approved environmental management system is described in the Cigar Lake Operation environmental management program and includes activities such as establishing annual environmental objectives, goals and targets, all of which are reviewed by CNSC staff.

##### Environmental risk assessment

The CNSC uses environmental risk assessments (ERAs) to ensure that people and the environment are protected. With the exception of arsenic, the Cigar Lake ERA submission for 2017 indicated that contaminant levels in the receiving water and sediment were within the predictions made in the 2011 environmental assessment. However, arsenic levels in Seru Bay of Waterbury Lake remain below the Saskatchewan Surface Water Quality Objectives of 5 µg/L. CNSC staff verified that Cameco is implementing measures to address the increase in arsenic in its effluent.

The Cigar Lake environmental performance report (EPR) assesses environmental performance over a five-year period. The most recent EPR for the period 2011 to 2015 was submitted to CNSC staff in 2016. CNSC staff reviewed the environmental monitoring data including water, groundwater and sediment quality as well as health indicators for fish and their preys inhabiting sediments. CNSC staff concluded that the monitoring programs and special studies were sufficiently comprehensive and provided the required information. The models used to predict environmental performance continued to be valid.

After reviewing the EPR and ERA, CNSC staff concluded that adequate measures have been taken at the Cigar Lake Operation to protect the environment and the public.

##### Assessment and monitoring

CNSC staff confirmed that the licensee, in accordance with the Cigar Lake environmental protection program, successfully carried out required effluent and environmental monitoring, site inspections, environmental awareness training and program implementation.

Through compliance activities conducted during 2017, CNSC staff concluded that environmental monitoring conducted at the Cigar Lake Operation met regulatory requirements and treated effluent discharge complied with licence requirements. There were no exceedances of the action levels listed in the environmental code of practice.

##### Effluent and emissions control
###### Treated effluent released to the environment

CNSC staff confirmed that parameter concentrations in treated effluent were low and remained below treated-effluent discharge limits at the Cigar Lake Operation. CNSC staff verified that treated effluent released to the environment was well below regulatory requirements.

Constituents of potential concern (COPC) with potential to adversely affect the environment in treated effluent at northern Saskatchewan uranium mine and mill operations are molybdenum, selenium and uranium. At the Cigar Lake Operation throughout 2017, concentrations for these COPC (shown in figures 2.6 to 2.8) remained below their respective action levels and well below provincial licence effluent discharge limits.

The Cigar Lake Operation is also required to monitor concentrations of other regulatory contaminants and COPC, such as radium-226, arsenic, copper, lead, nickel, zinc, total suspended solids (TSS), as well as pH levels. CNSC staff reviewed and confirmed that the Cigar Lake Operation continues to meet Metal Mining Effluent Regulations (MMER) discharge limits (shown in section 2.4).

As noted earlier, the Cigar Lake Operation EPR identified an increasing arsenic trend in effluent in the year 2016. While below regulatory limits, arsenic concentrations in the treated effluent were above environmental assessment predictions and above concentrations previously measured in the effluent prior to achieving full ore production. In response, Cameco created a working group to identify causes of the elevated concentration and to develop mitigation strategies. Throughout 2017, Cameco implemented several mitigation techniques to reduce arsenic loadings to the environment, such as altering the pH profile of the treatment system to create more favourable conditions for arsenic removal. CNSC staff were satisfied that Cameco was taking appropriate actions to lower arsenic concentrations in the effluent. CNSC staff will follow-up through compliance activities in 2018.

CNSC staff will continue to review effluent quality results to ensure that effluent treatment performance remains effective.

###### Air emissions released to the environment

As required by the CNSC, the Cigar Lake Operation maintains an air and terrestrial monitoring program. Air monitoring at the Cigar Lake facility includes ambient radon, total suspended particulate (TSP), soil sampling and lichen sampling to assess the impact of air emissions. Lichen samples are analyzed to determine the level of airborne particulate contaminants deposited on the surface of the lichen as a means of estimating the level of contamination, if any, entering lichen consumers, such as caribou.

Radon in ambient air is measured using passive track-etch cups at eight monitoring stations around the operation. The background concentration of radon in northern Saskatchewan ranges from less than 7.4 Bq/m3 to 25 Bq/m3.

Figure 3.4 illustrates that the average concentrations of radon in air at the Cigar Lake Operation over the period from 2013 to 2017, showing that measured values were similar to values measured as northern Saskatchewan regional background. The average radon concentrations were less than a reference level of 55 Bq/m3, representing an incremental dose of 1 mSv per year over background. CNSC staff noted that concentrations remained well below the reference level.

A high-volume air sampler was used to collect and measure TSP in air. Results of the TSP levels were below provincial standards (see table 3.2). The mean concentrations of metal and radionuclides adsorbed to TSP were low and below the reference annual air quality levels identified in table 3.2.

Soil and terrestrial vegetation may be affected by atmospheric deposition of particulate and adsorbed metals and radionuclides associated with onsite activities. Lichen and soil samples were collected in 2016 as required by the triennial sampling program. Concentrations of COPC measured in the soil samples collected from the study area were comparable to historical results. Concentrations of metals remained below the Canadian Environmental Quality Guidelines issued by the Canadian Council of Ministers of the Environment. Radionuclide concentrations were low, and near or equal to background levels and analytical detection limits. CNSC staff concluded that the level of airborne particulate contaminants produced by the Cigar Lake Operation is acceptable and does not pose a risk to the environment.

Table 3.2: Cigar Lake Operation – Concentrations of metal and radionuclides in air, 2013–17*
Parameter Reference annual air quality level* 2013 2014 2015 2016 2017
As (µg/m3) 0.06 (1) 0.00025 0.00025 0.00031 0.0003 0.00039
Mo (µg/m3) 23 (1) 0.00021 0.0001 0.0001 0.0002 0.0002
Ni (µg/m3) 0.04 (1) 0.00104 0.00067 0.00062 0.00105 0.00103
Pb (µg/m3) 0.10 (1) 0.0007 0.0013 0.0009 0.0009 0.0008
Se (µg/m3) 1.9 (1) 0.00003 0.00003 0.00003 0.00003 0.00005
Pb210 (Bq/m3) 0.021 (2) 0.000268 0.00025 0.000315 0.000305 0.00036
Po210 (Bq/m3) 0.028 (2) 0.000074 0.000086 0.000095 0.000099 0.00012
Ra226 (Bq/m3) 0.013 (2) 0.000004 0.000008 0.000014 0.000020 0.000030
Th230 (Bq/m3) 0.0085 (2) 0.000011 0.00001 0.000014 0.000012 0.000023
U (µg/m3) 0.06 (1) 0.00007 0.00008 0.00055 0.00113 0.00151
TSP (µg/m3) 60 (3) 30.2 24.7 15.8 11.4 12.9

1 Reference annual air quality levels are derived from Ontario’s 24-hour ambient air quality criteria (2012).

2 Reference level is derived from International Commission on Radiological Protection (ICRP) Publication 96, Protecting People Against Radiation Exposure in the Event of a Radiological Attack.

3 Saskatchewan Environmental Quality Guidelines, table 20: Saskatchewan Ambient Air Quality Standards. Values are calculated as geometric means.

* Reference levels are based on Province of Ontario Ambient Air Quality Criteria and are shown for reference only. No federal or Province of Saskatchewan limits were established at the time of this report.

The lichen chemistry results from exposure stations in 2016 were similar to that of the reference stations and historic data. CNSC staff concluded that the level of airborne particulate contaminants was acceptable and did not pose a risk to lichen consumers.

##### Uncontrolled releases

In 2017, five events reported to CNSC staff were submitted as releases of hazardous substances to the environment. All five spills listed below were minor and reporting of these events met the requirements of RD/GD-99.3, Public Information and Disclosure:

• On February 22, 2017, approximately 4 kilograms of anhydrous ammonia was released into the atmosphere due to the failure of a modular freeze plant stem valve.
• On July 3, 2017, approximately 1 kilogram of anhydrous ammonia was released into the atmosphere due to a leak on the suction valve on compressor no. 4 of modular freeze plant no. 2.
• On July 26, 2017, approximately 4 kilograms of anhydrous ammonia was released into the atmosphere due to a fracture of the standby filter housing on modular freeze plant no. 1.
• On August 6, 2017, approximately 317 kilograms of anhydrous ammonia was released into the atmosphere due to a leak from the intercooler line on modular freeze plant no. 2.
• On December 6, 2017, approximately 13 kilograms of anhydrous ammonia was released into the atmosphere due to a leak from an isolation valve during a power outage.

All five events were attributed to failure of various mechanisms related to the ground-freezing operation. There were no residual impacts to the environment as a result of the releases of hazardous substances at the Cigar Lake Operation in 2017. CNSC staff were satisfied with the Cigar Lake Operation’s reporting of these spills and the corrective actions taken. CNSC staff rated all 2017 spills as “low significance”, in accordance with the definitions provided in table H-2 in appendix H of this report. Figure 2.5 in section 2 of this report displays the number of environmental reportable spills at the Cigar Lake Operation from 2013 to 2017.

Appendix H contains a brief description of the spills in 2017 and the respective significance ratings, corrective actions taken by the licensee and CNSC staff’s assessment of those actions.

##### Protection of the public

Cameco is required to demonstrate that the health and safety of the public are protected from exposures to hazardous substances released from the Cigar Lake Operation. The effluent and environmental monitoring programs currently conducted by the licensee are used to verify that releases of hazardous substances do not result in environmental concentrations that may affect public health.

The CNSC receives reports of discharges to the environment through the reporting requirements outlined in the licence and licence conditions handbook. The review of Cigar Lake Operation’s hazardous (non-radiological) discharges to the environment indicates that the public and environment are protected. CNSC staff confirmed that environmental concentrations in the vicinity of the Cigar Lake Operation remain within those predicted in the 2017 ERA, and that human health remains protected.

Based on their reviews of the Cigar Lake Operation’s programs, CNSC staff concluded that the public continued to be protected from operational emissions in 2017.

#### 3.4 Conventional health and safety

For 2017, CNSC staff continued to rate the conventional health and safety SCA as “satisfactory”.

Cigar Lake Operation – Conventional health and safety ratings
2013 2014 2015 2016 2017
FS SA SA SA SA

FS = fully satisfactory

SA = satisfactory

##### Practices

CNSC staff monitored the implementation of the Cigar Lake Operation’s safety and health management program to ensure the protection of workers. The program includes planned internal inspections, a safety permit system, occupational health committees, training and incident investigations. Cameco’s incident reporting system includes reporting, trending and investigation of near misses, which helps reduce future incidents that could cause injury.

CNSC staff noted the implementation of the Safety Through Empowering Employee Leadership Committee. This safety steering committee is unique to the Cigar Lake Operation, along with the Good Catch reporting environment in which site staff are recognized for pointing out near misses related to safety. These were found to be safety culture strengths at the Cigar Lake Operation.

CNSC staff verified that the conventional health and safety work practices and conditions at the Cigar Lake Operation continued to be effective in 2017.

##### Performance

Table 3.3 summarizes lost-time injuries (LTIs) at the Cigar Lake Operation from 2013 to 2017. There were no LTIs at the Cigar Lake Operation in 2017.

2013 2014 2015 2016 2017 4 1* 4 1 0 5.57 0.0 17.06 2.4 0 0.25 0.12* 0.56 0.14 0 1 An injury that takes place at work and results in the worker being unable to return to work for a period of time. 2 A measure of the total number of days lost to injury for every 200,000 person-hours worked at the site. Accident severity rate = [(# of days lost in last 12 months) / (# of hours worked in last 12 months)] x 200,000. 3 A measure of the number of LTIs for every 200,000 person-hours worked at the site. Accident frequency rate = [(# of injuries in last 12 months) / (# of hours worked in last 12 months)] x 200,000. * One event that occurred in 2014 was reclassified as a LTI in 2015. In the 2014 report, this number was 0.
##### Awareness

CNSC staff observed that the conventional health and safety program at the Cigar Lake Operation continued to provide education, training, tools and support to workers. CNSC staff confirmed that in 2017, Cameco implemented several initiatives as part of continuous program improvement. Cigar Lake implemented changes to the safety program, including formation of a safety steering team and safety subcommittees, based on a formal safety assessment. CNSC staff confirmed that dangerous occurrences at the operation were investigated and that corrective actions were implemented.

Through their compliance verification activities, CNSC staff concluded that the Cigar Lake Operation’s health and safety program met regulatory requirements in 2017.

### 4. McArthur River Operation

Cameco Corporation operates the McArthur River mine, which is located approximately 620 kilometres north of Saskatoon, Saskatchewan.

Facilities at the McArthur River Operation include an underground uranium mine, primary ore processing, ore slurry loading, waste management facilities, a water treatment plant, effluent storage ponds, surface freeze plants, administration offices and warehouse buildings (see figure 4.1).

High-grade uranium ore is mined, mixed with water and ground in a ball mill to form slurry, and pumped to the surface. The ore slurry is loaded into containers and transported to the Key Lake Operation for further processing.

Low-grade mineralized rock is also transported to the Key Lake facility in covered haul trucks. These materials are then blended with high-grade ore slurry to create the mill ore feed.

In October 2013, following a public hearing in La Ronge, Saskatchewan the Commission issued a 10-year licence to Cameco for the McArthur River Operation. Cameco’s licence expires on October 31, 2023.

CNSC staff confirmed that the McArthur River Operation production for 2017 remained less than the authorized annual production. Mining production data for the McArthur River Operation is provided in table 4.1.

Table 4.1: McArthur River Operation – Mining production data, 2013–17
Mining 2013 2014 2015 2016 2017
Ore tonnage1 (Mkg/year) 104.13 108.39 88.24 89.28 91.44
Average ore grade mined (% U) 7.49 7.4 8.59 7.89 7.09
Uranium mined (Mkg U/year) 7.8 8.02 7.58 7.04 6.48
Authorized annual production (Mkg U/year) 8.1 8.1 9.6 9.6 9.6
1 1 Mkg = 1,000,000 kg.

#### 4.1 Performance

The McArthur River Operation safety and control area (SCA) ratings for the five-year period of 2013 to 2017 are shown in appendix E. For 2017, CNSC staff rated all SCAs as “satisfactory”. This report focuses on the three SCAs that cover many of the key performance indicators for this operation: radiation protection, environmental protection, and conventional health and safety.

In 2017, CNSC staff carried out compliance inspections covering the SCAs of human performance management, safety analysis, conventional health and safety, environmental protection, waste management, radiation protection, and packaging and transport.

There were six instance of non-compliance identified during CNSC inspections at the McArthur River Operation in 2017. These instances of non-compliance were of low risk and related to the human performance management and radiation protection SCAs. The licensee implemented corrective actions, which were reviewed and accepted by CNSC staff. A complete list of inspections can be found in appendix B.

#### 4.2 Radiation protection

For 2017, CNSC staff continued to rate the radiation protection SCA as “satisfactory” based on regulatory oversight activities.

McArthur River Operation – Radiation protection ratings
2013 2014 2015 2016 2017
SA SA SA SA SA
SA = satisfactory
##### Radiological hazard control

Mining of high-grade uranium ore is the main source of radiological exposure at the McArthur River Operation. The contributors to effective doses to nuclear energy workers (NEWs) at the McArthur River facility were radon progeny (54%), gamma radiation (33%), long-lived radioactive dust (LLRD) (13%) and radon gas (< 1%). Gamma radiation hazards are controlled through practices related to the effective use of time, distance and shielding. Exposures to radon progeny, radon gas and LLRD are controlled through source control, ventilation, contamination control and personal protective equipment.

##### Radiation protection program performance

There were no exceedances of action levels at the McArthur River Operation in 2017.

Overall, the radiation protection program and practices at the McArthur River Operation remained effective in controlling radiological exposure to workers.

##### Application of ALARA

In 2017, the collective dose to NEWs at the McArthur River Operation was 760 person-millisieverts (p‑mSv), an approximate 17% reduction from the 2016 value of 909 p‑mSv (see figure 4.2).

Radon progeny exposures continued to trend downward due to ventilation upgrades that were completed in 2015 and enhanced administrative controls in higher risk work areas that began in 2016.

A sustained focus area at the McArthur River Operation is to keep exposures to LLRD as low as reasonably achievable (ALARA), and these exposures continued to trend downward over the past five years. The decrease in LLRD exposures in 2017 is attributed to a decrease in work on contaminated equipment and to the use of dose optimization methods (e.g., pre-cleaning prior to maintenance, use of dust suppression techniques).

##### Worker dose control

The average individual effective dose to NEWs was 0.79 mSv. The maximum individual effective dose of 5.73 mSv was assigned to an underground support worker. This compares to an average effective dose of 0.85 mSv and a maximum individual dose of 7.02 mSv in 2016. All individual effective doses were well below the annual regulatory limit of 50 mSv (as indicated in figures 2.3 and 2.4) and 100 mSv over five years.

Based on their compliance verification activities, such as site inspections, reviews of licensees’ reports, work practices, monitoring results and individual effective dose results, CNSC staff were satisfied that the radiation doses to workers continued to be effectively controlled at the McArthur River Operation during 2017.

#### 4.3 Environmental protection

For 2017, CNSC staff continued to rate the environmental protection SCA as “satisfactory” based on regulatory oversight activities. CNSC staff verified that the environmental protection program was effectively implemented and met all regulatory requirements.

McArthur River Operation – Environmental protection ratings
2013 2014 2015 2016 2017
SA SA SA SA SA
SA = satisfactory
##### Environmental management system

The environmental management system at the McArthur River Operation includes activities such as establishing annual environmental objectives, goals and targets. Cameco conducts internal audits of its environmental management program at the McArthur River Operation, as identified in its CNSC-approved management system program. Through regular compliance verification activities, CNSC staff review and assess the objectives, goals and targets.

##### Environmental risk assessment

The CNSC uses environmental risk assessments (ERAs) to ensure that people and the environment are protected (see section 2.4). The McArthur River environmental performance report (EPR) and updated ERA for 2010 to 2014 were submitted to the CNSC and the Saskatchewan Ministry of Environment in 2015. CNSC staff reviewed the submissions for compliance with applicable criteria outlined in the McArthur River licence conditions handbook (LCH). CNSC staff’s review confirmed that the environment and human health in the vicinity of the McArthur River Operation remains protected.

CNSC staff concluded that the environmental protection SCA at the McArthur River Operation met performance objectives and all applicable regulatory requirements.

##### Assessment and monitoring

In accordance with Cameco’s environmental protection program at McArthur River, audits were performed on effluent and environmental monitoring, site inspections, environmental awareness training and program implementation in 2017.

CNSC staff concluded that the McArthur River Operation’s environmental management system and monitoring programs met regulatory requirements and that the licensee complied with requirements for discharge of treated effluent. Figure 4.3 shows a discharge channel for treated effluent. There were no environmental action level exceedances during the 2013 to 2017 review period.

Following a February 29, 2012 Letter of Advice from Fisheries and Oceans Canada to Cameco Corporation, the Read Creek conveyance channel was commissioned in 2014. As a result of this change, in 2017, Cameco proposed changes to the environmental monitoring program at McArthur River, including removing sampling station 2.3 (East Boomerang Lake at previous inflow from the muskeg receiving area) and replacing it with sampling station 2.3.1 (Read Creek downstream of former station 2.3). CNSC staff reviewed the request and followed up during a compliance inspection. CNSC staff concluded that the location of sample station 2.3.1 was a suitable alternative site that sufficiently quantified the effects on water quality from the muskeg area. Figure 4.4 shows the change from sample station 2.3 to 2.3.1.

The following provides monitoring and assessment results for the McArthur River Operation.

##### Effluent and emissions control
###### Treated effluent released to the environment

CNSC staff verified that treated effluent released to the environment was below regulatory requirements and had remained stable or improved over the past five years. As discussed in section 2.4, constituents of potential concern (COPC) with potential to adversely affect the environment in treated effluent at multiple uranium mine and mill operations are molybdenum, selenium and uranium (see figures 2.6 to 2.8). Of the three COPC, molybdenum posed an elevated risk at the McArthur River Operation. In response, process changes such as pH adjustment and reagent rebalancing were implemented to reduce molybdenum concentrations in treated effluent. Reduction in concentration of molybdenum was observed in 2017, and concentrations have remained relatively stable from 2013 to 2017 as displayed in figure 2.6.

In addition to the COPC with potential to adversely impact the environment, Cameco analyzed treated effluent from the McArthur River Operation for concentrations of various other COPC such as radium-226, arsenic, copper, lead, nickel, zinc and total suspended solids (TSS), as well as pH levels. CNSC staff reviewed the effluent treatment concentrations and confirmed that, in 2017, the McArthur River Operation continued to meet Metal Mining Effluent Regulations discharge limits (see section 2.4).

The CNSC will continue to review effluent quality results to ensure that effluent treatment performance remains effective. Figure 4.5 shows a monitoring pond at the McArthur River Operation.

###### Air emissions released to the environment

The CNSC requires Cameco to maintain an air and terrestrial monitoring program at its McArthur River Operation. Air and terrestrial monitoring at the McArthur River facility includes ambient radon, total suspended particulate (TSP), soil sampling and lichen sampling to assess the impact of air emissions. An analysis of blueberry chemistry was also included to align with country food studies. Blueberry twigs are monitored to determine if soil-borne contaminants (when present) are being absorbed through the roots into the growing plant parts.

Monitoring of radon in ambient air is carried out using passive track-etch cups at 12 monitoring stations around the operation. Figure 4.6 shows that the average concentrations of radon in ambient air for 2013 to 2017 were similar to those in the past, with radon concentrations typical of the northern Saskatchewan regional background of less than 7.4 Bq/m3 to 25 Bq/m3. The average radon concentrations are less than the reference level of 55 Bq/m3, which represents an incremental dose of 1 mSv/year above background.

Two high-volume air samplers were used to collect and measure TSP in air. From the average of the two stations, the TSP levels were below the reference levels specified by provincial standards (see table 4.2). The mean concentrations of metal and radionuclides adsorbed to TSP were also low, and below the reference annual air quality levels identified in table 4.2.

Table 4.2: McArthur River – Concentrations of metal and radionuclides in air, 2013–17*
Parameter Reference annual air quality level 2013 2014 2015 2016 2017
As (µg/m3) 0.06 (1) 0.0001 0.0001 0.0001 0.0001 0.0001
Cu (µg/m3) 9.6 (1) 0.0067 0.00835 0.00513 0.0065 0.0064
Ni (µg/m3) 0.04 (1) 0.0007 0.00085 0.00067 0.0007 0.0007
Pb (µg/m3) 0.10 (1) 0.0014 0.0012 0.00118 0.0011 0.0006
Se (µg/m3) 1.9 (1) 0.00003 0.0004 0.00004 0.00004 0.00004
Zn (µg/m3) 23 (1) 0.01065 0.01225 0.00980 0.0106 0.0084
Pb210 (Bq/m3) 0.021 (2) 0.00034 0.00032 0.00032 0.0002 0.0004
Po210 (Bq/m3) 0.028 (2) 0.00010 0.00009 0.00008 0.0001 0.0001
Ra226 (Bq/m3) 0.013 (2) 0.00001 0.00002 0.00001 0.00004 0.00001
Th230 (Bq/m3) 0.0085 (2) 0.00001 0.00001 0.00002 0.0001 0.0001
U (µg/m3) 0.06 (1) 0.0005 0.0005 0.0003 0.0004 0.0003
TSP (µg/m3) 60 (3) 11.5 8.94 6.31 2.24 3.24

1Reference annual air quality levels are derived from Ontario’s 24-hour ambient air quality criteria (2012).

2Reference level is derived from International Commission of Radiological Protection (ICRP) Publication 96, Protecting People Against Radiation Exposure in the Event of a Radiological Attack.

3Saskatchewan Environmental Quality Guidelines, table 20: Saskatchewan Ambient Air Quality Standards. Values are calculated as geometric means.

*Reference levels are based on Province of Ontario Ambient Air Quality Criteria and are shown for reference only. No federal or Province of Saskatchewan limits were established at the time of this report.

Soil and terrestrial vegetation may be affected by atmospheric deposition of particulate and adsorbed metals and radionuclides associated with onsite activities. A terrestrial monitoring program is in place and includes triennial measurements of metals and radionuclides in soil and blueberry samples.

Soil and blueberry twig samples were last collected in 2015 as required by the triennial sampling program. The 2015 results indicated that parameters measured were within historical ranges. Concentrations of metals in soils remained below the Canadian Environmental Quality Guidelines set by the Canadian Council of Ministers of the Environment and radionuclide concentrations were near, or at, background levels and analytical detection limits. Triennial lichen sampling was last conducted in 2015. The results of the lichen monitoring were within historic ranges and do not suggest that COPC are accumulating in lichen tissues above background concentrations. The next lichen sampling will be conducted in 2018.

CNSC staff concluded that the level of airborne particulate contaminants produced by the McArthur River Operation is acceptable and does not pose a risk to the environment.

##### Uncontrolled releases

In 2017, there were two events reported to the CNSC that were classified as a release (spill) of a hazardous substance to the environment. These spills were minor and reporting of this event met the requirements of RD/GD-99.3, Public Information and Disclosure:

• On December 2, 2017, because of low mass released, an unknown amount of ammonia was released into the atmosphere due to leaks on freeze plant skid no. 2.
• On December 31, 2017 an unknown amount (due to low mass released) of anhydrous ammonia was released into the atmosphere due to a worn shaft seal coupling within the main freeze plant.

There were no impacts to the environment as a result of the spills and CNSC staff were satisfied with the corrective actions taken. CNSC staff rated the spills as “low significance”. Appendix H contains a brief description of the spills and corrective actions taken by the licensee, which included preventive maintenance. CNSC spill rating definitions can be found in appendix H, table H-2.

Figure 2.5 in section 2 identifies the number of spills at the McArthur River Operation from 2013 to 2017.

##### Protection of the public

Cameco is required to demonstrate that the health and safety of the public are protected from exposures to hazardous substances released from the McArthur River Operation. The effluent and environmental monitoring programs currently conducted by the licensee are used to verify that releases of hazardous substances do not result in environmental concentrations that may affect public health.

The CNSC receives reports of discharges to the environment through the reporting requirements outlined in the licence and licence conditions handbook. The review of McArthur River Operation’s hazardous (non-radiological) discharges to the environment indicates that the public and environment are protected. CNSC staff confirmed that environmental concentrations in the vicinity of the McArthur River Operation remain within those predicted in the 2017 ERA, and that human health remains protected.

Based on their reviews of the programs at McArthur River Operation, CNSC staff concluded that the public continues to be protected from operation emissions.

#### 4.4 Conventional health and safety

CNSC staff rated the conventional health and safety SCA as “satisfactory” based on regulatory oversight activities conducted during 2017.

McArthur River conventional health and safety ratings
2013 2014 2015 2016 2017
SA SA SA SA SA
SA = satisfactory
##### Practices

To promote continued effective safety performance, the McArthur River Operation has implemented a health and safety management program to identify and mitigate risks. The program includes a safety permit system, continued training, planned internal inspections, occupational health committees and incident investigations. The incident reporting system includes reporting on and investigation of near misses and reduces future incidents that could cause injury. CNSC staff verified that Cameco’s conventional health and safety work practices and conditions at the McArthur River Operation met regulatory requirements in 2017.

##### Performance

As shown in table 4.3, there was one lost-time injury (LTI) reported at the McArthur River Operation in 2017.

2013 2014 2015 2016 2017 1* 1** 0 2*** 1 0 14.6** 7.31** 0 12.11 0.11* 0.11** 0 0.24*** 0.15 1 An injury that takes place at work and results in the worker being unable to return to work for a period of time. 2 A measure of the total number of days lost to injury for every 200,000 person-hours worked at the site. Accident severity rate = [(# of days lost in last 12 months) / (# of hours worked in last 12 months)] x 200,000. 3 A measure of the number of LTIs for every 200,000 person-hours worked at the site. Accident frequency rate = [(# of injuries in last 12 months) / (# of hours worked in last 12 months)] x 200,000. * One LTI was moved from 2012 to 2013, resulting in the number of LTIs in 2012 decreasing from 2 to 1 and the number of LTIs in 2013 increasing from 0 to 1. These changes resulted in a frequency rate change from 0.2 to 0.1 in 2012 and 0 to 0.11 in 2013. ** A lifting injury in 2014 eventually required surgery in 2015, resulting in lost time. As a result, LTIs for 2014 were increased from 0 to 1, severity rate from 0 to 14.6 and frequency rate from 0 to 0.11. The 2015 severity rate was also affected due to lost time in 2015. *** A hip injury in 2016 resulted in the worker being unable to return to work in 2017, resulting in lost time. As a result 2016 LTIs increased from 1 to 2, and frequency rate from 0.12 to 0.24.

Compliance verification activities confirmed that the McArthur River Operation focuses on the prevention of accidents, reducing LTIs and the number of injuries requiring medical treatment.

On August 17, 2017 an incident resulting in the loss of the distal phalanx on the fifth digit of the left hand was verbally reported to the Commission. This incident did not result in an LTI and is not included in appendix I.

##### Awareness

CNSC staff observed that the conventional health and safety programs at the McArthur River Operation continued to provide education, training, tools and support to workers. Managers, supervisors and workers share and promote the idea that safety is the responsibility of all individuals. Site operation’s management stresses the importance of conventional health and safety through regular communication, management oversight and continual improvement of safety systems.

CNSC staff verified that the health and safety program at the McArthur River Operation met regulatory requirements.

### 5. Rabbit Lake Operation

The Rabbit Lake Operation is located 750 kilometres north of Saskatoon, Saskatchewan. Owned and operated by Cameco Corporation, the site stretches across approximately 20 kilometres (see figure 5.1). The Eagle Point underground mine is located at the northern margin of the property. Moving southward, three mined-out pits, two reclaimed, A-Zone and D-Zone, and one flooded, B-Zone pit all bordering Collins Bay of Wollaston Lake. The B-Zone pit remains isolated from Collins Bay by an intact dyke. In the central part of the property, the mined-out Rabbit Lake pit was converted to a tailings management facility (TMF). Adjacent to the in-pit TMF is the mill. South of the mill is the above ground TMF, which has not received tailings since 1985. At the southern margin, after passage through settling polishing ponds, treated effluent continuously discharges and eventually reaches Hidden Bay of Wollaston Lake.

In October 2013, the Commission issued a 10-year licence following a public hearing in La Ronge, Saskatchewan. Cameco’s licence for the Rabbit Lake Operation expires on October 31, 2023.

Mining production data for the Rabbit Lake Operation are provided in table 5.1.

Table 5.1: Rabbit Lake – Mining production data, 2013–17
Mining 2013 2014 2015 2016 2017
Ore tonnage (Mkg/year)1 255.15 328.13 309.50 79.87 0
Average ore grade mined (%U) 0.50 0.48 0.54 0.59 0
Uranium mined (Mkg U/year) 1.28 1.57 1.66 0.47 0
1 1 Mkg = 1,000,000 kg.

On April 21, 2016 Cameco formally announced that, due to market conditions, production at the Rabbit Lake Operation was to be suspended, and the facility was placed into a safe state of care and maintenance. This decision allows Cameco the flexibility to resume production when market conditions improve.

There was no uranium concentrate produced and no ore production conducted at the Rabbit Lake Operation during the 2017 reporting period. Table 5.2 provides milling production data from 2013 to 2017.

Table 5.2: Rabbit Lake Operation – Milling production data, 2013–17
Milling 2013 2014 2015 2016 2017
Mill ore feed (Mkg/year)1 334.98 386.97 313.71 61.67 0
Average annual mill feed grade (%U) 0.49 0..42 0..53 0.71 0
Percent uranium recovery 97.2 97.3 97.1 97.0 0
Uranium concentrate produced (Mkg U/year) 1.59 1.60 1.62 0.43 0
Authorized annual production (Mkg U/year) 4.25 4.25 4.25 4.25 4.25
1 1 Mkg = 1,000,000 kg.

Cameco has implemented the safe transition of operations into care and maintenance, with a focus was on three key areas: the preservation of facilities and equipment to ensure future availability; the ongoing collection and treatment of contaminated water from various areas of the operation; and the maintenance of operational compliance with applicable regulations, approvals and licensed programs.

The transition to care and maintenance relates to the suspension of production and the safe shutdown of related infrastructure and systems. The main functional areas to be maintained include mill operations, mine operations and tailings management areas. A submission updating the plan and process to be followed and the status of the facility was provided to the CNSC and the Saskatchewan Ministry of Environment in October 2016. The submission has been reviewed by both agencies and the measures and activities outlined have been accepted. The following summarizes the transition initiatives.

##### Mill operations

The mill transition to care and maintenance is similar to a routine maintenance shutdown event:

• Mill production circuits were emptied, flushed, cleaned and preserved.
• The mill ore pad was emptied of remaining ore inventory.
• The water treatment circuit was maintained and restored to normal operating status.
• Sulphuric acid inventories were maximized and operation of the acid plant was suspended.
• Mill ventilation was optimized for energy and heating use to reflect the mill circuits’ status.
• Hazardous materials were transported to other Cameco facilities or returned to the supplier.
• Inactive areas were added to routine inspection schedules, with checks conducted and documented on a regular basis.

Fire protection systems will continue to be maintained throughout the main mill complex.

##### Mine operations

During the care and maintenance period, activities at the Eagle Point mine were minimized and the focus was on continued dewatering of the mine. There is no exploration, development or production planned. Underground work consisted only of basic and required inspections and maintenance:

• All development and production work areas were made safe, and ground conditions were assessed for stability and verified by a qualified third-party evaluator.
• Inactive areas were sealed with bulkheads and mine service infrastructure was removed from these areas.
• Mine water collection and the dewatering system were simplified and centralized.
• Ventilation systems were optimized for heat and energy use.
• Mine mobile equipment was stored and preserved in ventilated locations in the mine.
• All explosives were removed from underground, and the remaining inventory was removed from the site by the vendor.
• Non-essential surface facilities were vacated and secured.

Routine inspections of the mine are conducted to ensure proper functioning of dewatering and ventilation systems and to monitor for unusual or changing conditions. Emergency response is maintained in accordance with Saskatchewan Ministry of Labour Relations and Workplace Safety requirements.

##### Tailings management

The Rabbit Lake in-pit TMF continued to operate during the care and maintenance period. The primary operating functions involved storing solids produced by the mill water treatment system; providing ongoing dewatering of tailings solids and hydraulic containment of pore water, supernatant, surface runoff and groundwater from the existing catchment area; and providing short-term water storage capacity as part of the site’s water management system. Figure 5.2 provides an aerial view of the in-pit TMF.

##### Reclamation

There have been no changes to the existing preliminary decommissioning plan and cost estimate due to the suspension of production. Progressive reclamation activities will continue throughout the care and maintenance period. Cameco must notify CNSC staff if the scope of activities or timeline for decommissioning change based on the current operating status.

CNSC staff have verified the care and maintenance status of the mine and mill and the continuation of reclamation activities through desktop reviews of applications, reports and onsite inspections. CNSC staff will continue to monitor and review the Rabbit Lake Operation’s water management practices and reclamation activities to ensure that the environment is protected during this period of care and maintenance.

#### 5.1 Performance

For 2017, CNSC staff rated all 14 safety and control areas (SCAs) as “satisfactory” based on regulatory oversight activities. Ratings at the Rabbit Lake Operation for these 14 SCAs during the five-year period of 2013 to 2017 are shown in appendix E. This report focuses on the three SCAs that cover many of the key performance indicators for mines and mills: radiation protection, environmental protection and conventional health and safety.

In 2017, CNSC staff carried out compliance inspections covering the SCAs of operating performance, fire protection, waste management and fitness for service, in addition to those for which a detailed analysis is provided in the following sections. There were four instances of non-compliance noted during CNSC inspections at the Rabbit Lake Operation for the 2017 calendar year. These instances of non-compliance were of low risk and related to the SCAs of management system and radiation protection. The licensee implemented corrective actions, which were reviewed and accepted by CNSC staff. A list of inspections is provided in appendix B.

#### 5.2 Radiation protection

For 2017, CNSC staff continued to rate the radiation protection SCA at Rabbit Lake as “satisfactory” based on regulatory oversight activities.

Rabbit Lake Operation – Radiation protection ratings
2013 2014 2015 2016 2017
SA SA SA SA SA
SA = satisfactory
##### Radiological hazard control

The sources of radiological exposure at the Rabbit Lake Operation were from mining at the Eagle Point underground mine and from milling uranium ore into yellowcake at the Rabbit Lake mill. The contributors to effective doses to nuclear energy workers (NEWs) at Rabbit Lake were radon progeny (74%), gamma radiation (19%), long-lived radioactive dust (LLRD) (5%) and radon gas (3%). Effective doses to NEWs from exposures to radon progeny, radon gas and LLRD are controlled through the effective use of source control, ventilation, contamination control and personal protective equipment (PPE). Gamma radiation exposure is controlled through practices related to the effective use of time, distance and shielding.

##### Radiation protection program performance

In 2017, CNSC staff were satisfied that the radiation protection program and practices at the Rabbit Lake Operation remained effective in controlling radiological exposure to workers. The doses to workers remained below regulatory limits and as low as reasonably achievable (ALARA). There were no exceedances of action levels reported at the Rabbit Lake Operation in 2017.

##### Application of ALARA

In 2017, the collective dose to NEWs at the Rabbit Lake Operation was 61 person‑millisieverts (p-mSv), an approximate 90% reduction from the 2016 value of 631 p‑mSv (see figure 5.3). The decrease is attributed to the suspension of production and placement of the operation into care and maintenance in 2016.

In 2017, the Rabbit Lake Operation continued to develop the program initiated in 2015 to identify and minimize areas of elevated radon progeny in the mine. Mapped radon progeny levels were used to inform the ventilation configuration during transition to care and maintenance. Radon progeny monitoring was conducted throughout the mill to ensure hazard levels continue to meet hazard objectives throughout all ventilation adjustments.

CNSC staff have verified through regulatory oversight activities that Cameco continues to maintain worker exposures ALARA.

##### Worker dose control

During 2017, the average individual effective dose for NEWs was 0.4 mSv and the maximum individual effective dose was 1.56 mSv. This compares to an average effective dose of 0.85 mSv and a maximum individual dose of 4.95 mSv in 2016. This decrease is attributed to the suspension of mining and milling as the operation transitioned into care and maintenance. As shown in section 2 and figures 2.3 and 2.4, all individual effective doses for NEWs were below the annual regulatory limit of 50 mSv and 100 mSv in five years.

Based on CNSC staff compliance verification activities such as site inspections, reviews of licensees’ reports, work practices, monitoring results and individual effective dose results for 2017, CNSC staff were satisfied that the Rabbit Lake Operation continued to be effective in controlling radiation doses to workers.

#### 5.3 Environmental protection

For 2017, CNSC staff continued to rate the environmental protection SCA at Rabbit Lake as “satisfactory” based on regulatory oversight activities. CNSC staff concluded that the licensee’s environmental protection program was effectively implemented and met all regulatory requirements.

Rabbit Lake Operation – Environmental protection ratings
2013 2013 2015 2016 2017
SA SA SA SA SA
SA = satisfactory
##### Environmental management system

Cameco’s environmental management system at Rabbit Lake is described in its CNSC approved environmental protection program and includes activities such as establishing annual environmental objectives, goals and targets. Cameco conducts internal audits of its environmental protection program at Rabbit Lake as identified in their CNSC approved management system program. Through regular compliance verification activities, CNSC staff review and assess the objectives, goals and targets.

##### Environmental risk assessment

The Rabbit Lake 2010 to 2014 Environmental Performance Report, which included an environmental and human health risk assessment, was submitted to the Saskatchewan Ministry of Environment and the CNSC in 2015. CNSC staff reviewed the submissions and concluded the monitoring programs and special studies were adequate, provided required information and contained sufficient information to complete a review. CNSC staff’s assessment confirmed the environment and human health in the vicinity of the Rabbit Lake Operation remains protected.

##### Assessment and monitoring

During 2017, CNSC staff verified that the Rabbit Lake environmental protection program was effectively implemented and met regulatory requirements.

CNSC staff concluded that Cameco’s environmental management system and monitoring programs at Rabbit Lake met regulatory requirements and all treated effluent discharged to the environment complied with licence requirements. There were no exceedances of environmental action levels at the Rabbit Lake Operation during 2017.

##### Effluent and emissions control
###### Treated effluent released to the environment

For previously identified constituents of potential concern (COPC) with the potential to adversely affect the environment (i.e., uranium, molybdenum and selenium), the effluent treatment system at the Rabbit Lake Operation continues to meet performance expectations in reducing the concentrations of these parameters (see figures 2.6 to 2.8 of section 2). Substantial water treatment modifications have been completed at the Rabbit Lake Operation since 2007 to improve the quality of the treated effluent released to the environment. The licensee installed additional chemical treatment processes to reduce molybdenum. CNSC staff verified molybdenum concentrations displayed a marked reduction from 2012 levels, were relatively consistent from 2014 to 2016 and showed a decline in 2017.

In 2006, a review titled Uranium in Effluent Treatment Process identified a concentration of uranium in effluent of 0.1 mg/L as a potential treatment design objective that could be achieved and is protective of the environment. The 2007 treatment circuit modifications have also been successful in meeting the uranium target objective of 0.1 mg/L. CNSC staff also confirmed selenium concentrations have remained consistent with previous years (figure 2.7) and showed a decline in the past three years.

Cameco also analyzed treated effluent for concentrations of various other contaminants such as radium-226, arsenic, copper, lead, nickel, zinc and total suspended solids (TSS), as well as pH levels. As shown in section 2.4, CNSC staff verified the Rabbit Lake Operation continues to meet Metal Mining Effluent Regulations discharge limits.

In 2017, the concentrations of regulated parameters in treated effluent released to the environment were well below the regulatory limits. Figure 5.4 shows the B-Zone settling pond at the Rabbit Lake Operation. CNSC staff will continue to review effluent quality results to ensure that effluent treatment performance remains effective.

###### Air emissions released to the environment

Cameco also maintains an air and terrestrial monitoring program at Rabbit Lake. Air and terrestrial monitoring at the Rabbit Lake facility includes ambient radon, total suspended particulate (TSP), sulphur dioxide, soil sampling and lichen sampling to assess the impact of air emissions.

Radon in ambient air around the Rabbit Lake Operation is monitored at 18 stations using passive track-etch cups. Figure 5.5 shows that the average concentrations of radon in ambient air for 2013 to 2017 is similar to background concentrations for northern Saskatchewan regional baseline of less than 7.4 Bq/m3 to 25 Bq/m3. The average radon concentrations are less than the reference level of 55 Bq/m3, which represents an incremental dose of 1 mSv/year above background.

Three high-volume air samplers were used to collect and measure TSP in air. The TSP levels from the average of the three stations were below the reference levels specified by provincial standards (see table 5.3). TSP samples were also analyzed for concentrations of metals and radionuclides. The mean concentrations of metals and radionuclides adsorbed to TSP are low and remained below the reference annual air quality levels identified in table 5.3.

Table 5.3: Rabbit Lake Operation – Concentrations of metal and radionuclides in air, 2013–17
Parameter Reference annual air quality level* 2013 2014 2015 2016 2017
As (µg/m3) 0.06 (1) 0.000175 0.000217 0.000207 0.000290 0.000285
Ni (µg/m3) 0.04 (1) 0.000007 0.000138 0.000192 0.000540 0.000404
Pb210 (Bq/m3) 0.021 (2) 0.000010 0.000013 0.000015 0.000011 0.000013
Ra226 (Bq/m3) 0.013 (2) 0.000002 0.000002 0.000001 0.000002 0.000004
Th230 (Bq/m3) 0.0085 (2) 0.000001 0.000003 0.000001 0.000002 0.000004
U (µg/m3) 0.06 (1) 0.001033 0.001960 0.002341 0.000899 0.000190
TSP (µg/m3) 60 (3) 7.67 6.21 6.87 4.97 4.79

1 Reference annual air quality levels are derived from Ontario’s 24-hour ambient air quality criteria (2012).

2 Reference level is from International Commission on Radiological Protection (ICRP) Publication 96.
Protecting People Against Radiation Exposure in the Event of a Radiological Attack.

3 Saskatchewan Environmental Quality Guidelines, table 20: Saskatchewan Ambient Air Quality Standards. Values are calculated as geometric means.

* Reference levels are based on Province of Ontario Ambient Air Quality Criteria and are shown for reference only. No federal or Province of Saskatchewan limits were established at the time of this report.

In 2017, Cameco started comparing air quality data from Rabbit Lake to the Province of Saskatchewan’s Ambient Air Quality Standards (table 20 of the Saskatchewan Environmental Quality Standards, June 2015). The implementation of the air quality standards in Saskatchewan was immediate for any new facility, but these standards came into effect for existing facilities when existing approvals to operate were renewed and/or revised. The new standards are shown for TSP and sulphur dioxide for the Rabbit Lake Operation, although the operation did not become subject to the new standards until February 2017.

Daily in-stack monitoring of sulphur dioxide emissions from the mill acid plant was discontinued in 2017 for the duration of the care and maintenance period, as the acid plant and mill processing circuits were not operating. When the mill acid plant is in operation, a sulphur dioxide monitoring station, located approximately 450 metres southwest of the plant, detects releases associated with mill operations. Sulphur dioxide monitoring results from 2013–17 (see figure 5.6) show that there were no exceedances of the annual standard of 20 µg/m3 when the acid plant was in operation. CNSC staff verified that ambient sulphur dioxide levels remained at safe concentrations in the nearby environment during this time period.

Soil and terrestrial vegetation may be affected by the atmospheric deposition of particulate and adsorbed metals and radionuclides associated with onsite activities. A terrestrial monitoring program is in place and includes measurements of metals and radionuclides in lichen.

Lichen sampling has been conducted for three decades at the Rabbit Lake Operation, and most recently in 2013. The next sampling is scheduled for 2019. CNSC staff concluded that the level of airborne particulate contaminants produced by the Rabbit Lake Operation does not pose a risk to lichen consumers, such as caribou.

##### Uncontrolled releases

In 2017, one event was reported to CNSC staff as a release (spill) of hazardous substances to the environment. The spill was minor and there were no residual impacts on the environment. The licensee’s report of this event met the requirements of RD/GD‑99.3, Public Information and Disclosure:

• On December 3, 2017, an unknown quantity of propane was released into the atmosphere at the camp due to a broken seal on a threaded fitting on a propane gas line. It was estimated that approximately 17 litres of liquid propane was released over a period of 10 minutes.

Appendix H provides a brief description of the spill and actions taken by the licensee. CNSC staff reviewed the corrective actions taken by the licensee and found them to be acceptable. CNSC staff rated the 2017 spill as “low significance” in accordance with the definitions provided in table H-2, appendix H of this report.

Figure 2.5 displays the number of environmental reportable spills from 2013 to 2017 at the Rabbit Lake Operation.

##### Protection of the public

Cameco is required to demonstrate that the health and safety of the public are protected from exposures to hazardous substances released from the Rabbit Lake Operation. The effluent and environmental monitoring programs currently conducted by the licensee are used to verify that releases of hazardous substances do not result in environmental concentrations that may affect public health.

The CNSC receives reports of discharges to the environment through the reporting requirements outlined in the licence and licence conditions handbook. The review of Rabbit Lake Operation’s hazardous (non-radiological) discharges to the environment indicates that the public and environment are protected. CNSC staff confirmed that environmental concentrations in the vicinity of the Rabbit Lake Operation remained within those predicted in the 2017 ERA, and that human health remained protected in 2017.

Based on their reviews of the programs at the Rabbit Lake Operation, CNSC staff concluded that the public continued to be protected from operational emissions in 2017.

#### 5.4 Conventional health and safety

For 2017, CNSC staff continued to rate the conventional health and safety SCA as “satisfactory” based on regulatory oversight activities.

Rabbit Lake Operation – Conventional health and safety ratings
2013 2014 2015 2016 2017
SA SA SA SA SA
SA = satisfactory
##### Practices

Cameco’s Rabbit Lake Operation has implemented a safety and health management program to identify and mitigate risks. The program includes internal inspections, a safety permit system, occupational health committees, training and incident investigations. CNSC staff monitor this program through compliance activities to ensure the protection of workers.

The incident reporting system at the Rabbit Lake Operation includes reporting on and investigating near misses, with the aim of reducing future incidents that could cause injury. CNSC compliance verification activities confirmed the Rabbit Lake Operation continued to focus on the prevention of accidents and injuries through the implementation of its health and safety management program.

##### Performance

There were no lost-time injuries (LTIs) reported for the Rabbit Lake Operation in 2017. Table 5.4 shows LTI statistics for the Rabbit Lake Operation from 2013 to 2017.

2013 2014 2015 2016 2017 0 1 2 1 0 25.8 11.4 55.3 2.65 0 0.0 0.15 0.33 0.27 0 1 An injury that takes place at work and results in the worker being unable to return to work for a period of time. 2 A measure of the total number of days lost to injury for every 200,000 person-hours worked at the site. Accident severity rate = [(# of days lost in last 12 months) / (# of hours worked in last 12 months)] x 200,000. 3 A measure of the number of LTIs for every 200,000 person-hours worked at the site. Accident frequency rate = [(# of injuries in last 12 months) / (# of hours worked in last 12 months)] x 200,000.
##### Awareness

CNSC staff observed that Cameco’s conventional health and safety program at the Rabbit Lake Operation continued to provide education, training, tools and support to workers. Managers, supervisors and workers share and promote the idea that safety is the responsibility of all individuals. Site management emphasizes the importance of conventional health and safety through regular communication, management oversight and continual improvement of safety systems.

CNSC staff verified that the conventional health and safety program at the Rabbit Lake Operation remained effective in managing health and safety risks in 2017.

### 6. Key Lake Operation

Located approximately 570 kilometres north of Saskatoon, Saskatchewan, the Key Lake Operation is owned and operated by Cameco Corporation. The operation began with two open-pit mines and a mill complex. The Gaertner open pit was mined from 1983 to 1987, followed by the Deilmann open pit until 1997.

Milling of the stockpiled Deilmann ore continued until 1999, when the McArthur River Operation began supplying ore slurry to the Key Lake mill. The Key Lake Operation continues today as a mill operation that processes McArthur River ore slurry and residual special waste from previous mining at Key Lake.

After open-pit mining in the eastern pit of the Deilmann orebody was completed in 1995, the pit was converted into the engineered Deilmann tailings management facility (TMF), while mining continued in other parts of the pit area (see figure 6.2). Mill tailings continue to be deposited into this facility today.

In October 2013, the Commission issued a 10-year licence following a public hearing in La Ronge, Saskatchewan. The Key Lake Operation licence expires on October 31, 2023.

CNSC staff confirmed that production from 2013–17 at the Key Lake Operation did not exceed the authorized annual production limits. Table 6.1 presents milling data for the Key Lake Operation for this five-year reporting period.

Table 6.1: Key Lake Operation – Milling production data, 2013–17
Milling 2013 2014 2015 2016 2017
Mill ore feed (Mkg/year)1 184.10 173.01 165.56 155.30 143.26
Average annual mill feed grade (% U) 4.23 4.29 4.47 4.51 4.37
Percentage of uranium recovery 99.3 99.4 99.35 99.04 99.05
Uranium concentrate produced (Mkg U/year) 7.74 7.37 7.35 6.95 6.20
Authorized annual production (Mkg U/year) 7.85 9.60 9.60 9.60 9.60
1 1 Mkg = 1,000,000 kg.

As reported in October 2016 in Commission member document, CMD 16-M49, Cameco constructed and began commissioning a new calciner. During the commissioning process, it was determined that the new calciner would not operate as designed. During initial commissioning of the calciner, excessive corrosion was noted. Use of the new calciner ceased and an investigation was undertaken to determine the cause of the corrosion and the next steps. Cameco continued to use the existing calciner throughout 2016 and 2017. The shaft and associated brickwork for the existing calciner were replaced during the 2017 summer maintenance shutdown, and it is expected that this calciner will operate for the foreseeable future.

Cameco continues to investigate options for modifying or replacing the new calciner. Through regular compliance activities, CNSC staff verified that the existing calciner was operating safely.

#### 6.1 Performance

The Key Lake Operation’s safety and control area (SCA) ratings for the five-year period from 2013 to 2017 are shown in appendix E. CNSC staff continued to rate all SCAs for 2017 as “satisfactory” based on regulatory oversight activities. This report focuses on the three SCAs that cover many of the key performance indicators for these uranium mine and mill operations: radiation protection, environmental protection and conventional health and safety.

In 2017, CNSC staff carried out compliance inspections covering the SCAs of management system, fitness for service, conventional health and safety, radiation protection and packaging and transport, in addition to a general inspection that included multiple SCAs. There were nine instances of non-compliance noted during CNSC inspections at the Key Lake Operation for the 2017 calendar year. These instances of non-compliance were of low risk and related to the SCAs of management system, fitness for service, and radiation protection. The licensee has implemented corrective actions, which have been reviewed and accepted by CNSC staff. A list of inspections can be found in appendix B.

#### 6.2 Radiation protection

Based on regulatory oversight activities during the reporting period, CNSC staff rated the radiation protection SCA at Key Lake as “satisfactory”.

Key Lake Operation – Radiation protection ratings
2013 2014 2015 2016 2017
SA SA SA SA SA
SA = satisfactory
##### Radiological hazard control

The contributors to effective doses to nuclear energy workers (NEWs) at the Key Lake mill were gamma radiation (44%), radon progeny (34%) and long‑lived radioactive dust (LLRD) (22%). Gamma radiation hazards are controlled through practices related to the effective use of time, distance and shielding. Exposures to radon progeny and LLRD are controlled through source control, ventilation contamination control and personal protective equipment.

##### Radiation protection program performance

In 2017 there were no exceedances of action levels at the Key Lake Operation.

Overall, the radiation protection program and practices at the Key Lake Operation remained effective in controlling radiological exposure to workers.

##### Application of ALARA

In 2017, the collective dose to NEWs at the Key Lake Operation was 451 person‑millisieverts (p-mSv), a 14% reduction from the 2016 value of 522 p-mSv (see figure 6.3).

Cameco continued to meet its objectives in 2017 for keeping doses as low as reasonably achievable (ALARA) at Key Lake. Efforts include the High-5 program, which was initiated in 2010 and seeks opportunities to lower doses by providing enhanced reviews of exposures for the five employees and five contractors with the highest quarterly effective doses. Site radiation awareness activities also were performed throughout 2017: Radiation information related to incidents, events, trends, and changes to work instructions and radiation policy were shared with contractors and Cameco workers. The radiation protection department shared information through safety meetings, fact sheets, safety inspections and job task observations. CNSC staff concluded that the Key Lake radiation protection program remained effective in ensuring that worker exposures remained ALARA in 2017.

##### Worker dose control

In 2017, the average individual effective dose to NEWs was 0.66 mSv, while the maximum individual effective dose received was 5.39 mSv. This compares to an average effective dose of 0.62 mSv and a maximum individual dose of 5.37 mSv in 2016.

The maximum individual effective dose at the Key Lake Operation was identified in a mill operations worker who worked a large fraction of the year in the leaching circuit. No worker exceeded the regulatory individual effective dose limit of 50 mSv in one year and 100 mSv in a five-year dosimetry period.

Based on their compliance verification activities, such as onsite inspections, reviews of licensee reports, work practices, monitoring results and individual effective dose results, CNSC staff were satisfied that the Key Lake Operation continued to be effective in controlling radiation doses to workers in 2017.

#### 6.3 Environmental protection

For 2017, CNSC staff continued to rate the environmental protection SCA as “satisfactory” based on regulatory oversight activities. CNSC staff concluded that the licensee’s environmental protection program was effectively implemented and met all regulatory requirements.

Key Lake Operation – Environmental protection ratings
2013 2014 2015 2016 2017
SA SA SA SA SA
SA = satisfactory
##### Environmental management system

Cameco’s environmental management system at the Key Lake Operation includes activities such as establishing annual environmental objectives, goals and targets. Cameco conducts internal audits of its environmental protection program at Key Lake as identified in its CNSC-approved management system program. Through regular compliance verification activities, CNSC staff review and assess objectives, goals and targets.

##### Environmental risk assessment

In 2015, the Key Lake environmental performance report (EPR) for the 2010 to 2014 period was submitted to CNSC and Saskatchewan Ministry of Environment staff. CNSC staff reviewed the EPR and found it contained sufficient information to complete a review of the environmental performance of the Key Lake Operation from 2010 to 2014 relative to predictions in the 2013 environmental risk assessment (ERA) for the Key Lake extension project. The monitoring programs and special studies were sufficiently comprehensive and provided the required information. The models used to predict environmental performance continued to be valid. Therefore, CNSC staff confirmed the environment and human health in the vicinity of the Key Lake Operation remained protected. Additional information on the ERA is also provided in section 2.4 of this report.

##### Assessment and monitoring

Effluent and environmental monitoring, site inspections, environmental awareness training and program implementation audits were performed in accordance with Cameco’s environmental protection program at the Key Lake Operation.

CNSC staff concluded that Cameco’s environmental management system and monitoring programs at Key Lake met regulatory requirements and that the licensee complied with requirements for discharge of treated effluent. There were no exceedances of environmental action levels during the 2017 review period.

The following provides monitoring and assessment results for the Key Lake Operation.

##### Effluent and emissions control
###### Treated effluent released to the environment

At the Key Lake Operation, two effluent streams are processed in separate treatment facilities before being released to the environment:

• The mill effluent is processed with a treatment system of chemical precipitation and liquid/solid separation, and then released to Wolf Lake in the David Creek system.
• Effluent from dewatering wells of the Gaertner pit and Deilmann pit hydraulic containment systems is treated with a reverse osmosis system. The effluent is then released to Horsefly Lake in the McDonald Lake system.

The McDonald Lake system receives effluent from the reverse osmosis plant. Monitoring confirms that this effluent is within design specifications and predictions outlined in the ERA. In August 2017, Cameco submitted the Key Lake 2016 McDonald Creek Drainage Environmental Monitoring Program report. The program included the collection and analysis of water, sediment and fish tissue as well as benthic invertebrate community and fish population monitoring. Overall, the results of the 2016 program indicated that sediment and water quality and fish chemistry were similar to previous monitoring years. These results also showed little change to the benthic invertebrate community composition, density, taxon richness, biomass, and Simpson’s index for diversity and evenness.

The treated effluent quality discussed in this report refers only to the mill effluent as released to the David Creek system. CNSC staff verified that the concentration of all regulated contaminants in the treated mill effluent released in 2017 was within licence limits. There were no exceedances of environmental action levels at the Key Lake Operation.

As discussed in section 2.4, constituents of potential concern (COPC) with potential to adversely affect the environment in treated effluent at uranium mine and mill operations are molybdenum, selenium and uranium (see figures 2.6 to 2.8). Of these, molybdenum and selenium concentrations were of primary concern at the Key Lake Operation. The licensee has therefore made targeted changes to processes, in order to reduce concentrations in treated effluent.

Reductions of molybdenum and selenium occurred from 2008 to 2009 when additional treatment components were installed and optimized. Figures 2.6 and 2.7 show stable concentrations of molybdenum and selenium in treated effluent from 2013 to 2017, indicating that these parameters are being effectively controlled. Figure 2.8 indicates that uranium concentrations in treated effluent released from the Key Lake mill remained low from 2013 to 2017 and are also being effectively controlled.

In addition to the COPC, Cameco also analyzed treated effluent for concentrations of other COPC such as radium-226, arsenic, copper, lead, nickel, zinc and total suspended solids (TSS), as well as pH levels at Key Lake. As discussed in section 2.4, the Key Lake Operation continued to meet Metal Mining Effluent Regulations discharge limits.

CNSC staff will continue to review effluent quality results to ensure that treatment of effluent remains effective.

###### Air emissions released to the environment

The air and terrestrial monitoring program at the Key Lake Operation includes ambient monitoring for sulphur dioxide, radon and total suspended particulate (TSP) as well as soil and lichen sampling to assess air quality. Air emissions monitoring from the mill stacks are also included in the air-quality monitoring program.

The Key Lake calciner stack is monitored annually; the most recent stack test was completed in June 2017. The stack emission results were within historical ranges and verified that operational controls are working as designed. Sulphur dioxide concentrations from the acid plant stack are monitored daily. Concentrations are consistent with those reported since the commissioning of the new acid plant in 2012.

Radon in air around the Key Lake Operation is monitored at five stations using passive track-etch cups. Figure 6.4 shows the average concentrations of radon in ambient air for 2013 to 2017. Ambient radon concentrations were typical of the northern Saskatchewan regional background of less than 7.4 Bq/m3 to 25 Bq/m3. The measured radon concentrations are also below a reference radon concentration of 55 Bq/m3, which is equal to an incremental dose of 1 mSv per year above background.

Five high-volume air samplers were used to collect and measure TSP. The TSP levels are below the province of Saskatchewan’s authorized concentration of contaminants monitored for ambient air quality, as listed in the facility’s approval to operate pollutant control facilities. TSP samples are also analyzed for concentrations of metals and radionuclides. The mean concentrations of metal and radionuclides adsorbed to TSP are low and below the reference annual air quality levels as identified in table 6.2.

Table 6.2: Key Lake Operation – Concentrations of metal and radionuclides in air, 2013–17
Parameter Reference annual air quality level* 2013 2014 2015 2016 2017
As (µg/m3) 0.06 (1) 0.00166 0.00444 0.0016 0.0010 0.0045
Ni (µg/m3) 0.04 (1) 0.00118 0.00340 0.0013 0.0007 0.0029
Pb210 (Bq/m3) 0.021 (2) 0.00032 0.00044 0.0003 0.0003 0.0004
Ra226 (Bq/m3) 0.013 (2) 0.00010 0.00022 0.0001 0.0001 0.0003
Th230 (Bq/m3) 0.0085 (2) 0.00010 0.00022 0.0001 0.0001 0.0002
U (µg/m3) 0.06 (1) 0.00656 0.00794 0.0080 0.0076 0.0091
TSP (µg/m3) 60 (3) 14.07 15.10 13.77 10.77 11.90

1 Reference annual air quality levels are derived from Ontario’s 24-hour ambient air quality criteria (2012).

2 Reference level is derived from International Commission on Radiological Protection (ICRP) Publication 96. Protection People Against Radiation Exposure in the Event of a Radiological Attack.

3 Saskatchewan Environmental Quality Guidelines, table 20: Saskatchewan Ambient Air Quality Standards. Values are calculated as geometric means. The current air quality standard for Key Lake Operation is 70 µg/m3. The new Province of Saskatchwan standard will apply to the Key Lake Operation once the existing provincial approval is renewed or revised.

* Reference levels are based on Province of Ontario Ambient Air Quality Criteria and are shown for reference only. No federal or Province of Saskatchewan limits were established at the time of this report.

A sulphur dioxide monitor, located approximately 300 metres downwind of the mill facility, is used to continuously measure the ambient sulphur dioxide associated with mill emissions. The measured sulphur dioxide monitoring data (see figure 6.5) show no exceedances of the annual standard of 20 µg/m3 in 2017. The current air quality standard for Key Lake is 30 µg/m3, but the new standard of 20 µg/m3 will apply when the operation’s existing provincial permit is renewed or revised.

There was a substantial decline in sulphur dioxide emissions due to construction of a new acid plant in 2012. These lower emissions have been maintained throughout 2013 to 2017. In 2016, there was a decline in acid production compared to past years. The concentrations recorded at the ambient monitoring station, which are directly impacted by weather conditions, showed a notable decline and these lower concentrations were observed again in 2017.

In addition to ambient air monitoring for sulphur dioxide, sulphate levels have been monitored in four lakes to measure the effects of sulphur dioxide emissions from the operation. The results of the 2017 lake sampling program continued to show that sulphate concentrations remain relatively unchanged from historical concentrations. CNSC staff concluded that the operations at Key Lake, and the resulting sulphur dioxide emissions, do not have an adverse effect on the sulphate levels in nearby lakes.

Soil and terrestrial vegetation may be affected by atmospheric deposition of particulate, adsorbed metals and radionuclides associated with onsite activities. The terrestrial monitoring program in place includes measurements of metals and radionuclides in soil and in lichen. Lichen and soil samples were collected in 2016 as required by the triennial sampling program.

Lichen samples were collected and analyzed from five monitoring stations around the operation. Exposure stations were within the regional historical ranges for each parameter, with the exception of Wheeler River. Results from one station indicated elevated concentrations of some metals and radionuclides compared to previous years. This station will continue to be monitored to determine the cause of the elevated concentrations.

CNSC staff assessed and concluded that the level of airborne particulate contaminants produced by the Key Lake Operation is acceptable and does not pose a risk to lichen consumers, such as caribou.

Soil samples were taken in the immediate vicinity of the mine. The soil metal parameter concentrations were below the Canadian Environmental Quality Guidelines set by the Canadian Council of Ministers of the Environment. Radionuclide concentrations in soils were low and near or at background levels and analytical detection limits. The concentrations of radionuclides and metals in 2016 were consistent with previous sampling results.

Based on soil sampling results, CNSC staff concluded that the level of airborne particulate contaminants produced by the Key Lake Operation is acceptable and does not pose a risk to the environment.

##### Uncontrolled releases

In 2017, three events reported to CNSC staff were considered to be releases of hazardous substances to the environment:

• On April 15, 2017, approximately 130 kilograms of low-grade ore was released from a front‑end loader bucket on the site road and on the mine shop parking lot.
• On June 24, 2017, anhydrous ammonia was released from piping on ammonia storage tank no. 2. The leak was intermittent and no liquid ammonia was observed near the piping. The volume released could not be estimated due to the intermittent nature of the leak.
• On December 8, 2017, anhydrous ammonia was released from a flange on a section of piping used for off-loading into ammonia storage tank no. 3. The volume released could not be estimated due to the intermittent nature of the leak.

These spills were minor and reporting met the requirements of RD/GD-99.3, Public Information and Disclosure.

Appendix H provides a brief description of each spill and the actions taken by the licensee. The spills were remediated with no residual impact on the environment. The corrective actions were reviewed and found acceptable by CNSC staff. CNSC staff rated the 2017 spills at the Key Lake Operation as “low significance” as defined in table H-2, appendix H.

In follow-up to the ammonia releases, Cameco initiated a three-year staged project to refurbish the existing tanks and associated infrastructure at Key Lake. In 2018, work on ammonia tank no. 1 will include internal and external inspections of the tank, insulation and cladding replacement, replacement of electrical and instrumentation components, and replacement of existing tank valves. Additional isolation valves will also be added to the vaporizers. This project will bring the ammonia tank system, which is at least 30 years old, to current standard and address any tank corrosion and valving/piping concerns. As part of the staged project, tanks no. 2 and no. 3 will be refurbished in 2019 and 2020, respectively.

Figure 2.5 in section 2 displays the number of environmental reportable spills as well as the number of releases of hazardous material to the environment from the licensed activities at the Key Lake Operation from 2013 to 2017.

##### Protection of the public

Cameco is required to demonstrate that the health and safety of the public are protected from exposures to hazardous substances released from the Key Lake Operation. The effluent and environmental monitoring programs currently conducted by the licensee are used to verify that releases of hazardous substances do not result in environmental concentrations that may affect public health.

The CNSC receives reports of discharges to the environment through the reporting requirements outlined in the Key Lake licence and licence conditions handbook. Review of the hazardous (non‑radiological) discharges to the environment indicates that the public and environment are protected. CNSC staff confirmed that environmental concentrations in the vicinity of the Key Lake Operation remained within those predicted in the 2013 ERA and that human health remained protected in 2017.

Based on their reviews of the programs at the Key Lake Operation, CNSC staff concluded that the public continued to be protected from operational emissions in 2017.

#### 6.4 Conventional health and safety

For 2017, CNSC staff continued to rate the conventional health and safety SCA as “satisfactory” based on regulatory oversight activities.

Key Lake Operation – Conventional health and safety ratings
2013 2014 2015 2016 2017
SA SA SA SA SA
SA = satisfactory
##### Practices

Throughout 2017, CNSC staff monitored the implementation of the Key Lake Operation’s operational health and safety program and concluded that this program continues to be effective.

The Key Lake Operation’s incident reporting system records health and safety‑related events and uses several layers of review in investigations. Corrective measures are tracked and assessed for effectiveness prior to closure. The Key Lake Operation continued its planned health and safety inspection program in 2017. Any items of concern found during these inspections are included in the licensee’s incident reporting system.

##### Performance

There were two lost-time injuries (LTIs) at the Key Lake Operation between 2013 and 2017 (see table 6.3). There were no LTIs in 2017.

2013 2014 2015 2016 2017 0 0 0 2 0 8.5 0 0 71.0 0 0.0 0 0 0.41 0 1 An injury that takes place at work and results in the worker being unable to return to work for a period of time. 2 A measure of the total number of days lost to injury for every 200,000 person-hours worked at the site. Accident severity rate = [(# of days lost in last 12 months) / (# of hours worked in last 12 months)] x 200,000. 3 A measure OF the number of LTIs for every 200,000 person-hours worked at the site. Accident frequency rate = [(# of injuries in last 12 months) / (# of hours worked in last 12 months)] x 200,000.
##### Awareness

CNSC staff observed that Cameco’s conventional health and safety programs at Key Lake continued to provide education, training, tools and support to workers. The idea that safety is the responsibility of all individuals is promoted by managers, supervisors and workers. Site management stresses the importance of conventional health and safety through regular communication, management oversight and continual improvement of safety systems.

CNSC staff compliance verification activities concluded that Cameco’s health and safety program at the Key Lake Operation met regulatory requirements in 2017.

### 7. McClean Lake Operation

AREVA Resources Canada Inc. (AREVA), now known as Orano Canada Inc. (Orano) is the operator of the McClean Lake Operation. The McClean Lake Operation is a uranium mine and mill facility located approximately 750 kilometers north of Saskatoon in the Athabasca Basin of northern Saskatchewan. Ownership of the McClean Lake Operation is comprised of AREVA (70%), Denison Mines Inc. (22.5%), and Overseas Uranium Resources Development Canada Co., Ltd. (7.5%). The McClean Lake Operation includes the John Everett Bates (JEB) milling area, Sue mining area, tailings management facility (TMF), and the undeveloped McClean, Midwest and Caribou ore deposits. An aerial facility overview is shown in figures 7.1 and 7.2.

In 1996, an operating licence was first issued to the McClean Lake Operation by the Atomic Energy Control Board, predecessor of the CNSC. Since then, the operating licence has been renewed several times. Following a public hearing held on June 7 and 8, 2017 in La Ronge, Saskatchewan the Commission issued a 10-year licence to authorize AREVA to continue to operate the McClean Lake Operation. The current operating licence was renewed on July 1, 2017 and expires on June 30, 2027. This licence authorized the operation of a nuclear facility for the mining of uranium ore, the processing of high-grade ore slurry from Cameco Corporation’s Cigar Lake mine, the production of uranium concentrate, and the disposal of tailings at the TMF.

Construction of the McClean Lake Operation began in 1994. Milling of ore and processing of yellowcake product began in 1999. The McClean Lake Operation was designed and constructed with radiation protection features (e.g., lead shielding, concrete enclosures and lined leach tanks) for processing of undiluted high-grade ore averaging from 20% uranium to as high as 30% uranium. Mining and milling of uranium ore from five open-pit mines has been completed and conventional mining has not been carried out at the McClean Lake Operation since 2008. Mill tailings have been deposited in the TMF, which was engineered from the mined-out John Everett Bates (JEB) open pit.

In July 2010, processing of ore at the McClean Lake Operation was suspended and the mill was temporarily shut down, due to a shortage of ore. Shipments of high-grade ore slurry from Cameco’s Cigar Lake mine began in March 2014, and the McClean Lake Operation restarted in September 2014. After the restart and commissioning of the McClean Lake Operation with Cigar Lake ore slurry, CNSC staff focused their oversight activities on the implementation of the licensee’s radiation protection program. CNSC staff verified that the McClean Lake Operation continued to keep worker doses as low as reasonably achievable (ALARA) while processing high-grade ore at higher production levels. CNSC staff also confirmed that the licensee’s environmental management system continued to protect the environment and meet environmental performance objectives for the McClean Lake Operation.

CNSC staff confirmed the McClean Lake Operation production did not exceed the authorized annual production limit. Table 7.1 presents milling production data for the McClean Lake Operation for the five-year reporting period.

Table 7.1: McClean Lake Operation – Milling production data, 2013–17
Milling 2013 2014 2015 2016 2017
Mill ore feed1 (Mkg/year) No milling* 7.83 25.52 37.20 36.35
Average annual mill feed grade (%U) No milling* 3.00 17.56 18.08 19.3
Percentage of uranium recovery (%) No milling* 97.54 98.99 99.10 99.03
Uranium concentrate produced (Mkg U) No milling* 0.200 4.30 6.67 6.93
Authorized annual production (Mkg U/year) 5.00 5.00 5.00 9.23 9.23

1 1 Mkg = 1,000,000 kg.

* McClean Lake mill temporarily stopped producing uranium concentrate from July 2010 to September 2014.

• In April 2010, AREVA submitted an application to the CNSC requesting approval for the JEB TMF Optimization Project. CNSC staff reviewed the application and approved the project in September 2010. A two-phase plan was proposed and stage 1 of the project was completed in 2012–13 (re-sloping of TMF to a 1V:1.5H:1 slope; placement of manufactured soil bentonite liner; and placement of rip-rap protection). In 2017, AREVA continued working on removal of infrastructure impacting stage 2 re-sloping work and completed the following projects: relocation
• tailings pipe bench relocation
• decommissioning of the JEB TMF infrastructure.
• contaminated landfill AREVA plans to complete stage 2 of the JEB TMF Optimization Project in summer 2018. This will involve re-sloping of the current TMF slope to a 1V:3H slope, placement of liner to the final elevation of 443 metres above sea level, and placement of rip-rap protection.

In June 2016, AREVA submitted an application to expand the JEB TMF. AREVA expects to generate approximately 2.4 million cubic metres of tailings over the next 18 years of operation. The TMF expansion would provide additional required tailings storage capacity during continued operation of the McClean Lake mill. The JEB TMF expansion application was accepted by CNSC staff and presented to the Commission as part of the 2017 licence renewal. AREVA indicated the construction activities for the JEB TMF expansion would begin in either 2019 or 2020.

CNSC staff will continue to monitor progress through ongoing compliance activities.

#### 7.1 Performance

Ratings for all 14 safety and control areas (SCAs) for the five-year period from 2013 to 2017 are shown in appendix E. For 2017, CNSC staff continued to rate all SCAs as “satisfactory” based on regulatory oversight activities, with the exception of radiation protection, which was rated as “fully satisfactory” (see section 7.2). This report focuses on the three SCAs that cover many of the key performance indicators for this operation: radiation protection, environmental protection and conventional health and safety.

In 2017, CNSC staff carried out focused compliance inspections covering the SCAs of radiation protection, fitness for service and physical design, in addition to general inspections that included multiple SCAs. There were three instances of non-compliance noted during CNSC inspections at the McClean Lake Operation for the 2017 calendar year. These instances of non-compliance were of low risk and related to the management system and fitness for service SCAs. The licensee implemented corrective actions, which were reviewed and accepted by CNSC staff. A list of inspections can be found in appendix B.

As part of the McClean Lake Operation’s July 2017 licence renewal, CNSC staff added references to the following regulatory documents in the licence conditions handbook:

• REGDOC-2.2.2, Human Performance Management, Personnel Training
• REGDOC-2.10.1, Nuclear Emergency Preparedness and Response
• REGDOC-2.12.3, Security of Nuclear Substances: Sealed Sources

CNSC staff will continue to monitor the implementation of the requirements stated in these regulatory documents, through regulatory oversight activities that include onsite inspections and desktop reviews.

#### 7.2 Radiation protection

From 2013 to 2016, CNSC staff continued to rate the radiation protection SCA at the McClean Lake Operation as “satisfactory”. In 2017, the CNSC changed the rating to “fully satisfactory” based on the results of compliance inspections, desktop reviews and the determination that radiological hazard control, worker dose control and ALARA programs were highly effective.

McClean Lake Operation – Radiation protection ratings
2013 2014 2015 2016 2017
SA SA SA SA FS
FS = fully satisfactory SA = satisfactory
##### Radiological hazard control

The source of radiological exposure at the McClean Lake Operation is the milling of high-grade uranium ore received from Cameco’s Cigar Lake mine. The three primary contributors to dose are gamma radiation (40%), radon progeny (RnP) (33%) and long-lived radioactive dust (LLRD) (27%). Gamma radiation hazards are controlled through practices related to the effective use of time, distance and shielding. Effective doses to nuclear energy workers (NEWs) from exposures to radon progeny and LLRD are controlled through the effective use of source control, ventilation, contamination control and personal protective equipment (PPE).

AREVA has incorporated specific radiation protection features into its design to process undiluted, high-grade uranium ore at McClean Lake. These design features were established to limit radiological hazards (for all types) to specific design hazard objectives. AREVA continues to implement a comprehensive monitoring program for all hazards to confirm that these design hazard objectives are met, and to identify opportunities for improvement at the McClean Lake Operation.

Despite a slight increase in uranium feed grade and an approximate 4% production increase in 2017, gamma monitoring results remained consistent with 2016 results. However, in 2017 a reduction in hazard levels was observed for both RnP and LLRD.

CNSC staff concluded that AREVA continues to implement a comprehensive monitoring program and that this program was highly effective in controlling all radiological hazards at McClean Lake in 2017.

##### Radiation protection program performance

In 2017, there were no exceedances of action levels at the McClean Lake Operation.

The radiation protection program and practices continued to effectively maintain worker doses ALARA.

##### Application of ALARA

In 2017, despite an approximate 4% production increase, collective dose to NEWs at the McClean Lake Operation was 307 person-millisieverts (p-mSv), a 42% decrease from the 2016 value of 529 p‑mSv (see figure 7.3). This decrease in exposure was mainly due to a reduction in contract work.

In 2017, the collective dose for contract workers was approximately 11 p-mSv compared to 152 p-mSv in 2016. However, dose reductions were not limited to contract workers. Specifically, collective dose fell approximately 21% in non-contract staff (from 377 p-mSv in 2016 to 296 p-mSv in 2017).

The collective dose values are a reflection of new and existing ALARA initiatives that were implemented at the McClean Lake Operation. These include, but are not limited to:

• cleaning or flushing of equipment prior to maintenance activities
• implementing shielding material during maintenance activities
• relocation and redesign of the calciner/packaging PPE donning/doffing station
• reprogramming of slurry tote wash cycle to eliminate manual tote cleaning
• relocation of the metallurgical laboratory storage sea-can to a lower occupancy area
• enhanced PPE requirements for slurry-receiving pachuca enclosure

Through reviews of radiation monitoring and exposure reports as well as inspections, CNSC staff confirmed that the radiation protection program was highly effective and that the program ensured that worker exposures remained ALARA in 2017.

##### Worker dose control

The average individual effective dose to NEWs in 2017 was 0.91 mSv, while the maximum individual effective dose received by a NEW (a mill worker) was 5.12 mSv. These values compare to an average individual effective dose of 1.04 mSv and a maximum individual dose of 6.94 mSv in 2016. All individual effective doses were well below the annual regulatory limit of 50 mSv and 100 mSv in a five-year dosimetry period.

In 2017, more challenging dose targets were established for workers in higher dose categories. Specifically, average dose targets were set for the 10 NEWs with the highest:

• overall doses
• LLRD doses
• RnP doses

All three of these dose targets were met.

Based on their compliance verification activities, such as site inspections, and reviews of licensee reports, work practices, monitoring results and individual effective dose results in 2017, CNSC staff were satisfied that AREVA controlled radiation doses to workers. CNSC staff concluded that the worker dose control measures at the McClean Lake Operation were highly effective, and therefore rated AREVA’s performance for the radiation protection SCA at the McClean Lake Operation as “fully satisfactory” in 2017.

#### 7.3 Environmental protection

For 2017, CNSC staff continued to rate the environmental protection SCA as “satisfactory” based on regulatory oversight activities. CNSC staff concluded that the licensee’s environmental protection program was effectively implemented and met all regulatory requirements.

McClean Lake Operation – Environmental protection ratings
2013 2014 2015 2016 2017
SA SA SA SA SA
SA = satisfactory
##### Environmental management system

AREVA has implemented and is maintaining an effective environmental management system. Internal audits are conducted to verify and ensure the system’s continued effectiveness. Any deficiencies and findings identified from internal audits are documented and plans are devised to address any instances of non-conformance with requirements for environmental management. In 2017, CNSC staff verified the implementation of AREVA’s environmental management system at McClean Lake through desktop reviews of quarterly environmental reports, annual compliance reports, and onsite inspections.

##### Environmental risk assessment

AREVA submitted an updated environmental risk assessment (ERA) in 2016. CNSC staff reviewed the document and noted the predicted ecological and human health risks from the McClean Lake Operation were within predictions of CNSC‑accepted environmental impact statements and ERAs, with the exception of predicted short-term exposure of aquatic organisms to selenium in McClean Lake’s east basin. McClean Lake’s east basin is considered an exposure lake. AREVA proposed a selenium adaptive management plan, discussed below, to address this. CNSC staff concluded that the McClean Lake Operation is in compliance with regulatory requirements. Details on ERAs are also provided in section 2.4 of this document.

CNSC staff conducted an environmental assessment under the Nuclear Safety and Control Act (NSCA) as part of the McClean Lake Operation’s June 2017 licence renewal. CNSC staff concluded that AREVA had made, and will continue to make, adequate provision for the protection of the environment and the health of persons.

###### Selenium management plan update

After restart and commissioning of the McClean Lake mill in September 2014, AREVA identified an increasing trend in selenium concentration in the effluent from the JEB water treatment plant. The increase in concentrations in effluent was attributed to the milling of Cigar Lake ore. Although values remained well below the provincial limit of 0.6 mg/L, AREVA was proactive and implemented process improvements to control selenium, including:

• an interim administrative level of 0.084 mg/L and action level of 0.112 mg/L
• a selenium adaptive management plan

In March 2017, AREVA submitted a formal selenium adaptive management plan that included the following strategies:

• a pollution prevention plan
• best available technology economically achievable assessment plan
• an active commissioning plan

The selenium adaptive management plan outlines selenium-related continual improvement and adaptive management actions taken at the McClean Lake Operation. These actions include changes to leaching and tailings preparation circuits, changes to the hydrogen peroxide concentration and delivery system, and physical changes to improve hydrogen peroxide mixing.

CNSC staff reviewed the selenium adaptive management plan to verify that AREVA was taking adequate measures to manage and control selenium releases from the McClean Lake Operation, and to verify that the plan met their expectations. They concluded that the plan met regulatory requirements, and the plan was accepted in August 2017. CNSC staff continue to review reported selenium concentrations in effluent to ensure that the receiving environment remains protected. This information was also provided to address the Commission request, as part of the 2017 McClean Lake licence renewal, to provide an update on the progress related to the selenium management program and selenium effluent at the McClean Lake Operation.

##### Assessment and monitoring

Environmental monitoring programs serve to demonstrate that site emissions, wastes, tailings and effluent discharge of nuclear and hazardous substances are properly controlled. CNSC staff review environmental effects monitoring information along with the results of other routine or special investigations, to ensure that any impacts to the receiving environment and biota are identified. CNSC staff noted that AREVA had continued with routine site inspections, internal audits, environmental training and periodic reviews of environmental monitoring data. These activities were conducted to ensure continual improvement and to confirm that the controls put into place to protect the environment were effective. CNSC staff assessed AREVA’s environmental management system and monitoring programs at McClean Lake and concluded that they met regulatory requirements, and that the licensee complied with treated effluent discharge requirements during 2017.

The following provides monitoring and assessment results for the McClean Lake Operation.

##### Effluent and emissions control
###### Treated effluent released to the environment

At the McClean Lake Operation, two effluent streams are processed in separate treatment facilities before being released to the environment:

• The mill effluent is processed at the JEB water treatment plant with a treatment system of chemical precipitation and liquid/solid separation. Treated water is released to the sink/vulture treated effluent management system.
• The Sue water treatment plant treats effluent, which is pumped to control the water level from the mined-out open pits, using a chemical precipitation and settling pond clarification process. This effluent is then released to the sink/vulture treated effluent management system.

The treated effluent is released in a controlled manner. Monitoring has verified ERA predictions supporting that this effluent poses no environmental concern. There were no action level exceedances associated with the JEB water treatment plant in 2017.

The Sue water treatment plant is operational only in summer months. In 2017, there were no action level exceedances associated with the Sue water treatment plant.

AREVA analyzed treated effluent for concentrations of various substances such as radium-226, arsenic, copper, lead, nickel, zinc and total suspended solids, and for pH levels at McClean Lake. As discussed in section 2.4, the McClean Lake Operation continued to meet Metal Mining Effluent Regulations discharge limits.

CNSC staff will continue to review results on the quality of effluent, in order to ensure that the treatment of effluent remains effective.

###### Air emissions released to the environment

Air quality at the McClean Lake Operation is monitored through direct measurement of emissions from the mill, ambient air quality near the operation, and indirectly through measurements of metal accumulations in the terrestrial environment.

Air quality monitoring at the McClean Lake Operation includes ambient radon, total suspended particulate (TSP), sulphur dioxide and exhaust stack monitoring. Ambient sulphur dioxide and exhaust stack monitoring was commensurate with the mill commissioning activities and restart in September 2014. Terrestrial monitoring components include soil and vegetation sampling.

Environmental monitoring for radon concentrations is conducted using the passive method of track-etched cups. There are 23 monitoring stations in various locations around the site-lease boundary. Figure 7.4 shows the average concentrations of radon in ambient air for 2013 to 2017. Ambient radon concentrations were typical of the northern Saskatchewan regional background of less than 7.4 Bq/m3 to 25 Bq/m3. The measured radon concentrations were also below a reference radon concentration of 55 Bq/m3, which is equal to an incremental dose of 1 mSv per year above background.

Five high-volume air samplers to monitor TSP are located at locations around the McClean Lake Operation. As shown in table 7.2, TSP values remained low in 2017 and well below the provincial standard of 60 µg/m3.

TSP samples were also analyzed for concentrations of metals and radionuclides. The mean concentrations of metal and radionuclides adsorbed to TSP were low and below reference annual air quality levels identified in table 7.2.

Table 7.2: McClean Lake Operation – Concentrations of metal and radionuclides in air, 2013–17
Parameter Reference annual air quality level* 2013 2014 2015 2016 2017
As (µg/m3) 0.06 (1) 0.000226 0.000420 0.003070 0.000032 0.000432
Cu (µg/m3) 9.6 (1) 0.036192 0.013888 0.019630 0.021613 0.017159
Mo (µg/m3) 23 (1) 0.000657 0.000721 0.000892 0.000145 0.001028
Ni (µg/m3) 0.04 (1) 0.000258 0.000420 0.000247 0.000259 0.000321
Pb (µg/m3) 0.10 (1) 0.000422 0.000501 0.000368 0.000762 0.000406
Zn (µg/m3) 23 (1) 0.005896 0.005939 0.005452 0.004703 0.003165
Pb210 (Bq/m3) 0.021 (2) 0.000763 0.000277 0.000271 0.000285 0.000309
Po210 (Bq/m3) 0.028 (2) 0.000159 0.000088 0.000083 0.000087 0.000100
Ra226 (Bq/m3) 0.013 (2) 0.000013 0.000010 0.000008 0.000009 0.000014
Th230 (Bq/m3) 0.0085 (2) 0.000000 0.000005 0.000005 0.000005 0.000006
U (µg/m3) 0.06 (1) 0.000328 0.000576 0.001319 0.003138 0.002029
TSP (µg/m3) 60 (3) 6.78 5.66 8.37 5.12 4.96

1 Reference annual air quality levels are derived from Ontario 24-hour Ambient Air Quality Criteria (OMOE 2012).

2 Reference level is derived from International Commission of Radiological Protection (ICRP) Publication 96 Protecting People Against Radiation Exposure in the Event of a Radiological Attach.

3 Saskatchewan Environmental Quality Guidelines, table 20: Saskatchewan Ambient Air Quality Standards. Values are calculated as geometric means.

* Reference levels are based on Province of Ontario Ambient Air Quality Criteria and are shown for reference only. No federal or Province of Saskatchewan limits were established at the time of this report.

A sulphur dioxide monitor is used during operations to continuously measure ambient sulphur dioxide concentrations associated with mill emissions. The monitor is located approximately 200 metres downwind of the sulphuric acid plant stack. The measured sulphur dioxide monitoring data (figure 7.5) showed no exceedances of the annual standard of 20 µg/m3 in 2017.

Action levels have also been established for ambient sulphur dioxide concentrations. The 1-hour and 24-hour action levels are 0.170 parts per million (ppm) and 0.060 ppm, respectively. In 2017, there were two events where action levels for sulphur dioxide were excedeed. These events were of short duration and were the result of acid plant start-ups. During acid plant start-up, until the plant reaches operating temperature, it is normal to have higher sulphur dioxide emissions. CNSC staff reviewed the follow-up reports and were satisfied with the corrective actions implemented by the McClean Lake Operation.

AREVA’s terrestrial monitoring program at McClean Lake determines if there is influence on the environment from aerial deposition. Soil and terrestrial vegetation may be affected by the atmospheric deposition of particulate and adsorbed metals and radionuclides associated with onsite activities. This program includes measurements of metals and radionuclides in soil and vegetation.

Soil monitoring results from soil samples collected in 2015 were presented in the 2016 environmental performance report (EPR). The results showed that the soil metal parameter concentrations were below the Canadian Environmental Quality Guidelines set by the Canadian Council of Ministers of the Environment. Radionuclide concentrations in soils were near or at background levels and analytical detection limits. CNSC staff concluded that the level of airborne particulate contaminants produced by the McClean Lake Operation is acceptable and does not pose a risk to the environment.

Vegetation sampling was also presented in the 2016 EPR and shows that most parameters are within the range of concentrations previously measured in lichen, Labrador tea and blueberry twig samples. The concentrations of metals and radionuclides in lichen, Labrador tea and blueberry twigs have higher than background concentrations for some samples located in the immediate vicinity of mining activity, although the concentrations decrease within a short distance. Overall, the results indicated that the McClean Lake Operation has had a localized effect on vegetation in areas of activity. These higher concentrations were below levels that are toxic to plants and decreased to within-background concentrations within a short distance. Therefore, no changes are predicted to terrestrial habitat, both within and outside the site boundary. The elevated concentrations of contaminants within the site boundary were modelled in an ERA, and no adverse effects were predicted for terrestrial non-human biota.

CNSC staff concluded that the level of airborne particulate contaminants produced by the McClean Lake Operation was acceptable and did not pose a risk to browse (twigs and Labrador tea) and lichen consumers such as caribou.

##### Uncontrolled releases

In 2017, three events reported to CNSC staff were submitted as releases of hazardous substances to the environment:

• On January 12, 2017 approximately 2 litres of anhydrous ammonia leaked onto the ground during off‑loading of the product.
• On June 26, 2017 approximately 1,000 litres of pond sludge at the surface access borehole resource extraction (SABRE) project site discharged to the ground during suctioning of pond sludge into the hydrovac truck. Most of the material returned to the pond.
• On August 29, 2017 approximately 50 kilograms of sulphuric acid discharged through the gap around the sump.

All three spills were minor and reporting met the requirements of RD/GD-99.3, Public Information and Disclosure. Appendix H describes the spills and corrective actions taken. As a result of actions taken by AREVA, there were no residual impacts to the environment by the spills. CNSC staff were satisfied with the reporting of releases of hazardous materials to the environment and the corrective actions taken. CNSC staff rated all the 2017 spills as “low significance”.

Figure 2.5 in section 2 displays the number of environmental reportable spills that occurred at the McClean Lake Operation from 2013 to 2017.

##### Protection of the public

AREVA is required to demonstrate that the health and safety of the public are protected from exposures to hazardous substances released from the McClean Lake Operation. The effluent and environmental monitoring programs currently conducted by the licensee are used to verify that releases of hazardous substances do not result in environmental concentrations that may affect public health.

The CNSC receives reports of discharges to the environment through the reporting requirements outlined in the licence and licence conditions handbook. The review of AREVA’s hazardous (non-radiological) discharges to the environment at McClean Lake in 2017 indicated that the public and environment were protected. CNSC staff confirmed the environmental concentrations in the vicinity of the McClean Lake Operation remained within those predicted in the 2016 ERA, and that human health remained protected.

Based on their reviews of the programs at the McClean Lake Operation, CNSC staff concluded that the public continued to be protected from operational emissions in 2017.

#### 7.4 Conventional health and safety

For 2017, CNSC staff continued to rate the conventional health and safety SCA as “satisfactory” based on regulatory oversight activities.

McClean Lake Operation – Conventional health and safety ratings
2013 2014 2015 2016 2017
SA SA SA SA SA
SA = satisfactory
##### Practices

As required under the NSCA, AREVA continued to improve performance and maintain health and safety programs at the McClean Lake Operation to minimize occupational health and safety risks. CNSC staff confirmed that AREVA had an effective occupational health and safety committee and that it was completing regular reviews of its safety program at McClean Lake.

AREVA’s McClean Lake Operation investigates safety concerns and incidents, including near-miss events. In 2017, several investigations were completed using the cause mapping process to determine the cause of incidents, near misses, injuries or property damage. This methodology employs a collaborative group effort to identify a problem, analyze its causes and determine the best solutions. CNSC staff reviewed the investigation results and corrective actions and confirmed AREVA’s commitment to accident prevention and safety awareness with a focus on safety culture.

##### Performance

Table 7.3 shows that from 2013 to 2017, AREVA’s McClean Lake Operation reported nine lost‑time injuries (LTIs). There were no LTIs in 2017.

Table 7.3: McClean Lake Operation – Lost-time injury statistics, 2013–17
2013 2014 2015 2016 2017
Lost-time injuries1 0 3 3 3 0
Accident severity rate2 0.0 4.3 27.7 10.9 67.8
Accident frequency rate3 0.0 0.4 0.4 0.6 0.0

1 An injury that takes place at work and results in the worker being unable to return to work for a period of time.

2 A measure of the total number of days lost to injury for every 200,000 person-hours worked at the site.
Accident severity rate = [(# of days lost in last 12 months) / (# of hours worked in last 12 months)] x 200,000.

3 A measure of the number of LTIs for every 200,000 person-hours worked at the site.
Accident frequency rate = [(# of injuries in last 12 months) / (# of hours worked in last 12 months)] x 200,000.

CNSC staff reported the three LTIs from 2016 during a June 2017 Commission public hearing to consider the McClean Lake Operation licence renewal (CMD 17-H9).

The severity rate for McClean Lake LTI statistics is calculated from time lost in 2017 as a result of events occurring in previous years. An event that occurred in October 2014 resulted in an LTI after a worker experienced respiratory health effects from being exposed to sulphur dioxide in the acid plant. In February 2017, the worker was required to take time off work and has not yet returned to work. Another worker was exposed to ammonium sulphate in 2015 and experienced sensitivities to the chemical. As a result, this worker was required to take time off from July to December 2017.

Corrective actions, were implemented where necessary and their effectiveness was verified and documented by management. CNSC staff observed that AREVA strives to involve all levels of its organization in the health and safety program at the McClean Lake Operation. Employees are encouraged and trained to continuously identify and assess risks, and propose solutions.

##### Awareness

CNSC staff observed that conventional health and safety programs provided education, training, tools and support to ensure worker protection at McClean Lake. An active onsite occupational health and safety committee completes regular reviews of the McClean Lake safety program. Through inspections, reviews of incidents and discussions with McClean Lake staff, CNSC staff verified that the McClean Lake Operation is committed to accident prevention and safety awareness. As a result of their compliance verification activities, CNSC staff concluded that the McClean Lake Operation’s health and safety program met regulatory requirements in 2017.

## Section II: Historic and Decommissioned Uranium Mine and Mill Sites

### 8. Overview

Section II of this report provides information on four decommissioned historic sites that are being actively remediated, and nine decommissioned uranium mine and mill sites (see figure 8.1for site locations).

The objective of active remediation projects is to establish long-term, stable conditions that ensure the safe use of each site by current and future generations. Wherever possible, the remediation plans aim to return historic uranium mine and mill sites to previously existing environmental conditions or to land uses that will be sustainable in the long term. Active remediation projects consist of ongoing cleanup activities involving full-time staff and contractors who manage different areas, as well as frequent monitoring and reporting.

The decommissioned sites discussed in this report are in the long-term maintenance and monitoring phase. They have a very low potential of exposing people to radiation, because of limited onsite work, the outdoor setting, and low radiation levels following remediation activities that have already been completed.

The following four historic mine sites are undergoing active remediation:

• Gunnar legacy uranium mine
• Lorado uranium mill
• Deloro mine
• Madawaska legacy uranium mine

The following nine sites have been decommissioned for several years and are currently in the long-term monitoring and maintenance phase:

• Beaverlodge mine and mill
• Cluff Lake uranium mine and mill
• Rayrock mine
• Port Radium mine
• Agnew Lake uranium mine
• Bicroft tailings storage facility
• Dyno closed mine
• Elliot Lake historic sites
• Denison and Stanrock mining facilities

#### 8.1 CNSC regulatory efforts

CNSC staff provide risk-informed regulatory oversight of licensed activities at the active remediation projects and decommissioned sites. According to CNSC staff’s risk-informed baseline inspection plan, all remediation projects and seven of the nine decommissioned sites are required to have at least one inspection per year. Two of the decommissioned mine sites (Rayrock and Port Radium) are inspected once every three years. Inspections for these two sites were completed in June 2016, as per CNSC staff’s baseline compliance verification plan.

Table 8.1 presents CNSC staff’s licensing and compliance efforts for historic and decommissioned sites in 2016 and 2017. CNSC staff performed 18 compliance inspections in 2016 and 12 compliance inspections in 2017 at these sites. Findings from these inspections were provided to licensees in detailed inspection reports. All enforcement actions arising from the findings were recorded in the CNSC Regulatory Information Bank to ensure that they were tracked to completion. CNSC staff reviewed licensees’ corrective actions and verified that these actions were appropriate and acceptable. All notices of non-compliance issued in 2016 and 2017 are considered closed by CNSC staff. Details of enforcement actions are provided in the following sections.

Table 8.1: CNSC licensing and compliance activities for historic and decommissioned sites, 2016–17
Site 2016 2017
Number of inspections Compliance activity effort (person-days) Licensing activity effort (person-days) Number of inspections Compliance activity effort (person-days) Licensing activity effort (person-days)
Gunnar 1 59 71 1 53 17
Lorado 1 18 8 1 24 0
Deloro 2 85 31 2 41 80
Madawaska 1 20 0 0* 2 1
Beaverlodge 1 39 18 1 59 7
Cluff Lake 1 70 25 1 69 71
Rayrock 1 8 1 0** 5 42
Port Radium 1 31 10 0** 8 1
Agnew Lake 1 6 1 1 12 2
Bicroft 1 6 0 1 19 0
Dyno 1 9 0 1 7 0
Elliot Lake 2 60 1 1 22 4
Denison 2 25 2 1 7 0
Stanrock 2 28 1 1 7 0

*    Inspection was deferred to 2018–19 due to poor weather conditions and ongoing site maintenance.

**  Baseline compliance inspections are planned every three years. Inspection was completed in 2016. The next inspection is planned for 2019.

Licensing information for each site is found in appendix A.

The CNSC requires licensees to develop decommissioning plans for each of their sites. Each plan, reviewed and approved by CNSC staff, is accompanied by a financial guarantee that provides the funding necessary to complete all decommissioning work. For sites that have been decommissioned, financial guarantees are still required to support monitoring, care and maintenance of the site.

The values of the financial guarantees for the historic and decommissioned sites are listed in appendix F.

#### 8.2 Performance

The CNSC requires all licensees, as per their CNSC licences, to submit annual compliance reports with information pertaining to their performance in the applicable safety and control areas (SCAs). CNSC staff review these reports to verify if licensees are complying with regulatory requirements and are operating safely. These reports are available on licensees’ websites, as applicable (see appendix L of this report for Web links).

CNSC staff reviewed licensee compliance reports, revisions to licensee programs, licensee responses to events and incidents, and results of their inspections to compile the performance ratings for the active remediation projects and decommissioned sites.

The following SCAs were not rated for any of the remediation projects and decommissioned sites:

• Human performance management: This SCA is not applicable, as the routine monitoring and maintenance activities carried out at decommissioned mine and mill sites require a very low level of onsite worker presence.
• Safety analysis: A safety analysis is completed at the licensing stage and used throughout the lifecycle of each site. Due to the static nature of historic and decommissioned sites, new safety analyses are not required.
• Waste management: This SCA does not apply, as the authorized licence activities are all related to the management of wastes for the decommissioned sites ( rather than operational sites).
• Safeguards and non-proliferation: This SCA is not applicable because each site has been decommissioned and the risk for intervention is very low. Licensees are required to provide reasonable services and assistance to the International Atomic Energy Agency (IAEA) inspectors to carry out their duties and functions. During the 2016 and 2017 calendar year, there were no requests by IAEA inspectors to inspect any of these sites.
• Packaging and transport: Licensees of historic and decommissioned sites do not ship radioactive materials, so the packaging and transport SCA does not apply.
• Operating performance: This SCA was not rated since historic and decommissioned sites do not operate.

Tables 8.2, 8.3 and 8.4 present the ratings for applicable SCAs for each historic and decommissioned sites for 2016 and 2017.

For 2016 and 2017, CNSC staff rated all applicable SCAs as “satisfactory” for all historic sites (see table 8.2).

As shown in table 8.3, all but three decommissioned sites received ratings of “satisfactory” for all applicable SCAs in 2016; Rayrock, Port Radium and Agnew Lake mines were rated “below expectations” in the radiation protection SCA (see sections 15 to 17 for additional information).

As shown in table 8.4, most decommissioned sites received ratings of “satisfactory” for applicable SCAs in 2017; Elliot Lake sites were rated “below expectations” in the environmental protection SCA (see section 20 for more information).

Appendix E contains the applicable SCA performance ratings from 2015 to 2017 for historic and decommissioned mine and mill sites.

Table 8.2: Applicable SCA performance ratings for historic sites, 2016–17
Safety and control area Gunnar Lorado Madawaska Deloro
Management system SA SA SA SA
Physical design SA SA SA SA
Radiation protection SA SA SA SA
Conventional health and safety SA SA SA SA
Environmental protection SA SA SA SA
Emergency management and fire protection SA SA SA SA
Security SA SA SA SA
SA = satisfactory
Table 8.3: Applicable SCA performance ratings for decommissioned sites, 2016
Safety and control area Beaverlodge Cluff Lake Rayrock Port Radium Agnew Lake Bicroft Dyno Elliot Lake Denison and Stanrock
Radiation protection SA SA BE* BE* BE* SA SA SA SA
Conventional health and safety SA SA SA SA SA SA SA SA SA
Environmental protection SA SA SA SA SA SA SA SA SA

BE = below expectations SA = satisfactory

*See sections 15 to 17 for more information.

Table 8.4: Applicable SCA performance ratings for decommissioned sites, 2017
Safety and control area Beaverlodge Cluff Lake Rayrock Port Radium Agnew Lake Bicroft Dyno Elliot Lake Denison and Stanrock
Radiation protection SA SA SA SA SA SA SA SA SA
Conventional health and safety SA SA SA SA SA SA SA SA SA
Environmental protection SA SA SA SA SA SA SA BE* SA

BE = below expectations

SA = satisfactory

* See section 20 of this report for more information

This report focuses on the three SCAs that cover many of the key performance indicators for historic and decommissioned sites: radiation protection, environmental protection and conventional health and safety.

#### 8.3 Radiation protection

The radiation protection SCA covers the implementation of a radiation protection program in accordance with the Radiation Protection Regulations. This program must ensure that contamination levels and radiation doses received by individuals are monitored, controlled and maintained as low as reasonably achievable (ALARA).

##### Radiological hazard control

Sources of radiation exposure at historic and decommissioned sites include:

• gamma radiation
• long-lived radioactive dust
• radon progeny
• radon gas

Through their verification activities, CNSC staff found that the licensees controlled these hazards through practices related to the effective use of time, distance and shielding; contamination control; and personal protective equipment.

##### Radiation protection performance

During 2016 and 2017, CNSC staff conducted regulatory oversight activities in the radiation protection SCA at all historic and decommissioned sites, in order to evaluate if licensees were complying with regulatory requirements.

Overall, CNSC staff concluded that licensees had adequate radiation protection practices identified for the work activities being conducted in 2016 and 2017, and for ensuring the protection of health and safety of persons working at their sites.

##### Worker dose control

Tables G-8 and G-9 in appendix G show the maximum and average effective doses to nuclear energy workers (NEWs) at historic and decommissioned sites, for 2016 and 2017. The only sites with workers designated as NEWs during these reporting periods were Gunnar, Deloro, Madawaska, Denison and Stanrock, and Elliot Lake. The maximum individual effective dose to a NEW at these sites ranged from 0.6 mSv to 1.02 mSv in 2016, and from 0.61 mSv to 1.37 mSv in 2017. These values were all well below the regulatory dose limit of 50 mSv per year and 100 mSv in a five-year dosimetry period.

Annual effective doses to NEWs are based on work conditions and environments that vary among work sites. Therefore, direct comparisons of effective doses to workers at different sites do not necessarily provide appropriate measures of the effectiveness of radiation protection programs.

There were no workers designated as NEWs at the Beaverlodge, Cluff Lake, Rayrock, Port Radium, Agnew Lake, Bicroft and Dyno sites during 2016 and 2017.

##### Application of ALARA

The CNSC requirement to apply the ALARA principle has consistently resulted in doses well below regulatory dose limits at historic and decommissioned sites. Based on the review of the work activities conducted at these sites and the dose data provided in Appendix G, CNSC staff are satisfied that all licensees controlled radiation doses so as to keep them below regulatory dose limits for NEWs and in accordance with the ALARA principle.

##### Estimated dose to the public

The maximum allowable dose to the public from licensed activities at each of the remediation projects and decommissioned sites is based on a human health risk assessment and supported with monitoring data. In 2016 and 2017, doses to the public from historic and decommissioned sites continued to be well below the regulatory annual public dose limit of 1 mSv due to the limited site accessibility; this is confirmed through dose readings obtained during CNSC compliance inspections.

#### 8.4 Environmental protection

The environmental protection SCA covers programs that identify, control and monitor all releases of radioactive and hazardous substances and the effects on the environment from facilities or as the result of licensed activities.

The historic and decommissioned sites received a rating of “satisfactory” for the environmental protection SCA for 2016 and 2017, with the exception of Elliot Lake, which was rated “below expectations” for environmental protection, because of an exceedance of a monthly licence limit (see section 20.3 for more information).

In 2016 and 2017, environmental protection programs were effectively implemented and met regulatory requirements for all historic and decommissioned sites. There were no exceedances of effluent discharge limits with the exception of Elliot Lake historic sites due to the exceedance of radium-226 at the Stanleigh effluent treatment plant (section 20). Despite the exceedance at Elliot Lake, the environment remains protected as CNSC staff requested the licensee to increase water quality monitoring and toxicity testing for aquatic biota. The sampling results, and a subsequent reactive inspection by CNSC staff, confirmed that the exceedance did not result in any radiological impacts to members of the public or the environment.

##### Water quality objectives

Water quality is typically compared to the Canadian Water Quality Guidelines for the Protection of Aquatic Life, Health Canada’s Guidelines for Canadian Drinking Water Quality and/or to provincial levels where applicable. For example, for sites in Saskatchewan, water quality is compared to the province’s Surface Water Quality Objectives. In some cases, there are site‑specific objectives that are based on risk assessments at the time of licensing. Water quality objectives for each site are provided in their respective sections.

#### 8.5 Conventional health and safety

The conventional health and safety SCA covers the implementation of programs to manage workplace safety hazards and to protect workers and equipment.

For 2016 and 2017, CNSC staff rated the conventional health and safety SCA at historic and decommissioned sites as “satisfactory”.

##### Practices

Licensees are responsible for developing and implementing conventional health and safety program for the protection of staff and contract workers. These programs must comply with Part II of the Canada Labour Code. CNSC staff reviewed licensee annual reports and conducted site inspections where safety practices were observed. They concluded that licensees implemented their conventional health and safety programs satisfactorily during 2016 and 2017, and that licensee programs were effective in protecting the health and safety of persons working in their facilities.

##### Performance

A key performance measure for conventional health and safety is the number of lost-time injuries (LTIs) per facility. An LTI is a workplace injury that results in the worker being unable to return to work for a period of time. There were no LTIs at any of the historic and decommissioned sites during 2016 and 2017.

## Section II-A: Historic Uranium Mine and Mill Sites

This section provides information on CNSC’s oversight of four active remediation projects of historic uranium mine and mill sites in Saskatchewan and Ontario.

### 9. Gunnar

The Gunnar legacy uranium mine site is located approximately 600 kilometres north of Saskatoon, on the north shore of Lake Athabasca in northwest Saskatchewan.

Gunnar was a commercial uranium mine that operated from 1955 to 1963. The site closed in 1964, with little decommissioning performed at the time. The former uranium mine and mill is being remediated by the Saskatchewan Research Council (SRC). Following a November 2014 public hearing, the Commission issued SRC a waste nuclear substance licence for the Gunnar Remediation Project. SRC’s licence is valid until November 30, 2024.

The remediation project consists of the cleanup of mine tailings, waste rock piles (see figure 9.2), an open pit, a mine shaft and demolition debris. The remediation work is being carried out in three phases. Phase 1, which is now complete, involved characterizing and monitoring the onsite waste and developing remediation plans. Phase 2, which is ongoing, consists of implementing the remediation plans. Phase 3 will involve long-term monitoring and maintenance to ensure that the site remains stable and safe.

When the Commission issued the CNSC licence for the Gunnar Remediation Project, it included a regulatory hold point for phase 2. Following a public hearing in September 2015, the Commission removed part of this hold point, allowing the remediation of the site’s tailings area to proceed. A subsequent public Commission hearing was held on September 22, 2016, at SRC’s request, to remove the remainder of the hold point and authorize the remediation of the waste rock piles, open pit, mine shaft and demolition debris.

In 2016 and 2017, work conducted at the Gunnar site consisted of:

• procurement of a contractor to conduct tailings remediation work
• initial mobilization and preparation for remediation activities
• development of borrow areas and haul road construction
• grading of Gunnar main tailings surface
• excavation and placement of waste rock on Gunnar main tailings (see figures 9.1 and 9.2)
• planning for other cleanup aspects at the Gunnar site

#### 9.1 Performance

For 2016 and 2017, CNSC staff were satisfied with SRC’s performance at the Gunnar site in the SCAs of radiation protection, conventional health and safety, environmental protection, security, and emergency management and fire protection.

The CNSC’s baseline inspection plan for 2016 and 2017 required CNSC staff to conduct one site inspection per year at the Gunnar site. CNSC staff conducted inspections of the site in August 2016 and August 2017. The inspectors found that, overall, SRC was in compliance with its licence conditions, with the exception of requirements for labelling radioactive material and for controlling radiation zones. As a result of these instances of non-compliance, which were of low safety significance, enforcement notices were issued to SRC. SRC took immediate corrective actions, which were verified and approved by CNSC staff. These enforcement actions are now closed.

#### 9.2 Radiation protection

For 2016 and 2017, CNSC staff rated the radiation protection SCA as “satisfactory”.

Gunnar – Radiation protection ratings
2016 2017
SA SA
SA = satisfactory
##### Radiation protection program performance

CNSC staff reviewed radiation protection plans, worker dose records and radiation surveys submitted by SRC and conducted inspections at the Gunnar site. As a result, CNSC staff were satisfied with SRC’s implementation of its radiation protection program at the Gunnar site in 2016 and 2017.

##### Worker dose control

In 2016 and 2017, workers who were onsite for total periods exceeding four weeks were classified as nuclear energy workers (NEWs) and assigned appropriate dosimetry. In 2016, all workers onsite received a dose of less than the annual public dose limit, and the maximum dose received by a NEW was 0.6 mSv. In 2017, of the 98 workers on site, 4 NEWs received a dose greater than the public dose limit of 1 mSv/year, and the maximum individual effective dose received by a NEW was 1.37 mSv. All reported doses were below SRC’s action levels
(2.5 mSv/month), and were also below the CNSC’s regulatory dose limit of 50 mSv per year and 100 mSv in a five-year dosimetry period for workers designated as NEWs.

Passive radon emissions are monitored in the air at the Gunnar site. The radon monitored at the site perimeter during 2016 and 2017 was within natural background levels and therefore contributed a negligible dose to workers. CNSC staff reviewed monitoring results and confirmed that radon was adequately monitored in order to verify that the public and workers were protected. Long-lived radioactive dust is also monitored; CNSC staff reviewed these results and confirmed that the public and workers were protected.

#### 9.3 Environmental protection

For 2016 and 2017, CNSC staff rated the environmental protection SCA as “satisfactory”.

Gunnar – Environmental protection ratings
2016 2017
SA SA
SA = satisfactory
##### Assessment and monitoring

For 2016 and 2017, CNSC staff verified that SRC maintained an environmental protection program that ensures the protection of the public, and an environmental monitoring program that measures existing conditions at the site.

SRC performed semi-monthly surface water and groundwater monitoring and analyses over the 2016 and 2017 field seasons (May through October). CNSC staff reviewed the results of these analyses and found they were consistent with the previous year and with the 2014 Gunnar environmental impact statement.

There is no liquid effluent at the Gunnar site; however, there is overland flow and seepage from the site into local water bodies.

In addition to water quality and air monitoring, during the construction phase, SRC hired an independent contractor who walked the site daily to identify any potential impacts to the environment to ensure compliance of the primary contractor.

CNSC staff are satisfied that SRC has maintained an environmental protection program to ensure the protection of the public and to establish baseline conditions for the site prior to remediation.

#### 9.4 Conventional health and safety

For 2016 and 2017, CNSC staff rated the conventional health and safety SCA as “satisfactory”.

Gunnar – Conventional health and safety ratings
2016 2017
SA SA
SA = satisfactory
##### Health and safety program performance

CNSC staff confirmed that SRC’s health and safety program has been implemented effectively and employs the good practices of awareness, training, communication and reporting. Examples of these practices include daily toolbox meetings in which health and safety risks are assessed and health and safety meetings to discuss broader health and safety issues on site.

This site has an active monitoring and reporting program for LTIs. There have been no LTIs at the Gunnar site in the reporting period of 2016 and 2017.

CNSC staff are satisfied with SRC’s performance in the area of conventional health and safety for the Gunnar site.

### 10. Lorado

The Lorado tailings management site is located 8 kilometres south of Uranium City, Saskatchewan (see figure 10.1).

The Lorado uranium mill operated from 1957 to 1960 and was abandoned in the 1960s without any decommissioning or remedial work. The Province of Saskatchewan now has ownership of the site under the Saskatchewan Ministry of the Economy. The ministry has subsequently appointed the Saskatchewan Research Council (SRC) as the project manager to oversee the ongoing management and remediation of the Lorado site. Issued in 2014, SRC’s waste nuclear substance licence for Lorado is valid until April 30, 2023.

SRC has completed remediation of the Lorado site. Remediation activities consisted of the placement of an engineered cover over the mine tailings; treatment of water in Nero Lake to neutralize acidity, and to reduce contaminant concentrations; and environmental monitoring. In 2016, SRC completed the placement of till in the remaining areas of the cover, installed rip-rap on the shore of Nero Lake and initiated the revegetation of the cover. This concluded the active remediation activities planned for Lorado. In 2017, SRC continued to monitor the local environment and the progress of the revegetation of the cover.

The next step for the site is to transition to the long-term monitoring phase, which is planned for 2018 or 2019. CNSC staff performed a review of the as-built plans for the remediation. The long‑term objective is to transfer the remediated safe and stable site into the Saskatchewan Institutional Control Program after a period of 10 to 15 years post-remediation.

#### 10.1 Performance

As a result of the findings of desktop reviews and general compliance inspections, CNSC staff were satisfied with SRC’s performance in 2016 and 2017 at the Lorado tailings management site, in the applicable SCAs of radiation protection, conventional health and safety, and environmental protection.

CNSC staff conducted inspections of the Lorado tailings management site in 2016 and 2017 and verified that SRC was in compliance with its licence. No compliance actions were issued as a result of the inspections.

#### 10.2 Radiation protection

For 2016 and 2017, CNSC staff rated the radiation protection SCA as “satisfactory”.

Lorado – Radiation protection ratings
2016 2017
SA SA
SA = satisfactory
##### Worker dose control

For 2016, all personnel at the Lorado site were treated as non-NEWs because of the very low radiation hazard risks, as the remediation work had been completed. Gamma surveys, conducted upon the completion of remediation activities in 2016, showed that the average dose rate on the covered tailings was 0.14 µSv/hr. Radon and long-lived radioactive dust were also monitored on site and found to pose a negligible radiation risk. In 2017, there were no workers or contractors on the Lorado site.

Because of the low dose rates on the covered tailings and the short periods of time spent by workers onsite in 2016, the dosimetry program that was in place during the remediation was discontinued.

#### 10.3 Environmental protection

For 2016 and 2017, CNSC staff rated the environmental protection SCA as “satisfactory”.

Lorado – Environmental protection ratings
2016 2017
SA SA
SA = satisfactory
##### Assessment and monitoring

SRC’s environmental program ensures that the environment and health and safety of persons are protected by identifying, controlling and monitoring all potential releases from remediation activities.

There is no liquid effluent at the Lorado site. SRC’s environmental sampling program includes measurement of surface water concentrations for metals, radionuclides and general water quality parameters in local lakes and groundwater. CNSC staff verified that SRC conducted surface water monitoring at several locations to confirm water quality improvement in Nero Lake and Hanson Bay following the placement of the cover on the tailings. As more data is collected over time at the site, the effectiveness of the remediation works can be verified. The public has also been advised of waterbodies from which fish consumption should be limited because of elevated selenium levels, which have resulted from past mining and milling activities at the Beaverlodge site and milling at the nearby Lorado site.

#### 10.4 Conventional health and safety

For 2016 and 2017, CNSC staff rated the conventional health and safety SCA as “satisfactory”.

Lorado – Conventional health and safety ratings
2016 2017
SA SA
SA = satisfactory
##### Health and safety program performance

CNSC staff confirmed through inspections that SRC’s health and safety program is implemented effectively and employs the good practices of awareness, training, communication and reporting. With the completion of the remediation work in early 2016 and no personnel remaining on site, there were no LTIs reported for the 2016 or 2017 reporting period.

For 2016 and 2017, CNSC staff were satisfied with SRC’s performance in the conventional health and safety SCA for the Lorado site. CNSC staff made this conclusion on the basis of compliance inspections as well as desktop reviews of quarterly and annual reports.

### 11. Deloro

The Deloro mine site is located approximately 65 kilometres east of Peterborough, Ontario. This site has an abandoned gold mine where metallurgical and refining processes related to the production of cobalt oxides and metal, and the extraction of silver, nickel and arsenic, took place.

In 2017, the CNSC issued a waste nuclear substance licence to the Ontario Ministry of Environment and Climate Change (MOECC), now known as Ontario’s Ministry of the Environment, Conservation and Parks. This licence allowed the continuation of remediation work at the Young’s Creek Area of the Deloro site, as work at both the industrial and mine area and tailings management area had been completed. The MOECC provided information in support of demonstrating that both areas were below conditional clearance levels, and these two areas have been removed from licensing. The footprint of the site now only includes the Young’s Creek Area (see figure 11.1). The Deloro waste nuclear substance licence is valid until October 31, 2022.

#### 11.1 Performance

For 2016 and 2017, CNSC staff rated MOECC’s performance as “satisfactory” in the safety and control areas (SCAs) of physical design, radiation protection, environmental protection, conventional health and safety, emergency management and fire protection, security, and management system. An update was provided in the Regulatory Oversight Report for Uranium Mines and Mills: 2016, explaining the change in rating for the management system SCA. CNSC staff verified the corrective measures and improvement undertaken by the licensee through inspections and other compliance verification and are now satisfied with the licensee’s performance in this SCA.

#### 11.2 Radiation protection

For 2016 and 2017, CNSC staff rated the radiation protection SCA as “satisfactory”.

Deloro – Radiation protection ratings
2016 2017
SA SA
SA = satisfactory
##### Radiation protection program performance

In 2016 and 2017, MOECC satisfactorily maintained a radiation protection program that ensured the protection of the workers and the public. Each contractor also has a specific radiation protection program for each cleanup project. All contractors and visitors attended radiation protection training prior to going onsite. In 2016 and 2017, CNSC staff verified that the licensee ensured that radiation protection training and records were up to date and maintained according to an approved dosimetry program.

##### Worker dose control

Contractors who are designated as nuclear energy workers (NEWs) onsite wore either thermoluminescent dosimeters or electronic personal dosimeters, depending on the tasks assigned. The average individual effective dose to Deloro mine site NEWs was less than 0.1 mSv; the maximum individual effective dose was 0.35 mSv in 2016. In 2017, as the work on the cover at the Industrial Mine Area was completed, the previously existing dosimetry program that was in place during the remediation was discontinued due to low dose rates.

For 2016 and 2017, CNSC staff were satisfied with the MOECC’s radiation protection program for the Deloro site.

#### 11.3 Environmental protection

For 2016 and 2017, CNSC staff rated the environmental protection SCA as “satisfactory”. CNSC staff were satisfied that the MOECC maintained an effective environmental protection program.

Deloro – Environmental protection ratings
2016 2017
SA SA
SA = satisfactory
##### Assessment and monitoring

The environmental monitoring program at the Deloro site includes monitoring of surface water and groundwater for radiological and non-radiological (hazardous) contaminants. Since 2011, the licensee has been responsible for enhanced environmental monitoring, including monitoring of air quality, noise, and archaeological and biological elements. The licensee also ensures healthy habitat and suitable conditions for all resident fish and wildlife.

MOECC’s surface water monitoring program consists of the collection and analysis of up to 22 sampling locations on and near the site. CNSC staff reviewed the 2016 and 2017 surface water results for radionuclides, which showed all samples were well below Health Canada’s Guidelines for Canadian Drinking Water Quality. The main contaminant of concern at the site is arsenic. In 2016 and 2017, arsenic concentrations in surface water in Young’s Creek exceeded the Canadian Council of Ministers of the Environment’s Canadian Environmental Quality Guidelines for assessing non-radiological contaminants. This finding is consistent with those in previous years. The concentration of arsenic is expected to decrease following completion of all remediation activities.

The site has a number of groundwater monitoring wells throughout the property. All radionuclides in groundwater were well below the Ontario Drinking Water Quality Standards.

##### Protection of the public

CNSC staff are satisfied that the MOECC had adequate measures in place at the Deloro site to protect the public and the environment from releases from its facility in 2016 and 2017. These measures included water treatment and a fence to prevent the public from accessing the site.

##### Independent Environmental Monitoring Program

To complement ongoing compliance activities, the CNSC has implemented its Independent Environmental Monitoring Program (IEMP) to independently verify that all persons and the environment around licensed nuclear facilities are protected. The IEMP involves taking samples from public areas around the facilities, and measuring and analyzing the amount of radioactive and hazardous substances in those samples. In 2016, CNSC staff conducted independent environmental monitoring around the Deloro mine site, including at locations along Young's Creek, and the Moira River downstream from the site. Results, which are available on the CNSC’s IEMP Web page, indicated that all persons and the environment in the vicinity of the Deloro site were protected, and there were no health impacts as a result of site activities.

#### 11.4 Conventional health and safety

For 2016 and 2017, CNSC staff rated the conventional health and safety SCA as “satisfactory”.

Deloro – Conventional health and safety ratings
2016 2017
SA SA
SA = satisfactory
##### Health and safety program performance

CNSC staff confirmed during an inspection that the MOECC’s health and safety program for the Deloro site has been implemented effectively, and that the program employs the good practices of awareness, training, communication and reporting. Occupational health and safety training is required for everyone who requires to access to the site, including contractors and visitors. CNSC staff are provided with this training on an annual basis.

This site has an active monitoring and reporting program for lost-time injuries. There were no lost-time injuries at the Deloro site in 2016 and 2017.

### 12. Madawaska

Madawaska, a legacy uranium mine located near Bancroft, Ontario, operated from 1957 to 1982 and was decommissioned in the 1980s. EWL Management Ltd. (EWL) is the licensee of the Madawaska mine site under a CNSC waste nuclear substance licence. The licence was issued on July 4, 2011 and is valid until July 31, 2021. For the foreseeable future, the site will remain under long-term monitoring and maintenance.

The site includes the footprint of the mining operation, a number of capped and sealed openings, underground workings and four tailings dams (see figure 12.1).

In 2016 and 2017, EWL continued rehabilitation/maintenance work on the two tailings management areas (TMAs). In 2017 the rehabilitation work at TMA 2 was completed and, work on approximately one-third of the area at TMA 1 was carried out. The new design contains features to reduce radon flux and increase the long-term physical stability of the TMAs. In addition, the maintenance work has eliminated any potential water ponding issues, has decreased erosion and has reduced future maintenance and monitoring requirements. A geotechnical inspection of the site is planned for fall 2018 to inspect the rehabilitated areas. It is planned to complete the TMA rehabilitation work in 2019.

#### 12.1 Performance

For 2016 and 2017, CNSC staff were satisfied with EWL’s performance at Madawaska in the safety and control areas (SCAs) of radiation protection, environmental protection, and conventional health and safety. EWL’s performance over the reporting period of 2016 and 2017 has been stable and met the requirements of the Nuclear Safety and Control Act and its associated regulations.

In 2016 CNSC staff found that the site was well managed and in compliance with requirements. No enforcement actions were issued as a result of the inspection conducted in 2016. The baseline compliance inspection scheduled for 2017 was deferred to 2018 because of poor weather conditions and ongoing maintenance of the site.

#### 12.2 Radiation protection

For 2016 and 2017, CNSC staff rated the radiation protection SCA as “satisfactory”.

Madawaska – Radiation protection ratings
2016 2017
SA SA
SA = satisfactory
##### Radiation protection program performance

For maintenance activities on the tailings, CNSC staff verified that EWL had an effective radiation protection program in place and that all nuclear energy workers (NEWs) at the Madawaska site followed appropriate dosimetry programs.

##### Worker dose control

Contractors who are designated as NEWs onsite wore either thermoluminescent dosimeters or electronic personal dosimeters, depending on the tasks assigned. In 2017, the average individual effective dose to NEWs at the Madawaska site was less than 0.07 mSv, and the maximum individual effective dose to a NEW was 0.61 mSv. The reported doses to all NEWs were below the licensee’s investigation levels and action levels, and were also below the regulatory limit of 50 mSv per year and 100 mSv in a five-year dosimetry period.

#### 12.3 Environmental protection

For 2016 and 2017, CNSC staff rated the environmental protection SCA as “satisfactory”. EWL satisfactorily maintained an environmental protection program to ensure the protection of the environment at the Madawaska site.

Madawaska – Environmental protection ratings
2016 2017
SA SA
SA = satisfactory

Concentrations in some waterbodies adjacent to the site exceeded the recommended maximum concentrations in the Canadian Water Quality Guidelines for the Protection of Aquatic Life for uranium in 2016 and 2017 (i.e., the highest value measured was 50 µg/L in Bow Lake compared to the water quality objective of 15 µg/L). These measurements were consistent with those from previous years. Risk assessments conducted in 2012 concluded that those values would not result in adverse effects on any species of aquatic life from exposure to those concentrations in surface water, sediment and groundwater associated with the Madawaska decommissioned site. However, with the improvements to water flow and the new cover system partially completed for the site, future results should demonstrate that migration of contaminants into the surrounding environment has been limited.

CNSC staff were satisfied that EWL had adequate measures in place to protect the public and the environment from releases from the Madawaska site in 2016 and 2017.

#### 12.4 Conventional health and safety

For 2016 and 2017, CNSC staff rated the conventional health and safety SCA as “satisfactory”.

Madawaska – Conventional health and safety ratings
2016 2017
SA SA
SA = satisfactory
##### Health and safety program performance

CNSC staff confirmed that EWL’s health and safety program has been implemented effectively and employs the good practices of awareness, training, communication and reporting.

CNSC staff also verified that EWL has a robust health and safety program and that all contractors and visitors were required to complete site-specific occupational health and safety training.

This site has an active monitoring and reporting program for lost-time injuries (LTIs). There were LTIs at the Madawaska site during 2016 and 2017.

CNSC staff are satisfied with EWL’s performance in the conventional health and safety SCA for the Madawaska site.

## Section II-B – Decommissioned Uranium Mines and Mills

Section II-B describes the nine uranium mine and mill sites that have been decommissioned and are in the long-term maintenance and monitoring phase. These sites generally have a very low potential of exposing workers and the public to radiation, given the limited nature of onsite work, the outdoor setting, and low radiation levels following remediation activities. In addition, CNSC staff have reviewed the risk assessments and monitoring data for all decommissioned sites, and concluded that levels of radiation exposure for 2016 and 2017 were well below the regulatory limits for non-nuclear energy workers. The doses to all nuclear energy workers performing monitoring, maintenance or site visits were also well below regulatory dose limits. All decommissioned sites received a rating of “satisfactory” for the radiation protection safety and control area (SCA) in 2016 and 2017 with the exception of Rayrock, Port Radium and Agnew Lake mines, which were rated “below expectations” in 2016. Additional information regarding the ratings for these three sites is provided in sections 15, 16 and 17, respectively.

Activities at decommissioned sites involve routine monitoring and maintenance work. In most cases there are no permanent staff on site. All sites maintain effective occupational health and safety programs that protect workers, contractors and visitors. The SCA rating for conventional health and safety at all sites was “satisfactory” in 2016 and 2017.

The environmental protection SCA is a key indicator for the effectiveness of past remediation measures and is highlighted for each site in this report. All decommissioned sites have environmental monitoring programs to ensure the continued protection of the environment and ongoing performance of remediation works. Once long-term environmental objectives for the site have been met, these sites may be released into institutional control or conditionally released from regulatory oversight. The SCA rating for environmental protection at most sites was “satisfactory” in 2016 and 2017; the only exception was a “below expectations” rating at the Elliot Lake historic sites for 2017. The following sections provide information about each decommissioned site, including any changes that occurred to the site in 2016 and 2017.

### 13. Beaverlodge

Beaverlodge was last reported on in the Regulatory Oversight Report for Uranium Mines and Mills in Canada: 2016; since then, there have been no significant changes to the site and the site has remained stable. Activities at the site have focused on preparing various properties for eventual transfer to the Saskatchewan Institutional Control Program.

The decommissioned Beaverlodge uranium mine and mill site is located near Uranium City in northwest Saskatchewan (figure 13.1).

Mining and milling activities began at the Beaverlodge site in 1952, and the mine closed in 1982. The Beaverlodge site consisted of a central mill, underground mine and a tailings management area (TMA). The TMA is located on the Fulton Creek watershed (shown in dark blue in figure 13.1 and shown again in figure 13.2). There are also several smaller satellite mines that provided ore during the three decades of operation.

Decommissioning commenced shortly after operations ended and was completed to the standards in place at the time of decommissioning (i.e., in 1985). Beaverlodge was the first uranium mining site in Canada to submit a formal decommissioning plan and to be decommissioned under an Atomic Energy Control Board licence. On behalf of the federal government, Cameco Corporation is the licensee and manages the site conducting routine environmental monitoring, environmental investigations and maintenance work, to ensure the site remains safe and secure.

The site consisted of 70 properties that covered an area of approximately 744 hectares. Saskatchewan’s Reclaimed Industrial Sites Act later came into effect and created an institutional control framework for the long-term provincial management of post-decommissioning properties. As a result, five decommissioned Beaverlodge properties were exempted from CNSC licensing by the Commission and entered into institutional control (IC) registry in 2009. This decision by the Commission was made following a presentation of information at a public hearing in February 2009.

On May 27, 2013 the Commission issued a 10-year licence for the Beaverlodge site. As part of its application, Cameco provided a plan for the implementation of additional remediation to support natural recovery of the site, and a timetable for final decommissioning of the site’s various licensed areas. Since issuance of that licence, Cameco completed studies and additional remediation work to support an application to release additional portions of the Beaverlodge site into the Province of Saskatchewan’s IC program. Cameco submitted an application in March 2016 for the proposed release of 14 properties, and a separate application in March 2018 for an additional 6 properties, with the intent to have the request for the exemption of these properties presented to the Commission in 2019. Should the Commission approve this request, the properties will be exempted from the current licence and will thereafter be administered under the Saskatchewan IC program. Work on the remaining 45 properties of the Beaverlodge site under the CNSC licence will continue to progress to a point that these sites can also be exempted from licensing. Cameco has expressed its intent to have the remaining properties exempted and transferred to IC prior to the licence renewal in 2023.

In addition to continued monitoring activities in 2016 and 2017, Cameco conducted property specific activities including: completion of the Bolger flow path reconstruction project; installation of stainless steel caps over previously remediated mine openings; utility corridor infrastructure cleanup; concrete pad remediation; culvert removal from a small tributary of Ace Creek; bulk fuel tank dismantling; and the remediation of an area to reduce gamma radiation levels.

CNSC staff will continue their oversight of the Beaverlodge site to verify regulatory compliance.

#### 13.1 Performance

In 2016 and 2017, CNSC staff rated the Beaverlodge site performance as “satisfactory” for all applicable safety and control areas (SCAs). The following sections contain additional information on the performance ratings for the SCAs of radiation protection, environmental protection, and conventional health and safety.

#### 13.2 Radiation protection

For 2016 and 2017, CNSC staff rated the radiation protection SCA as “satisfactory”.

Beaverlodge – Radiation protection ratings
2016 2017
SA SA
SA = satisfactory

There are no year-round workers at the Beaverlodge site. During 2016 and 2017, Cameco staff and contractors were onsite for limited periods of time for monitoring, mitigation activities and inspections. Based on the outcome of CNSC staff inspections and work practices, CNSC staff concluded that Cameco continued to be effective in controlling radiation doses to workers and the public at the Beaverlodge site.

#### 13.3 Environmental protection

For 2016 and 2017, CNSC staff rated the environmental protection SCA as “satisfactory”.

Beaverlodge – Environmental protection ratings
2016 2017
SA SA
SA = satisfactory

CNSC staff reviewed the water quality results from the 2016 and 2017 monitoring programs and found that the contaminant concentrations are generally stable and within the quantitative site model (QSM) predictions made by Cameco. Comparison of water quality monitoring results with the QSM predictions are one of the performance indicators used to determine if properties can be exempted from CNSC licensing and transferred into Saskatchewan’s Institutional Control Program. In some areas, radium concentration in surface waters are above the QSM predictions. As part of the five year ERA update in 2018, Cameco will reassess the environmental risk of radium in these areas and propose mitigation, if necessary. CNSC staff will review the ERA update and ensure regulatory compliance.

There is a precautionary fish consumption advisory in effect which, in 2016, was renamed and is now referred to as a Healthy Fish Consumption Guideline. The public has been advised of the lakes and creeks in the area from which no fish should be consumed. The public has also been advised of those water bodies where fish consumption should be limited due to elevated selenium levels as a result of past mining and milling activities at the Beaverlodge site and, as previously discussed in section 10, at the nearby Lorado site.

Radon levels are monitored on and around the Beaverlodge site. As was observed in past years, during this 2016 and 2017 reporting period, the radon levels at historic mine locations were generally above background levels. Radon concentrations were highest at the Ace Creek monitoring station and concentrations ranged between 155 Bq/m3 to a maximum of 350 Bq/m3. Concentration at the Uranium City station ranged between 5 Bq/m3 and 54 Bq/m3 in 2016 and 2017. The background concentration of radon in northern Saskatchewan ranges from less than 7.4 Bq/m3 to 25 Bq/m3. Radon levels for the far field and reference stations display a rapid decrease to background levels as the distance from the Beaverlodge site increases. Radon levels remain substantially below those observed prior to the decommissioning of the site.

For 2016 and 2017, CNSC staff were satisfied that Cameco had adequate measures in place to protect the public and the environment at the Beaverlodge site.

#### 13.4 Conventional health and safety

For 2016 and 2017, CNSC staff rated the conventional health and safety SCA as “satisfactory”.

Beaverlodge – Conventional health and safety ratings
2016 2017
SA SA
SA = satisfactory

The health and safety risks at the Beaverlodge site are very low for this unoccupied site. The risks are associated with the management of contractors undertaking surveillance, maintenance and any remediation work. As required by the CNSC licence, a contractor management program is in place to mitigate this risk. CNSC staff concluded Cameco satisfactorily maintained a conventional health and safety program that protected the health and safety of workers.

### 14. Cluff Lake

Cluff Lake was last reported on in the Regulatory Oversight Report for Uranium Mines and Mills in Canada: 2016; since then, there have been no significant changes to the site and the site remains stable.

The decommissioned Cluff Lake uranium mine and mill is located in northern Saskatchewan, approximately 75 kilometres south of Lake Athabasca and 30 kilometres east of the provincial border with Alberta. Owned and operated by AREVA Resources Canada Inc., (AREVA), now known as Orano Canada Inc., the Cluff Lake Project operated from 1981 to 2002. Following closure, the major decommissioning activities commenced and were largely completed within five years. In September 2013, the Cluff Lake Project reached a major milestone when they decommissioned the remaining camp residence and airstrip. Site occupancy was ceased, and access to the site is no longer controlled. Figure 14.1 provides an aerial view of the Cluff Lake area showing key components of the operation.

The former Cluff Lake Operation consisted of a central mill, above ground tailings management area (TMA), three open pits, two underground mines, associated waste rock piles, and site infrastructure including an airstrip and camp (figure 14.2).

As part of decommissioning activities, the Claude pit was completely filled in. The DJ/DJX and D pits were flooded and remain isolated from adjacent natural water bodies. Potentially problematic portions of the surface waste rock piles were placed into the pits, while the remainder of the surface waste rock was contoured, covered and revegetated. The portals and vents to the underground mines were closed and the TMA was contoured, covered and revegetated. All structures were dismantled and disposed of. Figure 14.3 shows the DJ and DJX pits with the Claude waste rock pile in the background.

In 2009, the CNSC issued AREVA a 10-year uranium mine decommissioning licence for Cluff Lake. The licence is valid until July 31, 2019. In 2017, AREVA completed the fourth year of campaign monitoring in compliance with its licence. There were no issues or concerns identified. The recovery of the site is proceeding as anticipated.

#### 14.1 Performance

For 2016 and 2017, CNSC staff were satisfied with AREVA’s performance in all relevant SCAs. AREVA’s performance over the reporting period of 2016 and 2017 was rated as “satisfactory” and the site continues to be stable, safe and well managed.

#### 14.2 Radiation protection

For 2016 and 2017, CNSC staff rated the radiation protection SCA as “satisfactory”.

Cluff Lake – Radiation protection ratings
2016 2017
SA SA
SA = satisfactory

AREVA’s radiation protection program is reflective of the low risk of radiation exposure at the site. Due to the nature of the site activities and mitigation measures in place, radiation doses to the workers and the public are well below the public dose limit of 1 mSv.

CNSC staff were satisfied with AREVA’s radiation protection program at Cluff Lake and will continue to monitor the effectiveness of the program in future inspections.

#### 14.3 Environmental protection

For 2016 and 2017, CNSC staff rated the environmental protection SCA as “satisfactory”.

Cluff Lake – Environmental protection ratings
2016 2017
SA SA
SA = satisfactory

The environmental monitoring program at Cluff Lake measures the quality of groundwater, surface water and air. Groundwater monitoring confirmed that aquatic life in nearby lakes is protected. Water quality in Island Lake, which received treated effluent from the tailings impoundment area during operations, is generally stable or improving as predicted.

AREVA monitors radon gas in remediated areas. CNSC staff reviewed the results and concluded that the radon concentrations are consistent with values measured in previous years and generally reflective of concentrations naturally occurring in northern Saskatchewan. In 2016 and 2017, CNSC staff were satisfied with the environmental monitoring at Cluff Lake and will continue to assess results to ensure that mitigation measures remain effective and stable.

In 2016 and 2017, CNSC staff reviewed the environmental performance and environmental risk assessment updates for Cluff Lake. CNSC staff concluded that the air, surface water and sediment quality were similar to that predicted in the Cluff Lake Decommissioning Project Comprehensive Study Report and are satisfied with the results.

For 2016 and 2017, CNSC staff were satisfied that AREVA had adequate measures in place to protect the public and the environment from residual releases from the Cluff Lake site.

##### Independent Environmental Monitoring Program

To complement ongoing compliance activities, the CNSC implements an Independent Environmental Monitoring Program (IEMP) to independently verify that all persons and the environment around licensed nuclear facilities are protected. The IEMP involves taking samples from public areas around the facilities, and measuring and analyzing the amount of radioactive and hazardous substances in those samples. In 2017, CNSC staff collected samples of radon in ambient air, lake water, fish (Northern Pike and Lake Whitefish), blueberries and Labrador tea at a reference station at Saskatoon Lake, which was not exposed to activities at the Cluff Lake site, and at two exposure stations at Sandy Lake and Cluff Lake. The results are available on the CNSC’s IEMP Web page. The IEMP results indicate that all persons and the environment in the vicinity of the Cluff Lake site are protected, and there are no health impacts as a result of site activities.

#### 14.4 Conventional health and safety

For 2016 and 2017, CNSC staff rated the conventional health and safety SCA as “satisfactory”.

Cluff Lake – Conventional health and safety ratings
2016 2017
SA SA
SA = satisfactory

AREVA maintained a conventional health and safety program to protect the health and safety of workers at the Cluff Lake site. This program is reflective of the low risk and unique challenges of the isolated location of the work. Prior to each sampling campaign, safety meetings were held between AREVA and consultants.

For 2016 and 2017, CNSC staff were satisfied with AREVA’s conventional health and safety program and will continue to monitor the program’s effectiveness.

### 15. Rayrock

Rayrock was last reported on in the Regulatory Oversight Report for Uranium Mines, Mills, Historic and Decommissioned Sites in Canada: 2015. Since then, there have been no significant changes to the site and the site has remained stable.

The Rayrock idle mine site was formerly a uranium mine and mill. It is located in the Northwest Territories, 74 kilometres northwest from the community of Behchoko (formerly the community of Rae) and 156 kilometres northwest of Yellowknife. Figure 15.1 presents an aerial view of the Rayrock idle mine site.

The uranium mine and mill operated from 1957 until 1959, when the site was abandoned. The site was then decommissioned and rehabilitated in 1996 by Indigenous and Northern Affairs Canada (INAC). A CNSC designated officer renewed INAC’s waste nuclear substance licence on June 30, 2017 for a period of 10 years (until June 30, 2027). Subsequently, CNSC staff issued a licence conditions handbook to provide guidance on the compliance strategy for the Rayrock mine site.

#### 15.1 Performance

For 2016 and 2017, CNSC staff were satisfied with INAC’s performance in the safety and control areas (SCAs) of environmental protection and conventional health and safety. For 2016, CNSC staff rated Rayrock’s performance in the radiation protection SCA as “below expectations” because the licensee lacked a documented radiation protection program. A specific program was established and this SCA was rated “satisfactory” in 2017. INAC’s performance over the reporting period of 2016 and 2017 has otherwise been stable and has met the requirements of the Nuclear Safety and Control Act NSCA and its associated regulations.

In 2016 and 2017, as part of ongoing monitoring and maintenance work, INAC undertook site stabilization activities. These activities include increasing site accessibility for the licensee and its contactors to ensure that maintenance activities can continue in a safe manner.

According to the CNSC’s risk-informed baseline inspection plan, Rayrock is subject to a minimum of one compliance inspection every three years. CNSC staff conducted an inspection in 2016. In 2017, CNSC staff reviewed INAC’s response to the findings from this inspection and are satisfied with INAC’s corrective actions.

#### 15.2 Radiation protection

For 2016, CNSC staff rated the radiation protection SCA “below expectations”. In 2017, this SCA was given a rating of “satisfactory”.

Rayrock – Radiation protection ratings
2016 2017
BE SA
BE = below expectations SA = satisfactory

While preparing for the 2016 inspection, CNSC staff became aware that the licensee had some good practices and elements of a radiation protection program in place, but that these were not consistently followed or formally documented in a single program as required by regulations. Because of the lack of a documented radiation protection program, CNSC staff rated this SCA as “below expectations” in 2016. Although there was no specific radiation protection program, this instance of non-compliance was considered low risk because of the nature of the site activities and existing mitigation measures. The licensee then submitted a radiation protection program for CNSC staff’sreview in late 2016, prior to the renewal of the Rayrock licence. For 2017, CNSC staff rated this SCA as “satisfactory” following the establishment of the radiation protection program. CNSC staff used onsite measurements to verify that radiation doses to the workers and the public were well below the public dose limit of 1 mSv.

CNSC staff will verify the program’s implemented in the next scheduled compliance inspection in 2019

#### 15.3 Environmental protection

For 2016 and 2017, CNSC staff rated the environmental protection SCA as “satisfactory”.

Rayrock – Environmental protection ratings
2016 2017
SA SA
SA = satisfactory
##### Assessment and monitoring

The Rayrock site is the subject of a long-term post-remediation monitoring program. Surface water quality monitoring is carried out every three years and radon and gamma monitoring is carried out every five years.

For 2016, CNSC staff’s inspection results confirmed INAC’s 2015 monitoring results and found the contaminant concentrations in waterbodies in and around the site were typically below maximum levels outlined in the Canadian Water Quality Guidelines for the Protection of Aquatic Life. However, there were some exceedances for aluminum, copper, and iron at some locations in onsite lakes. There was one exceedance of the water quality guidelines for uranium in Mill Lake, due to the presence of historic uranium mine tailings at the bottom of the lake.

There were no monitoring activities at the site in 2017, as the focus was on field activities and data collection to update the human health and environmental risk assessment for the site.

##### Environmental risk assessment

In 2017, INAC undertook a field program to collect additional data to support an updated human health and ecological risk assessment (HHERA), which it submitted in 2018. The updated HHERA is currently under review by CNSC staff, and the results will be used to support additional remediation activities and a revised post-remediation monitoring plan.

For 2016 and 2017, CNSC staff concluded that INAC had adequate measures in place at the Rayrock site to protect the public and the environment.

### 16. Port Radium

Port Radium was last reported on in the Regulatory Oversight Report for Uranium Mines and Mills in Canada: 2016. Since then, there have been no significant changes to the site and the site remains stable.

The Port Radium idle mine site is located in the Northwest Territories at Echo Bay on the eastern shores of Great Bear Lake, about 265 kilometres east of the Dene community of DÃ©line at the edge of the Arctic Circle (see figure 16.1).

The mine was in operation for 50 years, from 1932 to 1982. The site covers approximately 12 hectares and is estimated to contain 1.7 million tons of uranium and silver tailings. The site was partially decommissioned in 1984, according to the standards at that time. In 2006, the Government of Canada reached an agreement with the local community and completed the remediation of the site in 2007 under a CNSC waste nuclear substance licence granted to Indigenous and Northern Affairs Canada (INAC). On December 31, 2016, a CNSC designated officer renewed INAC’s licence for a period of 10 years (until December 31, 2026), in order to allow continued long-term maintenance and monitoring of the Port Radium site. In 2017, CNSC staff issued a licence conditions handbook to provide guidance on the compliance strategy for the Port Radium site.

#### 16.1 Performance

For 2016 and 2017, CNSC staff were satisfied with INAC’s performance in the environmental protection and conventional health and safety SCAs. For 2016, CNSC staff rated the radiation protection SCA as “below expectations” because of the lack of a documented radiation protection program. After a program was established, CNSC staff rated this SCA as “satisfactory” in 2017. INAC’s performance over the 2016 and 2017 reporting period has otherwise been stable and met the requirements of the NSCA and its associated regulations.

According to CNSC’s risk-informed baseline inspection plan, Port Radium is subject to a minimum of one compliance inspection every three years. CNSC staff conducted an inspection in 2016. In 2017, CNSC staff reviewed INAC’s response to the findings from this inspection and are satisfied with INAC’s corrective actions.

#### 16.2 Radiation protection

For the year 2016, CNSC staff rated the radiation protection SCA as “below expectations” while for 2017, CNSC staff rated the SCA as “satisfactory”.

Port Radium – Radiation protection ratings
2016 2017
BE SA
BE = below expectations SA = satisfactory

In preparation for the 2016 inspection, CNSC staff became aware that while the licensee had some good practices and elements of a radiation protection program in place, these were not consistently followed or formally documented in a single program, as required by regulations. Although there was no specific radiation protection program, this instance of non-compliance was considered low risk because of the nature of the site activities and existing mitigation measures. Through onsite measurements, CNSC staff verified that radiation doses to the workers and the public were well below the public dose limit of 1 mSv.

Since a radiation protection program is a regulatory requirement and the licensee lacked such a program in 2016, CNSC staff rated the radiation protection SCA as “below expectations” for that year. The licensee submitted a radiation protection program for CNSC staff review in late 2016, prior to the renewal of the Port Radium licence. CNSC staff rated this SCA as “satisfactory” in 2017, due to the establishment of a radiation protection program. CNSC staff will verify the program’s implementation in the next scheduled compliance inspection in 2019.

#### 16.3 Environmental protection

For 2016 and 2017, CNSC staff rated the environmental protection SCA as “satisfactory”.

Port Radium – Environmental protection ratings
2016 2017
SA SA
SA = satisfactory

INAC conducted water quality sampling in 2016; therefore measurements from that year form the basis of the CNSC’s environmental rating for this site. There were some elevated concentrations of several contaminants including arsenic, uranium, copper and zinc in onsite water bodies. These results were consistent with INAC’s historical monitoring data. Contaminants in nearby Great Bear Lake and Labine Bay were all below the maximum concentrations listed in Canadian Water Quality Guidelines for the Protection of Aquatic Life. INAC is in the process of updating its environmental monitoring plan; as such, no monitoring activities were undertaken in 2017.

For 2016 and 2017, CNSC staff were satisfied that INAC had adequate measures in place at the Port Radium site to protect the public and the environment.

### 17. Agnew Lake

Agnew Lake was last reported on in the Regulatory Oversight Report for Uranium Mines, Mills, Historic and Decommissioned Sites in Canada: 2015; since then, there have been no significant changes to the site and the site has remained stable.

The Agnew Lake mine is located about 25 kilometres northwest of Nairn Centre, Ontario (see figure 17.1). The uranium mine site was decommissioned and monitored by Kerr Addison Mines from 1983 until 1988. The site was then turned over to the Province of Ontario in the early 1990s. On January 20, 2011, the CNSC issued Ontario’s Ministry of Northern Development and Mines (MNDM) a waste nuclear substance licence for Agnew Lake. The licence is valid until January 31, 2021. For the foreseeable future, the site is expected to remain under long-term monitoring and maintenance.

#### 17.1 Performance

For 2016 and 2017, CNSC staff were satisfied with MNDM’s performance in the safety and control areas (SCAs) of environmental protection and conventional health and safety. For 2016, CNSC staff rated the radiation protection SCA as “below expectations” because the licensee lacked a documented radiation protection program. After interim measures were established and significant improvements were made to onsite radiation protection, this SCA was rated “satisfactory” in 2017. MNDM’s performance over the reporting period has otherwise been stable and met the requirements of the NSCA and its associated regulations.

During a 2015 inspection, CNSC staff found that sections of the tailings areas were exposed where the TMA cover had degraded, and that some locations measured dose rates of greater than 1 μSv/h. In 2016, MNDM conducted a gamma dose-rate survey and public dose assessment of the Agnew Lake TMA and found that incremental dose rates ranged from 0 to 8.1 μSv/h, with an average of 1.085 μSv/h.

Repair to the cover of the TMA is planned, and MNDM has proposed to add niobium ore and tailings that are classified as naturally occurring radioactive material from the former Beaucage Mine near North Bay to cover these exposed tailings at Agnew Lake. MNDM has proposed that the placement of the niobium waste will provide shielding for the existing tailings, and that the soil cover over the niobium waste will prevent contact with the niobium waste and reduce gamma doses to background levels.

#### 17.2 Radiation protection

For the year 2016, CNSC staff rated the radiation protection SCA as “below expectations” while for 2017, CNSC staff rated the SCA as “satisfactory”.

Agnew Lake – Radiation protection ratings
2016 2017
BE SA
BE = below expectations SA = satisfactory

In preparation for the 2016 inspection, CNSC staff became aware that while the licensee had some good practices and elements of a radiation protection program in place, these were not consistently followed or formally documented in a single program, as required by regulations. Although there was no radiation protection program, this instance of non-compliance was considered low risk because of the static state of the site, infrequent access to the site and results of a gamma dose-rate survey. CNSC staff have communicated their expectations and the licensee has been receptive and incorporated interim measures to address identified issues.

In 2017, CNSC staff rated this SCA as “satisfactory”, based on a number of improvements to the site’s radiation protection program. In 2017, MNDM also installed two new radiation warning signs on the west end and east end of the Agnew Lake TMA to inform the public of potential radiation hazards onsite. CNSC staff observed hunting blinds erected near the TMA in 2016 and 2017; MNDM posted signage on the hunting blinds alerting the owners of radon risks and informing them that the blinds would be removed. MNDM has since removed these hunting blinds from this area. MNDM conducted a public dose assessment of the Agnew Lake TMA, confirming that the estimated dose to the public was below the regulatory limit of 1 mSv/year.

The licensee has committed to submitting a consolidated radiation protection program in support of its request for a licence amendment to support upgrades to its tailings cover.

#### 17.3 Environmental protection

For 2016 and 2017, CNSC staff rated the environmental protection SCA as “satisfactory”.

Agnew Lake – Radiation protection ratings
2016 2017
SA SA
SA = satisfactory
##### Assessment and monitoring

MNDM measures contaminant concentrations in surface water at several locations around the site. The last reported measurements were submitted to the CNSC in 2017. CNSC staff reviewed the results and found that contaminant concentrations in water bodies in and around the site were below the maximum concentrations specified in Ontario’s Surface Water Quality Objectives.

For 2016 and 2017, CNSC staff were satisfied that MNDM had adequate measures in place at Agnew Lake to protect the public and the environment from releases from the site.

### 18. Bicroft

Bicroft was last reported on in the Regulatory Oversight Report for Uranium Mines, Mills, Historic and Decommissioned Sites in Canada: 2015; since then, there have been no significant changes to the site and the site has remained stable.

The Bicroft tailings storage facility, owned and operated by Barrick Gold Corporation, is located on the south side of Highway 118, approximately 2 kilometres west of Cardiff, Ontario. On December 14, 2010, the CNSC issued Barrick Gold a waste nuclear substance licence for Bicroft; this licence is valid until February 28, 2021. For the foreseeable future, the site is expected remain under long‑term monitoring and maintenance (see figure 18.1).

The Bicroft facility was constructed to contain tailings from mining operations that were carried out at the nearby Bicroft mine, which operated from 1956 to 1962. The uranium tailings stored in the Bicroft tailings storage site resulted from the processing of low-grade uranium ore at the Bicroft mine. Remediation work included vegetation of exposed tailings in 1980 and upgrading of dams in 1990 and 1997. Areas of the site are now used for occasional recreational use by the local snowmobile club.

#### 18.1 Performance

For 2016 and 2017, CNSC staff were satisfied with Barrick Gold Corporation’s performance in the safety and control areas (SCAs) of radiation protection, environmental protection and conventional health and safety at the Bicroft site. The licensee’s performance over the 2016 and 2017 reporting period has been stable and met the requirements of the Nuclear Safety and Control Act and its associated regulations.

In 2016 and 2017, CNSC staff found that the site was well managed and maintained, and that satisfactory environmental protection measures and procedures were in place; for example, the licensee’s continued maintenance improvements by removing vegetation on certain dams and beaver cuttings to ensure the overall integrity of the dams.

#### 18.2 Radiation protection

For 2016 and 2017, CNSC staff rated the radiation protection SCA as “satisfactory”.

Bicroft – Radiation protection ratings
2016 2017
SA SA
SA = satisfactory

There were no year-round workers at the Bicroft site during 2016 and 2017, but licensee staff and contractors were onsite for limited periods of time for monitoring, mitigation activities and inspections. Based on the outcome of CNSC staff inspections and work practices, CNSC staff concluded that Barrick Gold has been effectively controlling radiation doses at the Bicroft site.

Barrick Gold’s radiation protection program reflects the low risk of radiation exposure at the site. Because of the nature of the site activities and mitigation measures in place, radiation doses to the workers and the public were well below the public dose limit of 1 mSv in 2016 and 2017.

#### 18.3 Environmental protection

For 2016 and 2017, CNSC staff rated the environmental protection SCA as “satisfactory”.

Bicroft – Environmental protection ratings
2016 2017
SA SA
SA = satisfactory

Water quality sampling is carried out every five years at the site. Sampling last occurred during the 2015 field season. Barrick Gold has an environmental sampling program for the Bicroft site and sampling results were provided to the CNSC in its 2015 annual report.

CNSC staff reviewed the Bicroft site’s 2016 dam safety review and provided recommendations to enhance the dam safety program. The licensee responded to these recommendations and CNSC staff are currently reviewing the responses.

For 2016 and 2017, CNSC staff remained satisfied that Barrick Gold Corporation had adequate measures in place at the Bicroft site to protect the public and the environment.

### 19. Dyno

Dyno was last reported on in the Regulatory Oversight Report for Uranium Mines, Mills, Historic and Decommissioned Sites in Canada: 2015; since then, there have been no significant changes to the site and the site has remained stable.

The Dyno closed mine property is located at Farrel Lake, about 30 kilometres southwest of Bancroft, Ontario. The mill circuit at Dyno operated between 1958 and 1960. The property consists of an abandoned, sealed underground uranium mine; a mill, which has been demolished; capped openings; a tailings area; one dam with a toe berm; and various roadways (see figure 19.1). The site is managed and monitored by EWL Management Ltd. (EWL), which holds a CNSC waste nuclear substance licence for Dyno. The licence was issued on September 23, 2009 and is valid until January 31, 2019, and CNSC staff are currently reviewing the licensee’s renewal application. The site is expected remain under long-term monitoring and maintenance for the foreseeable future.

#### 19.1 Performance

For 2016 and 2017, CNSC staff were satisfied with EWL’s performance in the safety and control areas (SCAs) of radiation protection, environmental protection and conventional health and safety. Performance over the reporting period of 2016 and 2017 at the Dyno site was stable and met the requirements of the Nuclear Safety and Control Act and its associated regulations.

During baseline compliance inspections in 2016 and 2017, CNSC staff found that the site was well managed and maintained. There were satisfactory environmental protection measures and procedures in place.

#### 19.2 Radiation protection

For 2016 and 2017, CNSC staff rated the radiation protection SCA as “satisfactory”.

Dyno – Radiation protection ratings
2016 2017
SA SA
SA = satisfactory

There were no year-round workers at the Dyno site during 2016 and 2017, but licensee staff and contractors were onsite for limited periods of time for monitoring, mitigation activities and inspections. Gamma dose rates around the site are also very low. Based on the low exposure times and dose rates, and the outcome of CNSC staff inspections and work practices, CNSC staff concluded that EWL is effectively controlling radiation doses to workers and the public.

The licensee’s radiation protection program is reflective of the low risk of radiation exposure at the site. Due to the nature of the site activities and mitigation measures in place, radiation doses to the workers and the public are well below the public dose limit of 1 mSv.

#### 19.3 Environmental protection

For 2016 and 2017, CNSC staff rated the environmental protection SCA as “satisfactory”.

Dyno – Environmental protection ratings
2016 2017
SA SA
SA = satisfactory

The Dyno site has an environmental sampling program. EWL provided sampling results to the CNSC in its 2016 and 2017 annual reports. Water quality sampling is carried out every two years at the site and was last conducted during the 2016 field season. CNSC staff reviewed the results and concluded that all locations for uranium surface water samples met provincial water quality objectives in 2016 and 2017.

The Dyno site is also the subject of a geotechnical monitoring and inspection program for its tailings dam. In 2016, CNSC staff reviewed the geotechnical report and found that the dam met the safety standards in the Canadian Dam Association’s Dam Safety Guidelines. CNSC staff are planning a geotechnical inspection at the Dyno site in fall 2018.

For 2016 and 2017, CNSC staff were satisfied that EWL had adequate measures in place at the Dyno site to protect the public and the environment.

### 20. Elliot Lake

Elliot Lake was last reported on in the Regulatory Oversight Report for Uranium Mines and Mills in Canada: 2016; since then there have been no significant changes to the site and the site has remained stable.

Rio Algom Limited (RAL) is the owner and licensee of nine decommissioned uranium mines in the Elliot Lake area of northeastern Ontario – Stanleigh, Quirke, Panel, Spanish, American, Milliken, Lacnor, Buckles and Pronto – as well as some peripheral areas. Figure 20.1 shows a spillway at one of these decommissioned sites (Panel mine site).

The mine sites and associated tailings management areas (TMAs) are managed under one CNSC waste facility operation licence, which is of indefinite term. The sites have all been decommissioned and the TMAs are in the long-term care and maintenance phase. RAL conducts site-specific and regional environmental monitoring programs, operates the effluent treatment plants, inspects and maintains the sites in the Elliot Lake area. The long-term plan for these sites is to reach a state where water treatment is no longer required and reliance on physical works can be reduced.

In 2017 and as part of the Regulatory Oversight Report for Uranium Mines and Mills in Canada: 2016, CNSC staff provided the Commission with a status update on environmental performance (CMD-17-M47, appendix K) at the Elliot Lake historic mine and tailings management sites, as well on as the separately licensed Denison and Stanrock properties. In that update, CNSC staff also provided a summary of their review of the licensee’s State of the Environment Report for 2010 to 2014.

#### 20.1 Performance

CNSC staff conducted annual compliance inspections in 2016 and 2017 and found that the sites were in good condition and well managed by the licensee. No enforcement actions were issued during this period as the result of these inspections.

For 2016 and 2017, CNSC staff were satisfied with RAL’s performance in the safety and control areas (SCAs) of radiation protection, and conventional health and safety.

RAL’s performance in the environmental protection SCA was rated as “satisfactory” in 2016, but as “below expectations” for 2017 because of radium releases from the Stanleigh effluent treatment plant that exceeded the allowable limits specified in the licence. This exceedance was reported to the Commission on January 17, 2018. As a result of this exceedance, the CNSC issued an information request pursuant to subsection 12(2) of the General Nuclear Safety and Control Regulations. This request required RAL to conduct an analysis of past corrective actions and to develop a new corrective action plan to address the exceedance. RAL was also required to perform an assessment of best available technology economically achievable (BATEA), and to provide a timeline for implementation of the corrective action plan and the return of radium levels to levels in compliance with the licence conditions.

#### 20.2 Radiation protection

As a result of CNSC staff reviews of the licensee’s radiation protection data for 2016 and 2017, CNSC staff rated the radiation protection SCA as “satisfactory”.

Elliot Lake – Radiation protection ratings
2016 2017
SA SA
SA = satisfactory

CNSC staff verified that there were no gamma doses recorded for NEWs at the RAL properties using either the thermoluminescent dosimeter or optically stimulated luminescence dosimeter gamma badges in 2016 and 2017.

#### 20.3 Environmental protection

For 2016, CNSC staff rated the environmental protection SCA as “satisfactory”. In 2017, the release to the environment of radium in treated water from the Stanleigh effluent treatment plant was above the monthly licence limit for the month of December. This release resulted in a rating of “below expectations”.

Elliot Lake – Environmental protection ratings
2016 2017
SA BE
BE = below expectations SA = satisfactory
##### Assessment and monitoring

RAL has an extensive water treatment and monitoring program at all licensed TMAs. RAL’s monitoring program is coordinated with Denison Mines Inc. and consists of three integrated aspects: the TMA Operational Monitoring Program, the Source Area Monitoring Program and the Serpent River Watershed Monitoring Program. Data from these programs is reported to the CNSC monthly and annually, and is compiled into a State of the Environment report every five years.

##### Licence limit exceedance for radium at Stanleigh TMA

RAL reported an exceedance of the monthly average discharge limit for radium-226 at the Stanleigh effluent discharge location for December 2017. The reported value for December 2017 was 0.415 Bq/L, and the allowable monthly average limit in the licence is 0.37 Bq/L. This limit is based on the Metal Mining Effluent Regulations and is protective of the environment. RAL notified the CNSC of the exceedance through the duty officer on January 11, 2018, and also notified the Ontario Ministry of the Environment and Climate Change. The Commission was notified of the exceedance on January 17, 2018.

Despite the exceedance, radium-226 concentrations in the undiluted effluent continued to be below the suggested parameters (0.5 Bq/L) in Health Canada’s Guidelines for Canadian Drinking Water Quality. CNSC staff requested that RAL carry out a toxicity test of the effluent. RAL confirmed that all tested fish survived when exposed to effluent. Concentrations of radium-226 in the receiving environment also met drinking water standards and were below levels considered to pose a risk to aquatic biota. Based on the preliminary information, CNSC staff concluded there were no radiological impacts to members of the public or the environment as a result of this exceedance. As reported to the Commission in December 2017 in the Regulatory Oversight Report for Uranium Mines and Mills in Canada: 2016 (CMD 17-M47), all annual mean concentrations of constituents of concern in the receiving environment, including radium-226, were below the parameters in the Canadian Council of Ministers of the Environment’s Canadian Environmental Quality Guidelines and in Health Canada’s Guidelines for Canadian Drinking Water Quality.

Prior to the licence limit exceedance in December 2017, RAL had also reported an action level exceedance for radium-226 in November 2017. RAL is implementing measures to control radium-226 concentrations and to understand the cause of the exceedances. These measures include limiting flow, assessing the impact of settling times, and adding preformed barite as a treatment measure. CNSC staff have been continuing ongoing communication with RAL regarding the progress of this work.

As requested by CNSC staff and to ensure continued protection of the environment, the licensee also implemented supplementary monitoring protocols, which include toxicity testing of the effluent at the discharge location, and additional downstream monitoring.

CNSC staff issued a request pursuant to subsection 12(2) of the General Nuclear Safety and Control Regulations to RAL on January 22, 2018. This request included the steps required to modify the treatment facility, in order to bring radium-226 concentrations down to levels below the applicable limits; timelines for implementing these changes; and an updated assessment to ensure that the environment would remain protected. In accordance with this 12(2) request, RAL provided a corrective action plan on April 12, 2018, which outlined the proposed measure to correct the exceedance and a timeline. However, the request was left open pending receipt of all requested information from the licensee. CNSC staff plan to review the information once submitted and to consider if additional enforcement action would be required.

CNSC staff confirmed that there were no radiological impacts to members of the public or the environment as a result of this regulatory exceedance. However, CNSC staff have increased their level of compliance oversight, and will continue to do so until the situation has stabilized.

### 21. Denison and Stanrock

Denison and Stanrock were last reported on in the Regulatory Oversight Report for Uranium Mines and Mills in Canada: 2016; since then, there have been no significant changes to the sites and the sites have remained stable.

Denison Mines Inc. is the licensee for the two closed uranium mines of Denison and Stanrock in the Elliot Lake area of northeastern Ontario. The Denison and Stanrock sites are licensed individually under separate licences with indefinite licence periods.

The licences cover the physical works, such as dam structures, effluent treatment plants and fencing, associated with the decommissioned mine and mill tailings. The licensee conducts onsite inspection programs and ensures that local and area-wide environmental monitoring programs are in place (see figure 21.1).

In 2017, CNSC staff provided the Commission with a status update on environmental performance at the Elliot Lake historic mine and tailings management sites. This update included sites under both the Denison and Stanrock licences, as well as the properties managed by Rio Algom (CMD‑17-M47, appendix K). In that update, CNSC staff also provided a summary of their review of the licensee’s State of the Environment Report for 2010 to 2014.

The Denison and Stanrock mine sites have been decommissioned and there are no mining or milling structures remaining. The tailings management areas (TMAs) are in the long-term care and maintenance phase, which includes water treatment, source and watershed monitoring. The Denison mine site contains two TMAs that are covered by water and contain a total of 63 million tonnes of uranium mine tailings. The Stanrock site is a dry TMA with a head pond upstream of Dam A and contains 6 million tonnes of uranium mine tailings.

#### 21.1 Performance

For 2016 and 2017, CNSC staff were satisfied with the licensee’s performance in the safety and control areas (SCAs) of radiation protection, environmental protection, and conventional health and safety. The licensee’s performance at the Denison and Stanrock sites has been stable and met requirements of the Nuclear Safety and Control Act and its associated regulations during 2016 and 2017.

In 2016 and 2017, CNSC staff inspected the sites and found they were well managed and had no compliance issues. CNSC staff confirmed the dams and associated structures were in good operating condition and appeared well maintained. Effluent water quality at all discharge locations was in compliance with licence limits.

#### 21.2 Radiation protection

For 2016 and 2017, CNSC staff rated the radiation protection SCA as “satisfactory”.

Denison and Stanrock – Radiation protection ratings
2016 2017
SA SA
SA = satisfactory

CNSC staff verified that there were no gamma doses recorded for nuclear energy workers in 2016 and 2017 at the Denison and Stanrock properties using either thermoluminescent dosimeters or optically stimulated luminescence dosimeter gamma badges.

#### 21.3 Environmental protection

For 2016 and 2017, CNSC staff rated the environmental protection SCA as “satisfactory”. An environmental protection program was satisfactorily maintained at the Denison and Stanrock facilities to ensure that the environment was protected.

Denison and Stanrock – Environmental protection ratings
2016 2017
SA SA
SA = satisfactory
##### Effluent and emissions

CNSC staff reviewed air emissions monitoring results for radon annual averages for 2016 and 2017 and were satisfied with the results at the Denison and Stanrock facilities.

CNSC staff verified that the effluent water quality for constituents of potential concern consistently met discharge criteria at all TMAs.

For 2016 and 2017, CNSC staff were satisfied that adequate measures were in place to protect the public and the environment at the Denison and Stanrock sites.

## Appendix A: Facility licensing information

Table A-1 presents CNSC licensing information for the operating uranium and mills discussed in this report.

Table A-1: Operating uranium mines and mills – Licensing information
Licensee / site / licence # Licence effective Last licence amendment Licence expiration

AREVA Resources Canada Inc.

McClean Lake Operation

Uranium mine and mill operating licence

UMOL-MINEMILL-McCLEAN.00/2027

July 1, 2017 - June 30, 2027

Cameco Corporation

Cigar Lake Operation

Uranium mine operating licence

UML-MINE-CIGAR.00/2021

July 1, 2013 - June 30, 2021

Cameco Corporation

Key Lake Operation

Uranium mill operating licence

UMLOL-MILL-KEY.00/2023

November 1, 2013 - October 31, 2023

Cameco Corporation

Rabbit Lake Operation

Uranium mine and mill operating licence

UMOL-MINEMILL-RABBIT.00/2023

November 1, 2013 - October 31, 2023

Cameco Corporation

McArthur River Operation

Uranium mine operating licence

UMOL-MINE-McARTHUR.00/2023

November 1, 2013 - October 31, 2023

Table A-2 presents CNSC licensing information for the historic and decommissioned sites discussed in this report.

Table A-2: Historic and decommissioned sites – Licensing information
Licensee / site / licence # Licence effective Last licence amendment Licence expiration

Saskatchewan Research Council

Gunnar Legacy Uranium Mine Site

WNSL-W5-3151.00/2024

January 14, 2015 - November 30, 2024

Saskatchewan Research Council

Lorado Tailings Management Site

WNSL-W5-3150.00/2023

April 29, 2014 - April 30, 2023

Ontario Ministry of Environment

Deloro Mine Site

WNSL-W1-3301.00/2022

November 1, 2017 - October 31, 2022

Cameco Corporation

Beaverlodge Mine and Mill

WFOL-W5-2120.0/2023

June 1, 2013 - May 31, 2023

AREVA Resources Canada Inc.

Cluff Lake Mine and Mill

UMDL-MINEMILL-CLUFF.00/2019

August 1, 2009 - July 31, 2019

Indigenous and Northern Affairs Canada

Rayrock Idle Mine Site

WNSL-W5-3208.0/2027

June 27, 2017 - June 30, 2027

Indigenous and Northern Affairs Canada Port Radium Idle Mine Site

WNSL-W5-3207.0/2026

January 1, 2017 - December 31, 2026

Ontario Ministry of Northern Development and Mines

Agnew Lake Tailings Management Area

WNSL-W1-3102.3/2021

January 20, 2011 December 18, 2012 January 31, 2021

EWL Management Ltd.

Madawaska Decommissioned Mines and Tailings Management Site

WNSL-W5-3100.1/2021

July 4, 2011 December 18, 2012 July 31, 2021

Barrick Gold Corporation

Bicroft Tailings Storage Facility

WNSL-W5-3103.1/2021

December 14, 2010 February 24, 2011 February 28, 2021

EWL Management Ltd.

Dyno Idle Mine Site

WNSL-W5-3101.4/2019

September 23, 2009 July 31, 2013 January 31, 2019

Rio Algom Limited

Elliot Lake Historic Sites Facility

WFOL-W5-3101.03/indf

January 1, 2006 June 7, 2007 Indefinite

Denison Mines Inc.

Denison Mining Facility

UMDL-MINEMILL-DENISON-.01/indf

October 16, 2002 December 15, 2004 Indefinite

Denison Mines Inc.

Stanrock Mining Facility

UMDL-MINEMILL-STANROCK-.02/indf

October 16, 2002 December 15, 2004 Indefinite

There were no changes to the licence conditions handbooks for historic and decommissioned sites during 2016 and 2017.

Table A-3 presents changes made during 2017 to the licence conditions handbooks of the operating uranium mines and mills discussed in this report.

Table A-3: Uranium mines and mills – Licence conditions handbook changes, 2017
Licensee / sites / licence # Licence conditions handbook revision Summary of changes Effective date

AREVA Resources Canada Inc.

McClean Lake Operation

UMOL-MINEMILL-McCLEAN.00/2027

4
• Section G.1: Added text for disposal of tailings up to 448 metres above sea level
• Section 4.1: Moved text related to ERA from the safety analysis SCA to the environmental protection SCA
• Section 9.2: Added authorized effluent discharge limits
• General: Updated licence documents, licensing basis and guidance references and, formatted the LCH to the latest template
October 6, 2017

## Appendix B: List of Inspections by Facility and Safety and Control Area

Table B-1 presents information on inspections that took place during 2017 at operating mines and mills, and during 2016 and 2017 at historic and decommissioned sites.

Table B-1: Inspections by facility and safety and control area
Facility Safety and control area(s) evaluated Date that inspection report was issued
Cigar Lake Operation Environmental protection, radiation protection, conventional health and safety, operating performance, fitness for service March 6, 2017
Safety analysis May 5, 2017
Radiation protection July 19, 2017
Operating performance, environmental protection, radiation protection, physical design, fitness for service, packaging and transport October 20, 2017
Waste management, radiation protection, packaging and transport, conventional health and safety, human performance management December 8, 2017
Operating performance, packaging and transport January 9, 2018
McArthur River Operation Human performance management May 8, 2017
Environmental protection, waste management, safety analysis, conventional health and safety, radiation protection April 26, 2017
Safety analysis August 14, 2017
Conventional health and safety, human performance management September 25, 2017
Conventional health and safety, human performance management, radiation protection November 7, 2017
Packaging and transport December 11, 2017
Rabbit Lake Operation Safety analysis March 14, 2017
Management system, human performance management July 11, 2017
Radiation protection, operating performance, fitness for service, emergency management and fire protection August 31, 2017
Waste management, environmental protection September 7, 2017
Physical design, operating performance, radiation protection, conventional health and safety, packaging and transport January 10, 2018
Radiation protection, environmental protection, conventional health and safety January 9, 2018
Key Lake Operation Fitness for service, conventional health and safety, environmental protection, radiation protection March 31, 2017
Management system July 26, 2017
Conventional health and safety October 6, 2017
Radiation protection October 20, 2017
Packaging and transport December 15, 2017
Fitness for service, operating performance, conventional health and safety, safety analysis January 9, 2018
McClean Lake Operation Radiation protection April 19, 2017
Management system, human performance management, operating performance, conventional health and safety, environmental protection, waste management, radiation protection July 5, 2017
Management systems, radiation protection, conventional health and safety July 18, 2017
Fitness for service September 8, 2017
Physical design, conventional health and safety, environmental protection November 3, 2017
Operating performance January 26, 2018
Gunnar Operating performance, radiation protection, conventional health and safety, emergency management and fire protection, January 25, 2017
Radiation protection, conventional health and safety, environmental protection, physical design, waste management, management system October 30, 2017
Lorado Radiation protection, conventional health and safety, environmental protection, physical design January 16, 2017
Fitness for service, radiation protection, environmental protection, waste management November 6, 2017
Deloro Radiation protection, environmental protection, conventional health and safety May 17, 2017
Management system, fitness for service, physical design, radiation protection, conventional health and safety, waste management, environmental protection March 23, 2018
Madawaska Radiation protection, environmental protection, conventional health and safety May 5, 2016
Beaverlodge Operating performance, public information and disclosure, radiation protection, conventional health and safety, environmental protection July 18, 2017
Cluff Lake Operating performance, conventional health and safety, environmental protection, radiation protection, other: public information and disclosure October 17, 2017
Rayrock Operating performance, radiation protection, conventional health and safety October 14, 2016
Port Radium Operating performance, radiation protection, conventional health and safety October 14, 2016
Agnew Lake Conventional health and safety, radiation protection, environmental protection May 26, 2017
Conventional health and safety, radiation protection, environmental protection February 1, 2018
Bicroft Conventional health and safety, radiation protection, fitness for service, security August 18, 2016
Conventional health and safety, radiation protection, fitness for service, security July 20, 2017
Dyno Conventional health and safety, radiation protection, fitness for service, security August 31, 2016
Conventional health and safety, radiation protection, environmental protection, fitness for service, security August 8, 2017
Elliot Lake Conventional health and safety, radiation protection February 14, 2018
Environmental protection July 28, 2017
Denison and Stanrock Conventional health and safety, radiation protection, environmental protection, February 14, 2018
Conventional health and safety, radiation protection, environmental protection, fitness for service, security September 26, 2016

## Appendix C: Safety and Control Area Definitions

The CNSC evaluates how well licensees meet regulatory requirements and CNSC performance expectations for programs in 14 safety and control areas (SCAs). The SCAs are grouped into three functional areas: management, facility and equipment, and core control processes.

Table C-1: Definitions of safety and control areas
Functional area Safety and control area Definition Specific areas
Management Management system Covers the framework that establishes the processes and programs required to ensure an organization achieves its safety objectives, continuously monitors its performance against these objectives, and fosters a healthy safety culture.
• Management system
• Organization
• Performance assessment, improvement and management review
• Operating experience (OPEX)
• Change management
• Safety culture
• Configuration management
• Records management
• Management of contractors
• Business continuity
Human performance management Covers activities that enable effective human performance through the development and implementation of processes that ensure a sufficient number of licensee personnel are in all relevant job areas and have the necessary knowledge, skills, procedures and tools in place to safely carry out their duties.
• Human performance program
• Personnel training
• Personnel certification
• Initial certification examinations and requalification tests
• Work organization and job design
• Fitness for duty
Operating performance Includes an overall review of the conduct of the licensed activities and the activities that enable effective performance.
• Conduct of licensed activity
• Procedures
• Reporting and trending
• Outage management performance
• Safe operating envelope
• Severe accident management and recovery
• Accident management and recovery
Facility and equipment Safety analysis Covers maintenance of the safety analysis that supports the overall safety case for the facility. Safety analysis is a systematic evaluation of the potential hazards associated with the conduct of a proposed activity or facility and considers the effectiveness of preventive measures and strategies in reducing the effects of such hazards.
• Deterministic safety analysis
• Hazard analysis
• Probabilistic safety analysis
• Criticality safety
• Severe accident analysis
• Management of safety issues (including research and development programs)
Physical design Relates to activities that impact the ability of structures, systems and components to meet and maintain their design basis given new information arising over time and taking changes in the external environment into account.
• Design governance
• Site characterization
• Facility design
• Structure design
• System design
• Component design
Fitness for service Covers activities that impact the physical condition of structures, systems and components to ensure that they remain effective over time. This area includes programs that ensure all equipment is available to perform its intended design function.
• Equipment fitness for service/equipment performance
• Maintenance
• Structural integrity
• Aging management
• Chemistry control
• Periodic inspection and testing
Core control processes Radiation protection Covers the implementation of a radiation protection program in accordance with the Radiation Protection Regulations. The program must ensure that contamination levels and radiation doses received by individuals are monitored, controlled and maintained as low as reasonably achievable (ALARA).
• Application of the ALARA principle
• Worker dose control
• Radiation protection program performance
• Radiological hazard control
• Estimated dose to public
Conventional health and safety Covers the implementation of a program to manage workplace safety hazards and to protect personnel and equipment.
• Performance
• Practices
• Awareness
Environmental protection Covers programs that identify, control and monitor all releases of radioactive and hazardous substances and effects on the environment from facilities or as the result of licensed activities.
• Effluent and emissions control (releases)
• Environmental management system
• Assessment and monitoring
• protection of the public
• environmental risk assessment
Emergency management and fire protection Covers emergency plans and emergency preparedness programs that exist for emergencies and for non-routine conditions. This area also includes any results of participation in exercises.
• Conventional emergency preparedness and response
• Nuclear emergency preparedness and response
• Fire emergency preparedness and response
Waste management Covers internal waste-related programs that form part of the facilityâ€™s operations up to the point where the waste is removed from the facility to a separate waste management facility. This area also covers the planning for decommissioning.
• Waste characterization
• Waste minimization
• Waste management practices
• Decommissioning plans
Core control processes Security Covers programs required to meet security requirements stipulated in the regulations, the licence, orders or expectations for the facility or activity.
• Facilities and equipment
• Response arrangements
• Security practices
• Drills and exercises
Safeguards and non-proliferation Covers programs and activities required to meet obligations of the Canada/International Atomic Energy Agency (IAEA) safeguards agreements, as well as all other measures arising from the Treaty on the Non-Proliferation of Nuclear Weapons.
• Nuclear material accountancy and control
• Access and assistance to the International Atomic Energy Agency
• Operational and design information
• Safeguards equipment, containment and surveillance
• Import and export
Packaging and transport Programs that cover the safe packaging and transport of nuclear substances to and from the licensed facility.
• Package design and maintenance
• Packaging and transport
• Registration for use
Other matters of regulatory interest
• Environmental assessments
• CNSC consultation – Indigenous communities
• CNSC consultation – other
• Cost recovery
• Financial guarantees
• Improvement plans and significant future activities
• Licensee public information program
• Nuclear liability insurance

## Appendix D: Safety and Control Area Rating Methodology

Performance ratings used in this report are defined as follows:

Fully satisfactory (FS)

Safety and control measures implemented by the licensee are highly effective. In addition, compliance with regulatory requirements is fully satisfactory, and compliance within the safety and control area or specific area exceeds requirements and Canadian Nuclear Safety Commission (CNSC) expectations. Overall, compliance is stable or improving, and any problems or issues that arise are promptly addressed.

Satisfactory (SA)

Safety and control measures implemented by the licensee are sufficiently effective. In addition, compliance with regulatory requirements is satisfactory. Compliance within the safety and control area or specific area meets requirements and CNSC expectations. Any deviation is only minor, and any issues are considered to pose a low risk to the achievement of regulatory objectives and the CNSC’s expectations. Appropriate improvements are planned.

Below expectations (BE)

Safety and control measures implemented by the licensee are marginally ineffective. In addition, compliance with regulatory requirements falls below expectations. Compliance within the safety and control area or specific area deviates from requirements or CNSC expectations to the extent that there is a moderate risk of ultimate failure to comply. Improvements are required to address identified weaknesses. The licensee or applicant is taking appropriate corrective action.

Unacceptable (UA)

Safety and control measures implemented by the licensee are significantly ineffective. In addition, compliance with regulatory requirements is unacceptable and is seriously compromised. Compliance within the overall safety and control area or specific area is significantly below requirements or CNSC expectations or there is evidence of overall non-compliance. Without corrective action, there is a high probability that the deficiencies will lead to an unreasonable risk. Issues are not being addressed effectively, no appropriate corrective measures have been taken, and no alternative plan of action has been provided. Immediate action is required.

## Appendix E: Safety and Control Area Ratings

Tables E-1 to E-10 present CNSC staff ratings for safety and control area at the facilities discussed in the report, for the years 2013 to 2017, as applicable.

Abbreviations used are as follows:

• FS: Fully satisfactory
• SA: Satisfactory
• UA: Unacceptable
• N/A: Not applicable
Table E-1: Safety and control area ratings, Cigar Lake Operation, 2013–17
Safety and control area 2013 2014 2015 2016 2017
Management system SA SA SA SA SA
Human performance management SA SA SA SA SA
Operating performance SA SA SA SA SA
Safety analysis SA SA SA SA SA
Physical design SA SA SA SA SA
Fitness for service SA SA SA SA SA
Radiation protection SA SA SA SA SA
Conventional health and safety FS SA SA SA SA
Environmental protection SA SA SA SA SA
Emergency management and fire protection SA SA SA SA SA
Waste management SA SA SA SA SA
Security SA SA SA SA SA
Safeguards and non-proliferation SA SA SA SA SA
Packaging and transport SA SA SA SA SA
Table E-2: Safety and control area ratings, McArthur River Operation, 2013–17
Safety and control area 2013 2014 2015 2016 2017
Management system SA SA SA SA SA
Human performance management SA SA SA SA SA
Operating performance SA SA SA SA SA
Safety analysis SA SA SA SA SA
Physical design SA SA SA SA SA
Fitness for service SA SA SA SA SA
Radiation protection SA SA SA SA SA
Conventional health and safety SA SA SA SA SA
Environmental protection SA SA SA SA SA
Emergency management and fire protection SA SA SA SA SA
Waste management SA SA SA SA SA
Security SA SA SA SA SA
Safeguards and non-proliferation SA SA SA SA SA
Packaging and transport SA SA SA SA SA
Table E-3: Safety and control area ratings, Rabbit Lake Operation, 2013–17
Safety and control area 2013 2014 2015 2016 2017
Management system SA SA SA SA SA
Human performance management SA SA SA SA SA
Operating performance SA SA SA SA SA
Safety analysis SA SA SA SA SA
Physical design SA SA SA SA SA
Fitness for service SA SA SA SA SA
Radiation protection SA SA SA SA SA
Conventional health and safety SA SA SA SA SA
Environmental protection SA SA SA SA SA
Emergency management and fire protection SA SA SA SA SA
Waste management SA SA SA SA SA
Security SA SA SA SA SA
Safeguards and non-proliferation SA SA SA SA SA
Packaging and transport SA SA SA SA SA
Table E-4: Safety and control area ratings, Key Lake Operation, 2013–17
Safety and control area 2013 2014 2015 2016 2017
Management system SA SA SA SA SA
Human performance management SA SA SA SA SA
Operating performance SA SA SA SA SA
Safety analysis SA SA SA SA SA
Physical design SA SA SA SA SA
Fitness for service SA SA SA SA SA
Radiation protection SA SA SA SA SA
Conventional health and safety SA SA SA SA SA
Environmental protection SA SA SA SA SA
Emergency management and fire protection SA SA SA SA SA
Waste management SA SA SA SA SA
Security SA SA SA SA SA
Safeguards and non-proliferation SA SA SA SA SA
Packaging and transport SA SA SA SA SA
Table E-5: Safety and control area ratings, McClean Lake Operation, 2013–17
Safety and control area 2013 2014 2015 2016 2017
Management system SA SA SA SA SA
Human performance management SA SA SA SA SA
Operating performance SA SA SA SA SA
Safety analysis SA SA SA SA SA
Physical design SA SA SA SA SA
Fitness for service SA SA SA SA SA
Radiation protection SA SA SA SA FS
Conventional health and safety SA SA SA SA SA
Environmental protection SA SA SA SA SA
Emergency management and fire protection SA SA SA SA SA
Waste management SA SA SA SA SA
Security SA SA SA SA SA
Safeguards and non-proliferation SA SA SA SA SA
Packaging and transport SA SA SA SA SA
Table E-6: Applicable SCA performance ratings for historic sites, 2015
Safety and control area Gunnar* Lorado Deloro
Management system N/A SA BE**
Operating performance N/A SA SA
Physical design N/A SA SA
Radiation protection SA SA SA
Conventional health and safety SA SA SA
Environmental protection SA SA SA
Emergency management and fire protection SA SA SA
Security SA SA SA

* The management systems, physical design, and emergency management and fire protection SCAs were not rated for 2015 because remediation work had not yet begun and there were no workers onsite.

** Addressed in CMD 16-M49.

Table E-7: Applicable SCA performance ratings for historic sites, 2016–17
Safety and control area Gunnar Lorado Madawaska* Deloro
Management system SA SA SA SA
Physical design SA SA SA SA
Radiation protection SA SA SA SA
Conventional health and safety SA SA SA SA
Environmental protection SA SA SA SA
Emergency management and fire protection SA SA SA SA
Security SA SA SA SA
* Maintenance and rehabilitation work began at the Madawaska site in 2016.
Table E-8: Applicable SCA performance ratings for decommissioned sites, 2015
Safety and control area Beaverlodge Cluff Lake Rayrock Port Radium Agnew Lake Madawaska Bicroft Dyno Elliot Lake Denison and Stanrock
Radiation protection SA SA SA SA SA SA SA SA SA SA
Conventional health and safety SA SA SA SA SA SA SA SA SA SA
Environmental protection SA SA SA SA SA SA SA SA SA SA
Table E-9: Applicable SCA performance ratings for decommissioned sites, 2016
Safety and control area Beaverlodge Cluff Lake Rayrock Port Radium Agnew Lake Bicroft Dyno Elliot Lake Denison and Stanrock
Radiation protection SA SA BE* BE* BE* SA SA SA SA
Conventional health and safety SA SA SA SA SA SA SA SA SA
Environmental protection SA SA SA SA SA SA SA SA SA
Table E-10: Applicable SCA performance ratings for decommissioned sites, 2017
Safety and control area Beaverlodge Cluff Lake Rayrock Port Radium Agnew Lake Bicroft Dyno Elliot Lake Denison and Stanrock
Radiation protection SA SA SA SA SA SA SA SA SA
Conventional health and safety SA SA SA SA SA SA SA SA SA
Environmental protection SA SA SA SA SA SA SA BE* SA

## Appendix F: Financial Guarantees

Table F-1 outlines the financial guarantee values, as of December 31, 2017, for the five operating uranium mine and mill facilities discussed in this report.

Table F-1: Operating uranium mines and mill facilities – Financial guarantees
Site Value in Canadian dollars
Cigar Lake Operation $49,200,000 McArthur River Operation$48,400,000
Rabbit Lake Operation $202,700,000 Key Lake Operation$218,300,000
McClean Lake Operation $107,241,000 Total$625,841,000

Table F-2 outlines the financial guarantees, as of December 31, 2017, for the historic and decommissioned sites discussed in this report.

Table F-2: Historic and decommissioned sites – Financial guarantees
Site Value in Canadian dollars
Gunnar Responsibility of provincial government
Lorado Responsibility of provincial government
Deloro Responsibility of provincial government
Madawaska $4,041,472 Beaverlodge Responsibility of provincial government Cluff Lake$33,600,000
Rayrock Responsibility of provincial government
Port Radium Responsibility of provincial government
Agnew Lake Responsibility of provincial government
Bicroft $1,837,000 Dyno$1,871,543
Elliot Lake $32,749,000 Denison and Stanrock$2,480,000

## Appendix G: Worker Dose Data

Table G-1 shows the number of nuclear energy workers (NEWs) monitored at each of the five operating uranium mine and mill sites for 2017. An individual who is required to work with a nuclear substance or in a nuclear industry is designated as a NEW if he or she has a reasonable probability of receiving an individual effective dose greater than the prescribed effective dose limit for a member of the public (i.e., 1mSv in a calendar year).

Cigar Lake McArthur River Rabbit Lake Key Lake McClean Lake 1,107 958 153 684 334

Table G-2 compares the average and maximum individual effective doses to NEWs at the five operating uranium mines and mills for 2017. No regulatory dose limits were exceeded at any of these facilities during 2017.

Table G-2: Radiation dose data for NEWs at uranium mines and mills, 2017
Facility Average individual effective dose (mSv/year) Maximum individual effective dose (mSv/year) Regulatory limit
Cigar Lake Operation 0.34 3.36 50 mSv/year
McArthur River Operation 0.79 5.73
Rabbit Lake Operation 0.40 1.56
Key Lake Operation 0.66 5.39
McClean Lake Operation 0.91 5.12

Tables G-3 to G-7 show five-year trends (from 2013 to 2017) of the average and maximum effective annual doses to NEWs at the five active mining and milling operations. Each of these tables also identifies the maximum five-year dose to an individual NEW at each operating uranium mine and mill. No radiation dose at any operating facility exceeded a regulatory effective dose limit during 2017, or for the five-year dosimetry period from 2013 to 2017 .

Table G-3: Radiation dose data for NEWs, Cigar Lake Operation, 2013–17
Dose data 2013 2014 2015 2016 2017 Regulatory limit
Number of NEWs 3,039 1,458 1,222 1,243 1,107 N/A
Average individual effective dose (mSv) 0.27 0.16 0.45 0.39 0.34 50 mSv/year
Maximum individual effective dose (mSv) 2.21 2.04 5.99 5.53 3.36 50 mSv/year
Maximum five-year dose to an individual NEW (mSv), 2016–20 8.59 100 mSv/5-year dosimetry period
Table G-4: Radiation dose data for NEWs, McArthur River Operation, 2013–17
Dose data 2013 2014 2015 2016 2017 Regulatory limit
Total NEWs 1,302 1,149 1,360 1,064 958 N/A
Average individual effective dose (mSv) 0.89 1.03 1.00 0.85 0.79 50 mSv/year
Maximum individual effective dose (mSv) 7.58 7.91 7.40 7.02 5.73 50 mSv/year
Maximum five-year dose to an individual NEW (mSv) 2016–20 9.73 100 mSv/5 year dosimetry period
Table G-5: Radiation dose data for NEWs, Rabbit Lake Operation, 2013–17
Dose data 2013* 2014 2015 2016 2017 Regulatory limit
Total NEWs 1,178 964 958 739 153 N/A
Average individual effective dose (mSv) 1.30 1.32 1.36 0.85 0.4 50 mSv/year
Maximum individual effective dose (mSv) 11.67 8.84** 9.14 4.95 1.56 50 mSv/year
Maximum five-year dose to an individual NEW (mSv) 2016–20 6.30 100 mSv/5 year dosimetry period

* In 2013, the 2012 maximum individual effective dose was modified from 14.37 mSv (as stated in the previous CNSC Staff Report on the Performance of Canadian Uranium Fuel Cycle and Processing Facilities: 2012), as a result of approved dose changes following an injury to an underground worker (for further information see section 5.2 of the 2013 report).

** During a dosimetry database upgrade, some errors associated with timecard and database entries, which affected some dose assignments at Rabbit Lake, Cigar Lake and McArthur River, were identified. The errors were not significant and did not result in any changes to the data reported in the 2016 CNSC regulatory oversight report, with the exception of the 8.84 mSv value, which had been previously reported as 8.64 mSv.

Table G-6: Radiation dose data for NEWs, Key Lake Operation, 2013–17
Dose data 2013 2014 2015 2016 2017 Regulatory limit
Total NEWs 1,380 1,170 1,191 837 684 N/A
Average individual effective dose (mSv) 0.62 0.63 0.55 0.62 0.66 50 mSv/year
Maximum individual effective dose (mSv) 5.67 6.21 7.56 5.37 5.39 50 mSv/year
Maximum five-year dose to an individual NEW (mSv) 2016–20 9.6 100 mSv/5 year dosimetry period
Table G-7: Radiation dose data for NEWs, McClean Lake Operation, 2013–17
Dose data 2013 2014 2015 2016 2017 Regulatory limit
Total NEWs 308 894 508 510 334 N/A
Average individual effective dose (mSv) 0.36 0.37 0.89 1.04 0.91 50 mSv/year
Maximum individual effective dose (mSv) 3.44 2.03 5.28 6.94 5.12 50 mSv/year
Maximum five-year dose to an individual NEW (mSv) 2016–20 11.05 100 mSv/5 year dosimetry period

Tables G-8 and G-9 present the maximum and average individual effective doses, for historic and decommissioned sites where there were workers designated as NEWs in 2016 and 2017. The Cluff Lake, Beaverlodge, Lorado, Rayrock, Port Radium, Agnew Lake, Bicroft and Dyno sites did not have NEWs onsite during 2016 and 2017.

Table G-8: Radiation dose data for NEWs, historic and decommissioned sites, 2016
Facility Maximum individual effective dose in 2016 (mSv/yr) Average individual effective dose in 2016 (mSv/yr) Regulatory limit
Gunnar 0.6 0.12 50 mSv/yr
Deloro 0.35 <0.1
Madawaska 0.61 <0.07
Denison and Stanrock 1.02 0.49
Elliot Lake 1.02 0.49
Table G-9: Radiation dose data for NEWs, historic and decommissioned sites, 2017
Facility Maximum individual effective dose in 2017 (mSv/yr) Average individual effective dose in 2017 (mSv/yr) Regulatory limit
Gunnar 1.37 0.12 50 mSv/yr
Deloro N/A* N/A*
Madawaska 0.61 <0.07
Denison and Stanrock 0.59 0.40
Elliot Lake 0.59 0.40
* In 2017, as the work on the cover was completed, the dosimetry program that was in place during the remediation was discontinued due to low dose rates.

## Appendix H: Reportable Releases to the Environment (Spills) and Definitions of CNSC Significance Ratings

Table H-1 presents information on reportable releases to the environment (spills) during 2017. Canadian Nuclear Safety Commission (CNSC) staff were satisfied with the remedial actions taken by licensees, and concluded that these spills resulted in no residual impacts to the environment.

Table H-1: Uranium mines and mills reportable releases to the environment, 2017
Facility Details Corrective actions Significance rating
Cigar Lake Operation On February 22, 2017, anhydrous ammonia was released from a modular freeze plant stem valve installed on the sub-cooler equalizer line, resulting in a release of approximately 4 kg of ammonia released to the atmosphere. The cause of the release was the failure of a stem valve on the sub-cooler portion of the system. This failure was caused by low-frequency vibration in the system.

To prevent a recurrence, the stem valve was repaired, tested and placed back into service. Possible further dampening of the system to reduce vibration was evaluated.

CNSC staff were satisfied with the corrective actions implemented.

Low
Cigar Lake Operation On July 3, 2017, the seal on the suction valve on compressor no. 4 of modular freeze plant no. 2 had a small leak, allowing approximately 1 kg of anhydrous ammonia to be released to the atmosphere.

To prevent future similar occurrences, assessment will be completed on valve seating, to inspect valves for proper seating tolerances and to provide recommendations whether valves need to be replaced.

CNSC staff were satisfied with the corrective actions implemented.

Low
Cigar Lake Operation On July 26, 2017, during operation of modular freeze plant no. 1, the standby oil filter housing fractured resulting in a release of approximately 4 kg of ammonia gas.

To prevent similar occurrences, bypass filters on all other modular freeze plants were checked for pressure build up or external visual concerns. Several long-term corrective actions were being assessed for implementation. These included:

• third-party examination of oil filter housings from modular freeze plant no.1 to determine failure mode and other non-destructive testing
• change of the maintenance plan for the oil filter housings (if required), based on the results of the above testing
• removal and visual inspection of remaining oil filter housings
• clear documentation of work process for filter replacement
• review of failure mode and effects analysis of the compressor system, to determine if there are other areas that may require regular inspection

CNSC staff are satisfied with the corrective actions implemented.

Low
Cigar Lake Operation On August 6, 2017, the intercooler line on modular freeze plant no. 2 leaked, releasing small amounts of ethylene glycol and hydraulic oil. Further investigation into the event identified that the system lost approximately 317 kg of ammonia. This event was the result of a failure, likely caused by corrosion, of a tube or tubes in the freeze plant’s shell and tube heat exchanger.

To prevent future occurrences, several corrective actions have been implemented or were being assessed for implementation. These include:

• periodic testing of fluids from the heat exchangers to see if the fluids had intermixed, as that would have been a potential indicator of future heat exchanger problems
• assessment of the corrosion inhibitor in the glycol system to determine if changes could be made to improve performance.
• change of the inspection protocol of the system to improve monitoring of ammonia receiver site glass levels

CNSC staff were satisfied with the corrective actions implemented.

Low
Cigar Lake Operation On December 6, 2017, a temporary power loss to the primary freeze plant caused an isolation valve on a line to leak approximately 13 kg of ammonia.

To prevent similar occurrences, it was planned to examine the valve in question to determine the failure mode and actions put in place to mitigate future releases of this type.

CNSC staff were satisfied with the corrective actions implemented.

Low
McArthur River Operation On December 2, 2017, personnel entering the south freeze plant reported the smell of ammonia. Upon investigation, refrigeration mechanics identified two small leaks, on a 90-fitting socket weld, on the inlet of the relief three-way value on skid no. 2 and a small leak from a threaded union on skid no. 1, resulting in the release of trace amounts of ammonia.

To prevent a reoccurrence. skid no. 2 was taken out of service, a repair plan was developed with the refrigeration contractor and the leak was repaired. The small leak on skid no. 1 was repaired immediately after discovery. While the exact amount of ammonia released could not be determined, none of the ammonia detectors in the plant displayed elevated concentrations of ammonia during this event, indicating the plant remained at safe levels well below the 8-hour average regulatory limit of 25 ppm.

CNSC staff were satisfied with the corrective actions implemented.

Low
McArthur River Operation On December 31, 2017, a refrigeration mechanic entered the main freeze plant and noticed the smell of ammonia. The mechanic identified that a trace amount of ammonia had been released from a worn shaft seal coupling.

To prevent similar occurrences the compressor was shut down and shaft seal was replaced. The exact amount of ammonia released is unknown; none of the ammonia detectors in the plant displayed elevated concentrations of ammonia during this event, indicating that the plant remained at safe levels well below the 8-hour average regulatory limit of 25 ppm.

CNSC staff were satisfied with the corrective actions implemented.

Low
Rabbit Lake Operation On December 3, 2017, a Rabbit Lake mill line patrol operator called the mill control room operator to report the smell of propane near the environment and health lab. Investigation following the event determined that a mechanical seal on the supply side of one of the propane pumps that serves camp had failed. Due to the failed mechanical seal, propane gas was released from a weep hole at the bottom of the pump. The mechanical seals are designed to release propane from the weep hole in case of failure. Based on the relatively short time frame, the pump was known to be leaking at operational pressure and flows (~10 minutes), it was estimated that approximately 17 L of liquid propane was released.

To prevent recurrence, the faulty pump was replaced with a new pump and leak tested before being made available for service. Cameco intended to assess if the propane pumps for the Camp Propane Farm could be bypassed; they were not currently required for use during care and maintenance. A two-year preventative maintenance program to replace mechanical seals in all propane pumps used at the Rabbit Lake Operation was also planned to be instituted, to reduce the likelihood of future mechanical seal failures. In addition, it was identified, that to aid in detection of a propane release from the camp propane farm, that a lower explosive limit alarm to a beacon should be installed.

CNSC staff were satisfied with the corrective actions implemented.

Low
Key Lake Operation

On April 15, 2017, approximately 130 kg of low-grade ore used to feed the crushing and grinding plant as blend material was released to a site road at one location adjacent to the ore pad, as well as to ground at the mine shop parking rail from a front-end loader bucket.

All material, including the remaining material in the loader bucket involved with the event was transported back to the ore stockpile to be used as blend material in the mill process. Following cleanup of the affected areas, a gamma scan was performed and gamma levels were consistent with background gamma radiation levels for the two areas affected.

To prevent a recurrence the Key Lake Operation initiated preventative actions under the employee relations personal accountability and corrective action process.

CNSC staff inspected the area as part of a compliance inspection and were satisfied with the corrective actions implemented.

Low
Key Lake Operation

On June 24, 2017, an intermittent leak was discovered coming from piping on no. 2 ammonia storage tank by the solvent extraction facility. Upon inspection of the tank, the leak was determined to be on the liquid draw line at the bottom of the tank that leads to the vaporizer. No release volume could be estimated, since the leak was intermittent.

The tank was drained and repairs to the piping were completed.

To prevent a recurrence of this and similar events, the Key Lake Operation initiated a three-year staged ammonia tank refurbishment project for all three ammonia tanks at the mill. The refurbishment program was planned for 2018–20, with one ammonia tank and associated infrastructure being refurbished per year.

CNSC staff were satisfied with the corrective actions implemented.

Low
Key Lake Operation On December 8, 2017, an intermittent leak was discovered on a vapour line from no. 3 ammonia storage tank by the solvent extraction facility. Upon inspection of the line the leak was determined to be at a flange. No release volume could be estimated because the link was intermittent.

To prevent a recurrence of this and similar events the Key Lake Operation initiated a three-year staged ammonia tank refurbishment project for all three ammonia tanks at the mill. The refurbishment program was planned for 2018–20, with one ammonia tank and associated infrastructure being refurbished per year.

CNSC staff were satisfied with the corrective actions implemented.

Low
McClean Lake Operation On January 12, 2017, AREVA personnel noticed that approximately 2 L of anhydrous ammonia had leaked onto the ground at the anhydrous ammonia offloading station during previous night shift. Temperatures overnight dipped to -41.3oC and averaged -36.1oC. The consistent low temperatures kept the anhydrous ammonia in liquid form. Under warmer conditions, such a small amount would have dissipated as a gas. AREVA personnel followed up with Northern Resource Trucking (NRT) and it was confirmed with the truck operator that there had been a small leak on a valve housing on the anhydrous ammonia trailer during the offload. The affected ground was scraped up and the material taken to the hydrocarbon land farm for disposal.

The release was a result of a leak caused by loose bolts on the anhydrous ammonia offload line valve on the delivery trailer. The container itself was not a factor in the spill and was found to be in good condition. The trailer that leaked was a temporary rental trailer and did not belong to NRT, whose regular trailer had been out of service for repairs. To prevent a recurrence, NRT confirmed with the rental company that all valves would be checked prior to any future rentals.

CNSC staff were satisfied with the corrective actions implemented.

Low
McClean Lake Operation An incident occurred on June 26, 2017, during pond cleaning operations at the SABRE project site while suctioning pond slurry into the hydrovac truck. Upon filling of the tank, rather than hitting the button on the remote to stop the vacuum pump, the operator inadvertently pressed the button that activated the rear gate. The discharge door lock-out valve failed, and the gate opened and discharged the load to the ground next to the ponds. Most of the material immediately ran back to the pond, with approximately 1,000 L falling on the ground. Cleanup started immediately with the hydrovac and was completed the next day. All material was scraped up. A post cleanup soil sample was collected and a control sample was collected from soil nearby on the berm of the pond. Results for both the control and post‑cleanup samples are largely consistent. A post‑cleanup gamma survey was also conducted and demonstrated that all values were within 0.5 µSv per hour of background values.

To prevent a reoccurrence, the discharge door lock-out valve was replaced with a more robust valve with a locking cover and a lock pin to ensure that the valve would remain closed. Also, during replacement of the lock-out valve that was done immediately post-incident, it was noticed that there was air in the discharge door lock-out hydraulic system, which could also have caused the mechanism to fail. The discharge door lock-out hydraulic system was therefore also bled, to remove any air in the system.

CNSC staff were satisfied with the corrective actions implemented.

Low
McClean Lake Operation

On August 29, 2017, during start-up of the sulphuric acid plant after the summer shutdown, acid leaked from the drying tower into the blower, and through the blower out onto the floor in the acid plant. After the acid was cleaned out of the area, the floor was inspected. It was determined that there was a gap around the sump that penetrated below the concrete slab of the floor. It is normal practice to leave a gap between slab edge and a sump wall; however, the gap had normally been filled with a flexible expansion joint material. In this case, the material had deteriorated. It was estimated that approximately 50 kg of sulphuric acid could have been discharged through the gap. The cause of the discharge of acid to the sump and floor in that area was that the drying tower return line was plugged.

To prevent a recurrence, the gap was repaired with Silkaflex sealant, which is a polyurethane‑based sealant that cures with moisture and is not affected by chemicals or solvents. Various operation, maintenance and inspection processes were implemented and/or revised in order to prevent future blockages of the acid return line.

CNSC staff were satisfied with the corrective actions implemented.

Low

Table H-2 presents definitions that CNSC staff use to rate the significance of a spill.

Table H-2: CNSC spill rating definitions
Safety significance Radiation protection Environmental protection
Definition Directorate-specific examples Definition Directorate-specific examples
High

Exposures to multiple workers in excess of regulatory limits.

Widespread contamination to several persons or to a place.

Incident that results in, or has reasonable potential for, a worker to exceed regulatory limits.

Examples:

• Nuclear energy worker (NEW) exceeding 20 millisievert (mSv)/year or 100 mSv/five years
• Non-NEW exceeding 1 mSv
Nuclear or hazardous substances being released to the environment exceeding regulatory limits (including public exposure) or that results in significant impact to the environment.

Incident that results in, or has reasonable potential to have, a significant or moderate impact or extensive future remediation.

Examples:

• impairment of ecosystem functions
• effluent licence limit exceedance
• spill into fish bearing water
• fish kill
Medium

Exposure to a worker in excess of regulatory limits.

An incident that would result in a licensee exceeding action level.

Limited contamination that could affect a few persons or a limited area.

Incident that results in or has reasonable potential to exceed an action level.

Example:

• Doses to workers of 1 mSv/week or 5 mSv/quarter
Nuclear or hazardous substances being released to the environment exceeding action levels (including public exposure) or that result in impact to the environment outside the licensing basis.

Incident that results in, or has reasonable potential to have, a minor impact or that requires some future remediation.

Examples:

• effluent action level exceedance
• spills to environment (including atmosphere) with short-term or seasonal impacts
Low

Increased dose below reportable limits.

Contamination that could affect a worker.

Incident that results in, or has reasonable potential to exceed, the highest administrative level. Release of hazardous or nuclear substances to the environment below regulatory limits.

Incident that results in, or has reasonable potential to have, a negligible impact.

Examples:

• effluent administrative level-exceedance
• spills to environment (including atmosphere) with no future impacts

## Appendix I: Lost-Time Injuries

A lost-time injury (LTI) is a workplace injury that results in the worker being unable to return to work for a period of time. Table I-1 outlines the LTIs reported in the 2017 reporting period at the five operating uranium mines and mills.

Table I-1: Uranium mines and mills – Lost-time injuries, 2017
Facility Incident Corrective action Significance rating
Cigar Lake Operation No LTIs were reported.
McArthur River Operation The original injury had occurred in April 2016, when a worker felt hip pain while stepping off mining equipment. The worker received first aid medical treatment before being placed on restricted work status. In October 2017, the worker was seen by a doctor and deemed unable to fly to the site, resulting in lost time. Cameco was conducting an analysis on the potential causal factors of the injury and will provide CNSC staff with any corrective actions to be implemented, if applicable. Medium
Rabbit Lake Operation No LTIs were reported.
Key Lake Operation No LTIs were reported.
McClean Lake Operation No LTIs were reported.

## Appendix J: Exceedances of Radiological Action Levels Reported to the CNSC

As per Table J-1, there were no exceedances of radiological action levels in 2017 at any of the five operating uranium mines and mills.

Table J-1: Uranium mines and mills – Exceedances of radiological action levels in 2017
Facility Action level exceedance Corrective action
Cigar Lake Operation None reported N/A
McArthur River Operation None reported N/A
Rabbit Lake Operation None reported N/A
Key Lake Operation None reported N/A
McClean Lake Operation None reported N/A

## Appendix K: Annual Releases of Radionuclides to the Environment

Operating uranium mines and mills in northern Saskatchewan, and the waste management operations in the Elliot Lake region, have process waters that require capture, treatment and release through a final point of control. This appendix represents the total annual releases of relevant radionuclides from these facilities from 2013 through 2017.

This appendix includes details on releases of radionuclides of interest belonging to the natural uranium decay series:

• Total uranium: Total uranium as a metal is the contaminant of interest, rather than specific uranium isotopes, as uranium is more chemically toxic than radiologically toxic. Releases for total uranium are reported in kilograms (kg)
• Progeny of uranium‑238 (thorium-230, radium-226, lead-210 and polonium-210): The primary uranium-238 progeny of interest are alpha emitters with half-lives long enough (> 10 days) for them to participate in environmental and biological uptake processes of relevance to low-dose chronic exposures. These progeny include thorium-230, radium-226, lead-210 and polonium‑210. Uranium-234, with a half-life of 24,600 years, is accounted for within the total uranium category. Releases of uranium U‑238 progeny are reported in becquerels (Bq).

Liquid releases to surface waters

At the uranium mines and mills in northern Saskatchewan, process waters are monitored for total uranium and a number of uranium-238 progeny. The Elliot Lake region’s waste management facilities are less dynamic operations, and monitoring of process waters is focused on total uranium and radium-226. The total annual load of relevant radionuclides from the facilities in Northern Saskatchewan and Elliot Lake is provided in tables K-1 and K‑2, respectively.

Table K-1:  Total annual load of uranium and relevant uranium-238 progeny released in liquid effluent to surface waters from uranium mines and/or mills in northern Saskatchewan, from 2013–17
Facility and year Uranium (kg) Thorium-230 (MBq) Radium-226 (MBq) Lead-210 (MBq) Polonium-210 (MBq)
Cigar Lake Operation
2013 0.23 1.76 2.92 14.10 3.56
2014 6.63 2.00 2.74 8.47 7.57
2015 38.00 3.73 3.13 8.00 10.70
2016 2.36 3.81 2.71 8.69 6.41
2017 0.72 3.27 3.05 9.27 4.86
McArthur River Operation
2013 24.4 22.7 117.7 45.5 106.8
2014 22.8 22.7 87.4 51.0 92.7
2015 21.2 23.6 152.9 55.9 184.4
2016 12.7 26.7 151.6 51.6 100.5
2017 12.9 24.5 161.5 49.0 96.4
Rabbit Lake Operation
2013 266.8 85 32.7 <DL 138.2
2014 199.7 96.7 41.0 96.7 96.7
2015 220.7 84.9 30.0 339.5 106.1
2016 326.9 89.9 32.9 359.6 89.9
2017 274.0 117.0 25.6 311.9 78.0
Key Lake Operation
2013 9.5 88.3 56.6 97.5 31.5
2014 6.0 48.2 53.0 90.7 82.2
2015 7.5 65.8 64.4 75.2 16.4
2016 4.8 77.0 41.7 53.9 15.4
2017 7.3 69.2 61.8 23.8 7.7
McClean Lake Operation – Combined releases from the JEB and Sue water treatment plants
2013 1.8 19.6 6.0 74.4 17.7
2014 2.3 12.1 7.2 48.6 13.3
2015 5.5 16.4 10.8 54.5 26.3
2016 6.5 20.2 12.0 122.1 61.3
2017 5.7 18.8 11.7 88.5 30.8
Table K-2: Total annual load of uranium and radium-226 for the tailings waste management facilities in the Elliot Lake region for the years 2013–17
Facility and Year Uranium (kg) Radium-226 (MBq)
Pronto effluent treatment plant final discharge
2013 16.3 238.4
2014 13.3 205.8
2015 8.8 155.4
2016 10.3 145.9
2017 15.4 217.1
Nordic effluent treatment plant final discharge
2013 14.6 245.0
2014 25.1 250.9
2015 9.3 146.2
2016 7.2 122.8
2017 10.8 152.7
Panel effluent treatment plant final discharge
2013 13.2 238.7
2014 11.7 283.6
2015 7.3 105.7
2016 9.9 237.0
2017 16.0 365.5
Quirke effluent treatment plant final discharge
2013 56.5 364.2
2014 41.4 215.7
2015 38.9 157.9
2016 35.4 205.4
2017 42.9 417.3
Elliot Lake – Stanleigh treatment plant discharge
2013 23.8 2403.5
2014 19.1 2087.2
2015 13.8 976.7
2016 15.7 2143.1
2017 14.8 2375.1
Denison tailings management area-1 effluent treatment plant final discharge
2013 109.6 266.7
2014 79.0 376.9
2015 44.2 120.1
2016 52.5 202.7
2017 75.0 236.6
Denison lower Williams effluent treatment plant final discharge
2013 3.3 56.7
2014 1.5 47.3
2015 1.4 41.5
2016 0.9 28.7
2017 2.4 60.5
Stanrock effluent treatment plant final discharge
2013 4.0 77.5
2014 2.7 89.7
2015 2.8 83.5
2016 3.7 62.2
2017 8.1 138.5

## Appendix L: Website links

The following links provide additional information on some of the licensees, programs and subjects discussed in this report.

## Appendix M: Acronyms

ALARA
as low as reasonably achievable
CCME
Canadian Council of Ministers of the Environment
CMD
Commission member document
CNSC
Canadian Nuclear Safety Commission
COPC
constituents of potential concern
EARMP
Eastern Athabasca Regional Monitoring Program
EPR
environmental performance report
EQC
Environmental Quality Committee
ERA
environmental risk assessment
EWL
EWL Management Ltd.
HHERA
human health and ecological risk assessment
HHRA
human health risk assessment
IAEA
International Atomic Energy Agency
IC
institutional control
ICRP
International Commission on Radiological Protection
IEMP
Independent Environmental Monitoring Program
INAC
Indigenous and Northern Affairs Canada
JEB
John Everett Bates
LCH
licence conditions handbook
LLRD
long-lived radioactive dust
LTI
lost-time injury
MMER
Metal Mining Effluent Regulations
MNDM
Ministry of Northern Development and Mines
MOECC
Ontario Ministry of Environment and Climate Change
NEW
nuclear energy worker
NPRI
National Pollutant Release Inventory
NRT
Northern Resource Trucking
NSCA
Nuclear Safety and Control Act
PAD
personal alpha dosimeter
PFP
Participant Funding Program
PPE
personal protective equipment
ppm
parts per million
QSM
quantitative site model
RnG
radon gas
RnP
radon progeny
SABRE
surface access borehole resource extraction
SCA
safety and control area
SRC
Saskatchewan Research Council
TMF
tailings management facility
TMA
tailings management area
TSP
total suspended particulate
TSS
total suspended solids

## References

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