Environmental protection review report summary: Key Lake Operation
Environmental protection review (EPR) reports provide CNSC staff’s evaluation of how effectively licensees are protecting human health and the environment in the communities in which they operate. The following summary highlights key areas of interest from the EPR report for the Key Lake Operation. It represents only some of the information presented in the full report.
On this page:
- About the facility
- About the report
- Environmental monitoring
- Human health
- Related link – Full EPR report
About the facility
The Key Lake Operation is located within historic Treaty 10 territory, in the Homeland of the Métis, and is within the traditional territories of the Denesųłiné, Cree, and Métis peoples. The facility is located within the Athabasca Basin of northern Saskatchewan, approximately 570 km north of Saskatoon. Owned and operated by Cameco Corporation (Cameco), the Key Lake Operation consists of milling and tailings operations, water treatment facilities and monitoring ponds, contaminated water reservoir ponds, a domestic landfill, waste rock piles, special waste rock stockpiles, and mineralized waste/ore pads.
Under its current uranium mill operating licence, Cameco is authorized to produce uranium oxide at the Key Lake Operation. In November 2017, Cameco announced that the Key Lake Operation would transition to a state of care and maintenance by end of January 2018. Operations such as the wastewater treatment plants continued to operate. On February 9, 2022, Cameco announced its intent to begin the process of transitioning the Key Lake Operation from care and maintenance to production.
About the report
The following summary highlights key areas of interest from the EPR report for the Key Lake Operation. It represents only some of the information presented in the full report.
The purpose of the report is to share CNSC staff’s findings from their review of Cameco’s environmental protection measures. This includes staff’s assessment of any possible environmental releases as part of normal operations, and of the risks that radiological or hazardous (non-radiological) substances pose to the environment and human health. The report draws on information provided by Cameco and the CNSC’s technical assessments, and it includes information on:
- the results of Cameco’s environmental monitoring, as reported in annual reports
- Cameco’s 2013 human health and ecological risk assessment for the Key Lake Operation
- Cameco’s 2020 environmental risk assessment for the Key Lake Operation
- Cameco’s 2019 preliminary decommissioning plan for the Key Lake Operation
- plans for the CNSC’s Independent Environmental Monitoring Program (IEMP)
- results from other environmental monitoring programs and/or health studies (such as those completed by other levels of government) in proximity to Cameco’s Key Lake Operation
Overall, CNSC staff found that Cameco continues to implement and maintain effective environmental protection measures to adequately protect the environment and the health of people living in and around northern Saskatchewan. CNSC staff found that the potential risks to the environment from any of the releases from the Key Lake Operation observed between 2013 and 2021 are similar to the risks posed by natural background levels. It was also found that any health risk is similar to that experienced by similar northern communities.
Environmental monitoring
In the nuclear industry, any kind of contaminant emitted by a facility is called a release. This report looks at different kinds of releases and their possible impacts on the land, air and water in the area surrounding the Key Lake Operation, as well as any potential impact on human health.
Figure 1 illustrates how a release may reach the environment through what is called an exposure pathway. In the case of the Key Lake Operation, this graphic is a simplified representation of the facility and different types of releases—such as emissions in the air or effluent in the water—and the human and ecological receptors that may interact with the releases.
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The potential pathways represented in the graphic may include the following components: atmospheric release, groundwater discharge to surface water, wind erosion, airborne exposure, uptake by wildlife, uptake by sediment dwelling organisms, uptake by forage fish, uptake by predator fish and groundshine.
Cameco must monitor its releases and measure them against pre-established limits. It then reports its results to the CNSC and other levels of government. The CNSC verifies this data by conducting reviews and inspections of Cameco’s environmental protection programs.
CNSC monitoring
Under the IEMP, CNSC staff take samples – for example, of air, water, soil, sediment, vegetation, or local food like meat or vegetables – from public areas near nuclear facilities. For the uranium mines and mills in northern Saskatchewan, the IEMP sampling is conducted by a qualified contractor. The samples are then tested by a third-party laboratory for contaminants related to each facility's operations, including radionuclides and hazardous substances.
In summer 2021, a qualified contractor conducted IEMP sampling around the Key Lake Operation. As part of that sampling campaign, input from relevant Indigenous Nations and communities informed the selection of samples, which included water, Labrador tea, blueberries, fish and moose. Visit the CNSC’s IEMP web page for more information, including detailed sampling results.
Cameco’s monitoring
Atmospheric releases
Cameco controls and monitors airborne emissions from the Key Lake Operation to the environment. Cameco monitors for both radiological and hazardous emissions. At the facility are various potential sources of airborne releases including material handling of ore and waste rock, wind erosion of ore and waste rock, grading of unpaved roads, ventilation exhaust from the milling infrastructure, and fugitive sources of radon. Mitigation systems are in place to reduce the amount of airborne emissions released to the environment, including the use of srubbers before discharge.
Since January 2018, Key Lake Operation has been in care and maintenance. Therefore, the sulphuric acid plant has been shut down and there have been no releases of sulphur dioxide to the environment.
The monitoring results (see table 1) show that air emissions from the Key Lake Operation are very low. As a result, CNSC staff have found that Cameco continues to provide adeuqate protection of people and the environment.
| Parameter (tonnes) | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 |
|---|---|---|---|---|---|---|---|---|
| Sulphur Dioxide | 224.1 | 208.1 | 85.3 | 325.1 | 159.9 | - | - | - |
| Oxides of Nitrogen (NO2) | 106.0 | 137.1 | 148.0 | 70.7 | 35.0 | 39.0 | 20.6 | 24.2 |
| Ammonia (total) | 43.0 | 39.6 | 34.0 | 32.1 | 30.2 | 7.5 | - | - |
| Volatile Organic Compounds | 171.1 | 132.1 | 163.7 | 115.0 | 111.1 | - | - | - |
| Carbon Monoxide | 348.0 | 347.9 | 344.9 | 358.0 | 109.6 | - | - | - |
| Particulate matter | 63.5 | 71.2 | 157.6 | 102.7 | 101.4 | 46.1 | 55.0 | 34.4 |
| particulate matter less than 10 microns in diameter | 17.9 | 16.9 | 45.2 | 32.6 | 30.2 | 16.7 | 18.5 | 12.8 |
| particulate matter less than 2.5 microns in diameter | 4.8 | 4.6 | 7.7 | 6.0 | 5.2 | 3.7 | 3.9 | 2.4 |
Liquid releases
Cameco routinely monitors and controls liquid effluent released from the Key Lake Operation to the environment. The Key Lake Operation has 2 water treatment plants:
- the bulk neutralization circuit (within the mill), which receives contaminated water feeds, removes dissolved metals and suspended solids, and discharges treated water into Wolf Lake
- the reverse osmosis treatment plant, which receives groundwater from recovery wells around the Gaertner pit, and removes ions and dissolved substances before release to Horsefly Lake
The monitoring results from the bulk neutralization circuit (see table 2) show that water releases (treated liquid effluent) were at levels below release limits during the monitoring period, with the exception of 1 event in 2022.
In November 2022, an action level exceedance of total suspended solids (TSS) occurred at the bulk neutralization circuit. A surface water sample collected by Cameco at Wolf Lake demonstrated a TSS concentration within historical ranges. As of December 1, 2022, Cameco’s investigation remained underway.
| Parameter | Licence limit | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 |
|---|---|---|---|---|---|---|---|---|---|---|
| Arsenic (mg/L) | 0.3 | 0.008 | 0.008 | 0.006 | 0.007 | 0.008 | 0.0076 | 0.0075 | 0.0113 | 0.0109 |
| Copper (mg/L) | 0.3 | 0.013 | 0.014 | 0.030 | 0.029 | 0.023 | 0.005 | 0.001 | 0.001 | 0.002 |
| Lead (mg/L) | 0.1 | <0.01 | <0.01 | 0.01 | 0.01 | 0.01 | 0.01 | 0.0003 | 0.0002 | 0.0004 |
| Nickel (mg/L) | 0.5 | 0.067 | 0.049 | 0.071 | 0.144 | 0.167 | 0.257 | 0.142 | 0.153 | 0.094 |
| Zinc (mg/L) | 0.5 | 0.009 | 0.012 | 0.009 | 0.010 | 0.009 | 0.009 | 0.007 | 0.006 | 0.005 |
| pH (a) | 6.0 to 9.5 | 6.3 | 6.3 | 6.4 | 6.4 | 6.5 | 6.7 | 6.6 | 6.6 | 7.0 |
| Radium-226 (Bq/L) | 0.37 | 0.05 | 0.05 | 0.07 | 0.05 | 0.07 | 0.07 | 0.09 | 0.036 | 0.017 |
| Total suspended solids (mg/L) | 15 | 1.8 | 1.8 | 2.8 | 2.1 | 3.1 | 2.0 | 2.0 | 2.3 | 1.7 |
| Un-ionized Ammonia (mg/L) | 0.5(b)(c) | 0.012 | 0.019 | 0.016 | 0.015 | 0.015 | 0.004 | 0.003 | 0.003 | 0.02 |
| Selenium (mg/L) | 0.6 (d) | 0.017 | 0.018 | 0.018 | 0.017 | 0.015 | 0.010 | 0.010 | 0.011 | 0.010 |
| Uranium (mg/L) | 2.5 (e) | 0.008 | 0.006 | 0.008 | 0.006 | 0.011 | 0.013 | 0.0243 | 0.0259 | 0.0239 |
| Molybdenum (mg/L) | N/A (f) | 0.15 | 0.16 | 0.10 | 0.08 | 0.12 | 0.07 | 0.05 | 0.056 | 0.038 |
- (a) The pH is taken from every discharge sample. It is not measured in monthly composite samples.
- (b) The un-ionized ammonia data from 2013 to 2020 were calculated using the pH, temperature, and ammonia concentrations.
- (c) Un-ionized ammonia was added to the Metal and Diamond Mining Effluent Regulations (MDMER) in 2021.
- (d) This is the provincial limit that is not in the CNSC licence.
- (e) This is the provincial limit that is not in the CNSC licence. As discussed in subsection 3.1.1 of the full report, in the absence of a CNSC licence limit for uranium, the CNSC uses the interim objective for uranium of 0.1 mg/L as a benchmark to demonstrate the application of the ALARA and BATEA principles.
- (f) Refer to subsection 3.1.1 of the full report for an explanation of why no provincial or federal licence limits currently exist for molybdenum.
The monitoring results from the reverse osmosis water treatment plant (see table 3) show that water releases (treated liquid effluent) from the bulk neutralization circuit were at levels below release limits during the monitoring period, with the exception of an event in December 2013 and October 2018. Cameco completed investigations and developed corrective actions that the CNSC reviewed and found acceptable.
From 2013 to 2021, CNSC staff have found that Cameco’s treatment of liquid effluent is providing appropriate protection to people and the environment.
| Parameter (a) | Licence limit | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 |
|---|---|---|---|---|---|---|---|---|---|---|
| Arsenic (mg/L) | 0.3 | 0.0001 | 0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
| Copper (mg/L) | 0.3 | <0.0002 | 0.0002 | <0.0002 | <0.0002 | 0.0002 | 0.0002 | <0.0002 | <0.0002 | <0.0002 |
| Lead (mg/L) | 0.1 | <0.0001 | 0.0001 | 0.0001 | 0.0001 | <0.0001 | 0.0001 | <0.0001 | <0.0001 | <0.0001 |
| Nickel (mg/L) | 0.5 | 0.0287 | 0.0245 | 0.0217 | 0.0323 | 0.0112 | 0.0160 | 0.0310 | 0.0414 | 0.0487 |
| Zinc (mg/L) | 0.5 | 0.0022 | 0.0014 | 0.0007 | 0.0012 | 0.0006 | 0.0011 | 0.0025 | 0.0026 | 0.0037 |
| pH | 6.0 to 9.5 | 6.8 | 6.4 | 6.4 | 6.6 | 6.5 | 6.6 | 6.8 | 6.8 | 6.8 |
| Radium-226 (Bq/L) | 0.37 | 0.007 | 0.006 | 0.005 | 0.006 | 0.006 | 0.005 | 0.006 | 0.005 | 0.005 |
| Total suspended solids (mg/L) | 15 | 0.3 | 0.2 | 0.2 | 0.2 | <0.2 | 0.2 | 0.2 | 1.1 | 1.1 |
| Un-ionized ammonia (mg/L) | 0.5(b) | - | - | - | - | - | - | - | - | <0.01 |
| Selenium (mg/L) | 0.6 (c) | <0.0009 | <0.0009 | <0.0001 | 0.0001 | <0.0001 | <0.0001 | 0.0001 | 0.0001 | 0.0001 |
| Uranium (mg/L) | 2.5 (d) | 0.0034 | 0.0027 | 0.0039 | 0.0040 | 0.0017 | 0.0035 | 0.0035 | 0.0055 | 0.0048 |
| Molybdenum (mg/L) | N/A (e) | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | 0.0001 | 0.0001 | 0.0001 | <0.0001 |
- (a) Units are in milligrams per litre (mg/L) or becquerels per litre (Bq/L). Results show the mean of the concentrations for each month in one year.
- (b) Un-ionized ammonia was added to the MDMER in 2021.
- (c) This is the provincial limit that is not in the CNSC licence.
- (d) This is the provincial limit that is not in the CNSC licence. As discussed in section 3.1.1 of the full report, in the absence of a CNSC licence limit for uranium, the CNSC uses the interim objective for uranium of 0.1 mg/L as a benchmark to demonstrate the application of the ALARA and BATEA principles.
- (e) Refer to section 3.1.1 of the full report for an explanation of why no provincial or federal licence limits currently exist for molybdenum.
Human health
Monitoring doses
When ionizing radiation penetrates the human body or an object, it deposits energy. The energy absorbed from exposure to radiation is called a dose. The maximum dose limit to a member of the public is 1 millisievert (mSv) or 1000 microsieverts (μSv) per year. This is well below levels where any measurable health effect would occur.
To calculate the effective dose to people living near the site, Cameco assessed the risk to representative persons who had the potential to be the most exposed to contaminants. A total of 6 human receptor groups were identified as being the most exposed for potential radiological and hazardous contaminant exposures. The group included onsite and offsite workers and offsite residents.
Cameco also considered how a representative person located within or near the site could be exposed to potential radiological or hazardous substances, such as through breathing the air, being on the land, drinking and swimming in surface water, or eating plants, fish and wildlife near the facility.
The estimated annual radiological doses for the public near the Key Lake Operation for the 2013–2021 period have remained below the regulatory annual dose limit for the public. This indicates that radiological releases from the Key Lake Operation pose a negligible risk to human health (that is, potential risk to humans is similar to health outcomes in the general public).
Health studies
Reviewing and conducting health studies and reports is an important component of ensuring that the health of people living near or working in nuclear facilities is protected. When evaluating the health of populations living or working near the Key Lake Operation or similar facilities, CNSC staff consider the most recent international radiation epidemiology reports, the CNSC’s own information, and scientific publications – as well as various community, provincial, and national-level studies and reports.
Workers and the public are protected against radiation exposures from the Key Lake Operation. The population and community health studies and reports indicate that the most common causes of death among the population of northern Saskatchewan are injuries, cancer (predominantly seen in people that are 50 years of age and older), circulatory diseases, and respitory diseases. Lung cancer rates are greater in northern Saskatchewan compared to the provincial average and thus, lung cancer is the most common cause of cancer death in Indigenous Nations communities in northern Saskatchewan.
To get a snapshot of the health of the population living near the Key Lake Operation, CNSC staff looked at information and data from various sources. Based on exposure and health data, CNSC staff have not observed and do not expect to observe any adverse health outcomes to northern Saskatchewan communities or workers due to the presence of the Key Lake Operation.
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