Archived Web Page: RD–99.1: Reporting Requirements for Operating Nuclear Power Plants: Events

Preface

This regulatory document details the information that nuclear power plant (NPP) licensees are to report to the Canadian Nuclear Safety Commission (CNSC) to support the conditions of applicable operating licences. The document gives the types of event reports, the frequency and the applicable timeframe for reporting (reporting timeframes are determined by the safety significance of the event).

This regulatory document replaces S-99, Reporting Requirements for Operating Nuclear Power Plants, published in March 2003.

This regulatory document has a companion guidance document entitled GD-99.1, Guide to the Reporting Requirements for Operating Nuclear Power Plant: Events. GD-99.1 contains guidance, explanatory information, forms and templates provided by the CNSC to assist users in meeting the requirements of RD-99.1.

This document is a part of a suite of regulatory documents providing event and routine compliance monitoring reporting requirements, and the public information and disclosure requirements for nuclear facilities. Each regulatory document is accompanied by a complementary guidance document.

Key principles and elements used in developing this document are consistent with national and international standards.

Nothing contained in this document is to be construed as relieving any licensee from pertinent requirements. It is the licensee’s responsibility to identify and comply with all applicable regulations and licence conditions.

Table of Contents

1.0 Introduction

1.1 Purpose

The purpose of this regulatory document is to set out the Canadian Nuclear Safety Commission (CNSC) requirements for unscheduled reporting of events by operating nuclear power plants (NPPs).

1.2 Scope

The requirements of this regulatory document are in addition to those in the Nuclear Safety and Control Act (NSCA) and its applicable regulations.

The reporting requirements specified in this document are consistent with safety significance of situations or events. The requirements include a reporting process and licensee grading of events that have a range of consequences.

This document does not include scheduled reporting to support compliance monitoring.

1.3 Relevant legislation and regulations

The following provisions of the NSCA, the General Nuclear Safety and Control Regulations (GNSCR), the Class I Nuclear Facilities Regulations (CINFR), the Radiation Protection Regulations (RPR), the Nuclear Substances and Radiation Devices Regulations (NSRDR), the Packaging and Transport of Nuclear Substances Regulations (PTNSR) and the Nuclear Security Regulations (NSR) are relevant to this document:

• Subsections 24(1) and 24(5) of the NSCA give the CNSC the authority to establish classes of licences and to include in those licences any terms or conditions that the CNSC considers necessary for the purposes that are laid out in section 3 of the NSCA. Pursuant to this authority, the CNSC has established operating licences for NPPs and, for the purposes of the NSCA, proposes to incorporate this document into these licences.
• Paragraph 27(b) of the NSCA requires every licensee and every prescribed person to make the prescribed reports and to file them in the prescribed manner. In accordance with section 2 of the NSCA, “prescribed” means prescribed by regulation of the CNSC. Accordingly, this paragraph obliges licensees who operate an NPP, to file reports in accordance with any relevant requirements established by the CNSC.
• Subsection 9(4) of the GNSCR requires persons who carry on an activity without a licence in accordance with subsections 9(1) and 9(2) of the GNSCR to immediately notify the CNSC.
• Section 15 of the GNSCR stipulates that every licensee shall notify the CNSC of (a) the persons who have authority to act for the licensee in the licensee’s dealings with the CNSC; (b) the names and position titles of the persons who are responsible for the management and control of the licensed activity; and (c) any change in the information referred to in (a) and (b) within 15 days after the change occurs.
• Section 28 of the GNSCR outlines the reporting requirements and procedure for record keeping and their disposal as required by the Act, the regulations made under the Act or a licence. A person who notifies the CNSC in accordance with subsection (2) shall file the record, or a copy of the record, with the CNSC at its request.
• Sections 29, 30, and 31 of the GNSCR specify general, safeguards and record deficiency reporting requirements.
• Section 32 of the GNSCR requires every report to include the name and address of the sender as well as the date on which it was completed. The section also defines the date of the filing of a report to be the date that the report is received by the CNSC.
• Paragraph 6(2)(c) of the RPR requires a licensee (including an operator of an NPP) to notify the CNSC, within the period specified in the licence, when the licensee becomes aware that an action level referred to in the licence has been reached.
• Paragraph 16(a) of the RPR requires that, when a licensee becomes aware that a dose of radiation received by and committed to a person, organ or tissue may have exceeded an applicable dose limit prescribed by section 13, 14 or 15, the licensee shall immediately notify the person and the CNSC of the dose. In accordance with paragraph 16(e) of the same regulations, the licensee shall also report to the CNSC, within 21 days after becoming aware that the dose limit has been exceeded, the results of the investigation or on the progress that has been made in conducting the investigation in accordance with paragraph 16(c).
• Subparagraphs 6(k)(ii) and 6(k)(iii) of the CINFR require licensees to notify and report information on any accidental or imminent accidental releases to off-site authorities. Paragraphs 12(1)(e) and (f) of the GNSCR sets out obligations consistent with such notification and reporting.
• Subsections 18(3) and 30(2) of the NSRDR capture situations related to exposure devices or sealed sources that require notification and reporting. Sections 35 and 38 of the same regulations are related to notifying and reporting situations for nuclear substances and radiation devices.
• Sections 19, 21 and 22 of the PTNSR provide the notification and reporting requirements for events concerning transportation of nuclear substances and radiation devices.
• Subsection 7.5(4) of the NSR pertains to threat and risk assessment reporting to the CNSC within 60 days after completion of the assessment. In addition, sections 21, 36 and subsection 44(2) provide requirements for notification for other nuclear security–related events.

2.0 Reporting Requirements

2.1 General requirements

The licensee shall provide reports on events in the manner and within the timeframe specified in this section. This section contains information regarding what is to be reported and the timeframes for reporting this information.

The licensee shall manage its reporting requirements under this regulatory document in conjunction with its other reporting requirements as specified in the NSCA, the regulations, the licence and the licence condition handbook (as applicable). The licensee shall describe the process for reporting and manage reporting under its management system.

2.2 Requirements for reporting

2.2.1 Situations and events that require preliminary and detailed reports

The licensee shall submit preliminary reports and detailed reports for situations or events identified in this section. The timeframe to submit these reports depends on the safety significance of the situations or events as outlined in sections 2.2.1.1 and 2.2.1.3.

Situations or events requiring reports are found in table 1. The situations and events are aligned with the CNSC safety and control areas (SCAs) listed in table 2.

2.2.1.1 Submitting preliminary reports

The licensee shall submit preliminary reports as detailed in this subsection. The timing of these reports reflects their safety significance classification grading levels as follows:

1. high safety significance situations or events require an immediate preliminary report
2. medium safety significance situations or events require a next normal business day preliminary report
3. low safety significance events require a preliminary report within five normal business days

“Immediate” means reporting to the CNSC as soon as the licensee becomes aware that the situation or event is reportable, and initiating any required response actions.

“Next normal business day” means the licensee’s first normal business day after the licensee becomes aware that the situation or event is reportable.

“Within five normal business days” means the licensee’s fifth normal business day after the licensee becomes aware that the situation or event is reportable.

The licensee shall determine the safety significance for the situations or events specified in table 1. Preliminary reports are to be submitted to the CNSC according to the timeframes given above.

Event safety significance classification grading shall be utilized to determine the regulatory response action to be taken by CNSC.

A methodology for determining risk and safety significance and reporting times based on safety significance is provided in GD-99-1. A licensee’s risk and safety significance determination process can be utilized if consistent with this methodology.

2.2.1.2 Contents of preliminary reports

The preliminary reports shall contain the following information where applicable and available:

1. date, time and circumstances of the discovery of the situation or event
2. date and time of the onset and the duration of the situation or event, or a best estimate thereof
3. identification of the affected NPP and associated reactor units and structures
4. structures, systems, components, functions or personnel affected by the situation or event
5. safety significance level of the situation or event
6. description of the occurrence and consequences of the situation or event, and any actions that the licensee has taken or proposes to take with respect to the situation or event
7. description of any exposure of a person to radiation as a consequence of the situation or event

2.2.1.3 Submitting detailed reports

The licensee shall submit detailed reports of situations or events described in table 1 of this document within 60 days of submitting the preliminary report. Extensions for specific events may be requested. Preliminary reports for low safety significance situations or events do not require a detailed report if there is no additional information. However, additional information may be necessary for regulatory closeout.

2.2.1.4 Contents of detailed reports

The contents of the detailed reports for a particular table 1 situation or event being reported are specified in tables 3 and 4.

Table 3 identifies detailed reports that require a summary of the root-cause analysis. For specific events, CNSC may request a root-cause analysis report.

Sections 27 and 44 of the NSCA and sections 29 and 30 of the GNSCR contain requirements where the submission time for full reports can be extended by the terms of a licence condition. This regulatory document, when referenced in an operating licence, requires the submission of the full reports for these requirements within 60 days of submitting the preliminary report.

For full reports submitted pursuant to sections 29 to 31 of the GNSCR, the licensee shall also include the information specified in Detailed Report (1), as specified in table 3.

2.2.2 Situations and events that require notifications and/or reports

2.2.2.1 The reaching of an action level

When a licensee becomes aware that an action level referred to in the licence has been reached, and where that action level is required for the purpose of protecting workers and members of the public from unreasonable radiological risk resulting from the normal operation of the licensed facility and/or releases of radionuclides into the environment, the licensee shall:

1. notify the CNSC within five normal business days
2. within 60 days of the date that the licensee became aware that an action level has been reached, file a report with the CNSC that:
1. describes the results of the investigation conducted to establish the cause of reaching the action level
2. describes the actions identified and taken to restore the effectiveness of the radiation protection program implemented in accordance with section 4 of the RPR
3. identifies any missing information and describes how and when the missing information will be provided to the CNSC
4. includes the name and address of the sender of the report, the date of completion of the report, and the name and signature of the designated representative of the licensee

2.2.2.2 Performance and status of certified personnel reports

The licensee shall file with the CNSC, within 21 days, a report of the occurrence of the following situations or events:

1. removal of a certified person from the duties of the position for which the person is certified by the CNSC
2. reinstatement of a certified person to the duties of the position for which the person is certified by the CNSC
3. temporary assignment of a certified person to an operationally focused or non-operationally focused position that does not require a person certified by the CNSC; any temporary assignments in excess of six months require reporting

The report shall contain the following information if it is applicable to the situation or event being reported:

1. full name and position of the certified person
2. date of the removal of a certified person from a position for which the person has been certified, and the reasons for the removal of the certified person
3. date of any reinstatement of a certified person to the duties of a position for which the person is certified by the CNSC, and the remedial action taken prior to the reinstatement
4. date of any temporary assignment of a certified person to an operationally focused or non-operationally focused position that does not require a person certified by the CNSC
5. number of complete shifts performed by a certified person during the previous two calendar quarters, the reasons for not meeting the minimum requirements, and the remedial actions being taken
6. name and address of the sender of the report, the date of completion of the report, and the name and signature of the designated representative of the licensee

2.2.2.3 Reports of problems identified by research findings or revised analyses

When a licensee becomes aware, through research findings or new or revised safety analyses, of a problem or potential problem that represents a hazard or potential hazard to the health and safety of persons, security or the environment, or that may be different in nature, greater in probability or greater in magnitude than was previously represented to the CNSC in licensing documents, the licensee shall:

1. notify the CNSC within 21 days of becoming aware of the problem or potential problem, and establish with the concurrence of the CNSC a timeframe for submitting a report
2. within the established timeframe, file with the CNSC the report

The report shall be filed for problems or potential problems, including:

1. final safety analysis report containing an assumption, input, analytical method or safety analysis result that is or may be invalid
2. limit, defined in the NPP licensing documents (or in appendices to these documents), that is or may be inadequate to assure safety
3. analysis, from which a limit in a licensing document was derived, that may be invalid or uncertain such that the margin of safety may be less than predicted
4. defined specifications of a special safety system or of a safety-related system of an NPP that are or may be invalid
5. NPP licensing document containing an error that, if accepted, relied or acted upon as being valid, could give rise to increased risks to the health and safety of persons, security or the environment
6. measures in place for the purpose of protecting the environment from the operating impacts of an NPP that are or may be inadequate
7. discovery of a material or component condition that changes or renders inaccurate the submission made to CNSC staff in support of continued operation of a component or system important to safety

The report shall further include the following information, where applicable and available:

1. identification of the NPP and reactor unit that is or may be affected by the problem or potential problem
2. identification of structures, systems, components or functions of the NPP that are or may be affected by the problem or potential problem
3. description of the problem or potential problem and its actual or potential safety significance
4. summary of the research or analysis that led to awareness of the problem or potential problem
5. evaluation of the degree of any impairment of a special safety system or safety-related system
6. description of the corrective actions that have been taken, or that are proposed to be taken, to address the problem or potential problem
7. name and address of the sender of the report, the date of completion of the report, and the name and signature of the designated representative of the licensee

Tables

Table 1: Situations and Events Requiring Reports

#	Description	SCAs (see Table 2)
Health and safety
1.	An event that could have caused a reportable dose of radiation under the RPR but, due to fortuitous circumstances rather than to approved procedures, did not.	1–7
2.	The intentional misuse, by persons, of anything that is intended to protect the health and safety of persons or the environment from risks associated with the operation of the NPP.	1–3, 5, 7, 8
Process failures
3.	A serious process failure.	1–10, 12, 13
4.	A potential serious process failure.	1–10, 12, 13
5.	A situation or event requiring a nuclear power reactor shutdown in accordance with the licensing basis.	1–7, 9, 10
6.	An event that results in an acute and unrecoverable loss of more than 100 kg of heavy water.	1-7, 9
Safety systems
7.	An actuation, at any power level, of one or both shutdown systems, except where: a) the actuation occurs while the reactor unit is in a guaranteed shutdown state and does not indicate that the shutdown guarantee has failed, or b) the actuation was deliberate as required for testing purposes	1–7, 9, 10
8.	An actuation of an emergency core cooling system or subsystem as a consequence of an initiating parameter exceeding a setpoint.	1–7, 9, 10
9.	A spurious operation or a failure of a device at the final point of control for the purpose of separating the circuits of the heat transport system from the emergency core cooling systems.	1–7, 9, 10
10.	An actuation of a containment system or subsystem as a consequence of an initiating parameter exceeding a setpoint.	1–7, 9, 10
11.	A degradation of a special safety system or standby safety-related system that: a) prevents special safety systems or standby safety-related systems from performing their safety-related function as intended, or meeting their defined specifications, or b) may result in a hazard to the health and safety of persons	1–10
Pressure boundaries
12.	A pressure boundary degradation of a safety-related system. A non-safety-significant deformation or crack, a pinhole that does not have the potential to significantly impair the operating ability of the system, and a degradation that causes a leak that does not exceed a limit specified in the licensing basis are all exempted from these reporting requirements. Degradations to be reported include: a) ruptures b) safety significant deformation or cracks c) formation of pinholes due to degradation that have the potential to significantly impair the operating ability of the system d) degradations that cause a leak that exceeds a limit specified in the licensing basis or in this regulatory document e) changes in the size, rating or material properties of any part of a pressure boundary that was not allowed for in the design of the boundary f) local or general reductions in wall thickness beyond that allowed by the applicable pressure vessel code, standard or act under which the safety-related system’s pressure boundary was registered (or could have been registered) g) degradations of overpressure protection equipment that caused or would have caused the equipment to fail to operate in accordance with the overpressure protection report or another licensing document, other than a relief device that activates above its maximum setpoint during testing but below the hydrostatic test pressure of the associated system	1–10
13.	A transient load condition that exceeds a relevant design condition of a pressure boundary, or that exceeds Level B service limits for a nuclear component that has been designed in accordance with Section III, Division 1, Subsection NB of the ASME Boiler & Pressure Vessel Code.	1–10
14.	An analysis related to a pressure boundary of a safety-related system that concludes that an applicable limit that is specified in the associated design analyses, the design and inspection codes, or the design and inspection standards, has been exceeded.	1–6
15.	A safety significant pressure boundary failure or leak in a system that: a) contains radioactive or hazardous substances in high enough concentrations to pose a hazard to unprotected personnel b) is of sufficient pressure or temperature to pose a hazard to unprotected personnel c) results in a leak of any material that impinges upon any electrical component, or d) results in a leak that causes damage or flooding that affects the safe operation of the plant	1–10
16.	A situation where the configuration of a valve or other device associated with a pressure boundary contravenes relevant requirements in the overpressure protection report or another licensing document.	1–6
Reactor and turbine control
17.	A reduction below defined specifications of the effectiveness of a system for: a) controlling reactor power b) controlling the pressure and inventory of the primary heat transport system, or c) protecting the steam turbine	1–6
Security
18.	A transfer or disclosure of prescribed information that is not permitted by the NSCA and the regulations made under the NSCA.	1–3, 12, 13
19.	An attempted or actual breach against electronic systems and/or subsystems necessary for safety, security and emergency preparedness of the NPP.	1–3, 12
20.	A security incident in the form of: a) a misuse of security-related equipment b) the discharge of firearms or other prohibited weapons, or c) a threat made against the NPP	1–3, 12
Emergency
21.	A situation or event that requires the implementation of the nuclear emergency plan.	1–10, 12, 13
22.	A declaration of an alert or emergency within the NPP where personnel or resources are mobilized by the licensee in response to an unexpected occurrence that creates a hazard to the safe operation of the NPP, to the environment or to the health and safety of persons.	1–10, 12, 13
External events
23.	An earthquake having a magnitude that is equal to or greater than that of the design basis earthquake (DBE), or any earthquake that occurs within 500 km of the NPP and is greater than magnitude 5 on the Richter scale.	1–10
24.	The occurrence of any unusual external events at the site that resulted in operating transients at the NPP.	1–10
Internal fires
25.	The occurrence of a fire at the NPP.	1–6, 10
Testing and monitoring
26.	A failure to monitor or control the release of a nuclear substance as required by the licence.	1–7, 9
27.	A failure to monitor or control the release of a hazardous substance as required by any federal or provincial regulation, or a licence, permit or certificate issued by a municipal, provincial or other federal authority.	1–7, 9
Hazards not addressed in licensing documents
28.	A situation or event arising from the NPP operating experience that reveals a hazard to the health and safety of persons, to security or to the environment that either may be or is determined to be different in nature, greater in probability or greater in magnitude than was previously represented to the CNSC in the licensing documents, including the following: a) special safety system that does not meet its defined specifications b) reactor that is operating in a state that was not considered in the safety analysis c) occurrence of an event of a type that was not considered in the safety analysis d) unexplained or unexpected behaviour of a reactor core e) event where two or more systems or components that were assumed in the safety analysis to be mutually independent are, in fact, interdependent f) mistake in a licensing document that, if relied upon or acted upon, would increase the risk to the health and safety of persons, to security or to the environment g) release of a nuclear substance in a quantity or rate greater than that predicted in the safety analysis, or h) determination that actual field configuration is not consistent with assumptions made in the safety analysis	1–14
Abnormal or unplanned change in power level of a reactor
29.	An abnormal or unplanned change in the power level of a reactor, whether the change was induced by the operator or the reactor regulation system (setback or stepback in power).	1–7, 9, 10
Other reportable situations and events
30.	For other situations or events that are not otherwise specified in this document but have regulatory implications, the licensee shall classify and report the event according to the safety significance level.	1–14

Table 2: Safety and Control Areas (SCAs)

#	Safety and Control Area
1.	Management system
2.	Human performance management
3.	Operating performance
4.	Safety analysis
5.	Physical design
6.	Fitness for service
7.	Radiation protection
8.	Conventional health and safety
9.	Environmental protection
10.	Emergency management and fire protection
11.	Waste management
12.	Security
13.	Safeguards
14.	Packaging and transport

For a situation or event that is determined to need a detailed report, the following information is required for items (1) to (11) and (13) to (30) of table 1:

Table 3: Contents of Detailed Report (1)

#	Required Information
1.	Name of the nuclear facility, reactor unit number (if applicable), licence number and licensee reference report number.
2.	The information that was contained in the preliminary report and any updates that are necessary to better reflect new information, with the changes from the preliminary report clearly indicated.
3.	The reporting provision in table 1 that best describes the situation or event.
4.	A description of the condition of the site where the situation or event has occurred and the operating conditions of any power reactor unit involved in the situation or event, including the power level at which the reactor was operating immediately prior to the situation or event.
5.	A description of actions taken in immediate response to the situation or event.
6.	The names of municipal, provincial or federal authorities that were notified of the situation or event.
7.	A detailed description of the occurrence of the situation or event, including the associated circumstances, causes and consequences, and relevant conclusions or findings established by the investigative process.
8.	The safety significance of the situation or event, including if an actuation of either shutdown system occurred.
9.	An evaluation of the degree of impairment of special safety systems or of standby safety-related systems.
10.	A summary of the root-cause analysis, using a recognized methodology, for: a) table 1 (7), (8) and (10) other than for a box up; table 1 (15) if it results in a declaration of an emergency condition, requires the implementation of abnormal incident procedures, or results in harm to a person; or table 1 (21) and (22) for a declaration of an emergency only, or b) events where the licensee’s internal processes instigates a root-cause analysis.
11.	The measured or estimated doses to NPP personnel and the public as a consequence of the situation or event.
12.	A description of the effects on the environment, on the health and safety of persons, and on national or international security that have resulted or may have resulted.
13.	The conclusions reached and actions taken as a result of any review of a comparable situation or event.
14.	A description of the actions taken or proposed to correct the situation or event and to prevent a recurrence of the situation or event, including those actions that result from a root-cause analysis, and a timetable for completing the actions proposed to be taken.
15.	The comments and recommendations of NPP management, including comments on the appropriateness of the actions taken by operating staff.
16.	The name and address of the sender of the detailed report, the date of completion of the report, and the name and signature of the designated representative of the licensee

For a situation or event that is determined to need a detailed report, the following information is required for item (12) of table 1:

Table 4: Contents of Detailed Report (2)

#	Required Information
1.	Name of the nuclear facility, reactor unit number (if applicable), licence number and licensee reference report number.
2.	The information that was contained in the preliminary report and any updates that are necessary to better reflect new information, with the changes from the preliminary report clearly indicated.
3.	The reporting provision in table 1 that best describes the situation or event.
4.	The date of discovery.
5.	The reported date.
6.	Identification of affected systems.
7.	Identification of equipment and components involved.
8.	Material type and code classification of the affected component.
9.	Design and hydrostatic test pressure of the system.
10.	Magnitude, size or quantification of the degradation or fault (e.g., deformation shape and size, crack length and depth, material, approximate leak rates, deviation from setpoint).
11.	Causes and circumstances of the degradation.
12.	Consequences and effects of the degradation.
13.	Code, standard or methodology used to assess the significance of the degradation.
14.	Measures taken or planned to correct, reduce or avoid reoccurrence of the situation.
15.	The name and address of the sender of the detailed report, the date of completion of the report, and the name and signature of the designated representative of the licensee.

Glossary

action level 

A specific dose of radiation or other parameter that if reached, may indicate a loss of control of part of a licensee’s radiation protection program and triggers a requirement for specific action to be taken.

barrier

A physical obstruction that prevents or inhibits the movement of people, radionuclides or some other phenomenon (e.g., fire), or provides shielding against radiation.

box up (or btn up)

Measures taken to prevent the escape of radioactive material beyond a containment envelope.

Canadian Nuclear Safety Commission (CNSC)

For the purposes of this document, CNSC means the Commission or a person who is authorized by the Commission.

certified person

Person named on a certificate issued by the CNSC or a designated officer authorized by the CNSC who attests that the person is competent to carry out the duties of a given position referred to in the NPP licence.

defence in depth

A hierarchical deployment of different levels of diverse equipment and procedures to prevent the escalation of anticipated operational occurrences and to maintain the effectiveness of physical barriers placed between a radiation source or radioactive material and workers, members of the public or the environment, in operational states and, for some barriers, in accident conditions. There are five levels of defence in depth:

1. Level 1: prevention of abnormal operation and failures
2. Level 2: control of abnormal operation and detection of failures
3. Level 3: control of accidents within the design basis
4. Level 4: control of severe plant conditions, including prevention of accident progression and mitigation of the consequences of severe accidents
5. Level 5: mitigation of radiological consequences of significant releases of radioactive material

defined specifications

The criteria, as set out in the NPP licensing documents, that specify the capability or performance level that a system, structure or component of the NPP must possess or attain so that the plant will be able to function effectively and reliably in accordance with its safety targets.

design basis earthquake (DBE)

As defined in the Canadian Standards Association publication CSA-N289.1-08, General Requirements for Seismic Design and Qualification of CANDU Nuclear Power Plants.

event

Any occurrence unintended by the operator, including operating error, equipment failure
or other mishap, and deliberate action on the part of others, the consequences or potential consequences of which are not negligible from the point of view of protection or safety. In this document, the words ‘event’ and ‘situation’ are considered to be interchangeable.

environment

The components of the earth, including:

1. land, water and air, including all layers of the atmosphere
2. all organic and inorganic matter and living organisms
3. the interacting natural systems that include components referred to in (a) and (b) above

external event

Any event that proceeds from the environment and can cause a plant’s structures, systems or components to fail. External events include, but are not limited to, earthquakes, floods and hurricanes.

fire

Uncontrolled combustion, not restricted to open flame, that causes personal injury, death or property damage, or results in the mobilization of the emergency response team where mitigation action was needed to extinguish the combustion.

flooding

Liquid present in an area in a quantity exceeding what would normally be expected and that has an impact on the safe operation of the NPP.

human factors

Factors that influence human performance as it relates to the safety of the nuclear power plant, including activities during design, construction, commissioning, operation, maintenance and decommissioning phases.

impairment 

A failure such that the safety-related system would operate with reduced redundancy or margin of safety, or would fail to meet its design intent. Level 1 impairment is used to describe a system state that is impaired to the extent that it would provide inadequate protection. Level 2 impairment is used to describe a system state that is impaired to the extent that it would provide some, but not complete, protection for a worst-case process failure. Level 3 impairment is used to describe a system state where the level of redundancy or margin of safety is reduced, but the system is still fully capable of meeting its design intent.

initiating event

An event that initiates a sequence of events that could lead to a severe accident in the absence of action by a system important to safety, or an event involving a system important to safety that initiates a sequence of events that could have lead to a severe accident if other systems important to safety had not acted

initiating parameter

The physical property being measured or monitored by the triggering device for a special safety system or its subsystems.

licensing basis

For a regulated facility or activity, the information demonstrating that the applicant is qualified to carry out the authorized activity, and appropriate provisions are in place for the protection of the environment, the health and safety of persons, and the maintenance of national security and measures required to implement international obligations to which Canada has agreed. This information consists of the applicable legislative and regulatory requirements, the facility’s or activity’s licence and the documents and conditions cited in that licence, and the licence application and the documents submitted in support of that licence application.

licensing document

A document listed or referred to in a licence issued by the CNSC.

nuclear power plant

A fission-reactor installation that has been constructed to generate electricity on a commercial scale. An NPP is a Class IA nuclear facility as defined in the Class I Nuclear Facilities Regulations.

potential serious process failure

An event that could have become a serious process failure but, due to fortuitous circumstances rather than to design provisions or approved procedures, did not.

pressure boundary

A boundary of a pressure-retaining vessel, structure, system or component of a nuclear or non-nuclear system, where the vessel, structure, system or component is registered (or eligible for registration) under boiler or pressure-vessel legislation, or is part of the NPP containment system.

pressure boundary degradation

A degradation of a pressure boundary that exceeds any relevant limit specified in the applicable design analysis, design codes or standards, or inspection codes or standards.

risk

The chance of injury or loss, defined as a measure of the probability and severity of an adverse effect (consequences) to health, property, the environment or other things of value; mathematically, it is the probability of occurrence (likelihood) of an event multiplied by its magnitude (severity).

root-cause analysis

An objective, structured, systematic and comprehensive analysis that is designed to determine the underlying reason(s) for a situation or event

safety analysis

Analysis by means of appropriate analytical tools that establishes and confirms the design basis for the items important to safety, and ensures that the overall plant design is capable of meeting the acceptance criteria for each plant state.

safety-related system

As defined in the Canadian Standards Association publication CSA-N285.0-08, General requirements for pressure-retaining systems and components in CANDU nuclear power plants, that is referenced in the nuclear power plant licence.

safety significance

Refers to the significance of a discovery or issue with respect to the impact on meeting the fundamental nuclear safety objectives as defined by the IAEA. In general, a discovery or event has safety significance if it denotes a deviation away from the safety case accepted in the licence in a direction detrimental to safety, such as:

1. reducing margins to, or exceeding, the accepted limits
2. increasing risk
3. impairments (various degrees) of the special safety systems or of the safety functions for accident mitigation
4. human factors issues
5. events causing radioactive releases and spills of hazardous substances, injuries to workers or public, etc.

serious process failure

A failure of a process structure, system or component that leads to a systematic fuel failure or a significant release from the NPP, or that could have led to a systematic fuel failure or a significant release in the absence of action by any special safety system.

significant release

A release of radioactive material that results in an effective dose, received by or committed to a typical member of the critical group, in excess of 0.5 mSv (50 mrem).

situation

See “event”.

special safety system

One of the following systems of an NPP: shutdown system no.1, shutdown system no. 2, the containment system or the emergency core cooling system.

standby safety-related system

Those poised systems that provide for the ultimate reactor cooling following design basis events (e.g., emergency power supply and emergency water supply).

systematic fuel failure

Fuel that has no defect prior to an event, or fails or exceeds the fuel integrity criteria defined in the licensing documents as a result of the event.

systems important to safety

Structures, systems and components of the NPP associated with the initiation, prevention, detection or mitigation of any failure sequence that have the most significant impact in reducing the possibility of damage to fuel, associated release of radionuclide, or both.

Additional Information

The following legislation (statutes and regulations) is relevant to this regulatory document:

• Nuclear Safety and Control Act, S.C., 1997, c. 9
• General Nuclear Safety and Control Regulations, SOR/2000-202
• Radiation Protection Regulations, SOR/2000-203
• Class I Nuclear Facilities Regulations, SOR/2000-204
• Nuclear Substances and Radiation Devices Regulations, SOR/2000-207
• Packaging and Transport of Nuclear Substances Regulations, SOR/2000-208
• Nuclear Security Regulations, SOR/2000-209
• Interpretation Act, R.S.C. 1985, c. I-21

The following documents provide additional information pertaining to reporting requirements for operating NPPs:

• GD-99.1, Guide to the Reporting Requirements for Operating Nuclear Power Plants: Events, Canadian Nuclear Safety Commission, 2011 (TBC)
• CMD 05-H32, Information and Recommendations from Canadian Nuclear Safety Commission Staff Regarding Licence Amendments to Strengthen Regulatory Controls on Sealed Sources, Canadian Nuclear Safety Commission, 2005
• P-325, Nuclear Emergency Management, Canadian Nuclear Safety Commission, 2006
• S-294, Probabilistic Safety Assessment (PSA) for Nuclear Power Plants, Canadian Nuclear Safety Commission, 2005
• S-98 Rev-1, Reliability Programs for Nuclear Power Plants, Canadian Nuclear Safety Commission, 2005
• S-210, Maintenance Programs for Nuclear Power Plants, Canadian Nuclear Safety Commission, 2007
• RD-204, Certification of Persons Working at Nuclear Power Plants, Canadian Nuclear Safety Commission, 2008
• G-225, Emergency Planning at Class I Nuclear Facilities and Uranium Mines and Mills, Canadian Nuclear Safety Commission, 2001
• G-274, Security Programs for Category I or II Nuclear Material or Certain Nuclear Facilities, Canadian Nuclear Safety Commission, 2003
• G-208, Transportation Security Plans for Category I, II or III Nuclear Materials, Canadian Nuclear Safety Commission, 2003
• S-296, Environmental Protection Policies, Programs and Procedures at Class I Nuclear Facilities and Uranium Mines and Mills, Canadian Nuclear Safety Commission, 2006
• CSA N285.0/N285.6 series, General Requirements for Pressure Retaining Systems and Components in CANDU Nuclear Power Plants/Material Standards for Reactor Components for CANDU Nuclear Power Plants, Canadian Standards Association
• CSA N285.4, Periodic Inspection of CANDU Nuclear Power Plant Components, Canadian Standards Association
• CSA N285.5, Periodic Inspection of CANDU Nuclear Power Plant Containment Components, Canadian Standards Association
• CSA N286.0, Overall Quality Assurance Program Requirements for Nuclear Power Plants, Canadian Standards Association
• CSA N286-05, Management System Requirements for Nuclear Power Plants, Canadian Standards Association
• CSA N287.7, In-service Examination and Testing Requirements for Concrete Containment Structures in CANDU Nuclear Power Plants, Canadian Standards Association
• CAN/CSA N289.5, Seismic Instrumentation Requirements for CANDU Nuclear Power Plants, Canadian Standards Association
• ANR1.OR, Implementing Guideline 19.1, World Association of Nuclear Operators, 1996
• ISO 17025, Quality Manual Template, International Organization for Standardization, 2005
• ASME Boiler & Pressure Vessel Code, Section III, Division 1, Rules for Construction of Nuclear Power Plant Components - Subsection NB - Class 1 Components, American Society of Mechanical Engineers
• TS-R-1, Regulations for the Safe Transport of Radioactive Material, International Atomic Energy Agency, 2009