Safety performance indicators

As part of its compliance verification program, licensees are required to report regularly to the CNSC on their performance against 25 safety performance indicators (SPIs).

For nuclear power plant (NPP) licensees, regulatory document REGDOC-3.1.1, Reporting Requirements for Nuclear Power Plants sets out the types of reports, their frequency and timeframes for reporting. SPI status reports are submitted to the CNSC on a quarterly basis.

Safety performance indicators include:

Collective radiation exposure

Indicates the total dose of ionizing radiation received by all individuals working at the NPP and its related facilities to monitor the performance in keeping NPP whole-body dose as low as reasonably achievable.

Personnel contamination events

Indicates the total personnel contamination events that occurred at the NPP and its related facilities.

Unplanned dose / Unplanned exposure

Indicates the estimated unplanned external whole-body exposure and unplanned internal tritium exposure received at the NPP and its related facilities.

Loose contamination events

Indicates the loose contamination events that occurred at the NPP and its related facilities.

Environmental releases – radiological

Indicates the airborne carbon-14 releases, airborne tritium releases and waterborne tritium releases at the NPP and its related facilities.

Spills

Indicates the total Category A, B and C spills that occurred at the NPP and its related facilities.

Mispositioning index

Indicates the mispositioning index value, which is an aggregate index of structures, systems and components off baseline condition or when a state changed as per instructions has an unexpected result, based on the number of mispositioning events and consequential or non-consequential mispositionings.

Number of unplanned transients

Indicates the number of reactor power transients due to equipment failures or operator errors while the reactor is not in a guaranteed shutdown state.

Reactivity management Index

Indicates the reactivity management index based on the severity of any reactivity management events.

Unit capability factor

Indicates progress in attaining high unit and industry energy production reliability, reflecting the effectiveness of plant programs and practices in maximizing available electrical generation, and providing an overall indication of how well plants are operated and maintained.

Unplanned capability loss factor

Indicates progress in minimizing outage time and power reductions that result from unplanned equipment failures or other conditions, reflecting the effectiveness of plant programs and practices in maintaining systems available for safe electrical generation.

Forced loss rate

Indicates progress in minimizing outage time and power reductions that result from unplanned equipment failures, human errors, or other conditions during the operating period (excluding planned outages and their possible unplanned extensions), reflecting the effectiveness of plant programs and practices in maintaining systems available for safe electrical generation when the plant is expected to be at the grid dispatcher's disposal.

Reactor trip rate (RTR)

Indicates the performance of unplanned automatic reactor shutdowns to provide an indication of how well a plant is operated and maintained.

Corrective maintenance backlog

Indicates corrective maintenance work required when a structure, system or component (SSC) has failed and can no longer perform its design function, reflecting the effectiveness of the maintenance program at the NPP and its related facilities.

Deficient maintenance backlog

Indicates deficient maintenance work required when structures, systems, or components have been identified as degrading but still capable of performing their design function, reflecting the effectiveness of the maintenance program at the NPP and its related facilities.

Deferral of preventive maintenance

Indicates deferred preventive maintenance that has received an approved technical justification for extension prior to its late date, reflecting the effectiveness of the maintenance program at the NPP and its related facilities.

Safety system test performance

Indicates successful completion of tests required by licence conditions, including those referenced in documents submitted in support of a licence application, to monitor performance in meeting regulatory and licensee availability requirements.

Preventive maintenance completion ratio

Indicates the fraction of preventive maintenance jobs to total maintenance jobs completed, to monitor performance in meeting preventive maintenance expectations.

Chemistry index

Indicates long-term unit control of important chemical parameters to monitor performance in meeting licensee's requirements in chemistry and to compare performance between Canadian CANDU units.

Chemistry compliance index (non-GSS and GSS)

Indicates unit control of chemical and radiochemical safety parameters, in both non-guaranteed and guaranteed shutdown states, to monitor performance in meeting regulatory and licensee requirements in chemistry control and to compare performance between Canadian CANDU units.

Conventional health and safety

Indicates the accident severity rate, accident frequency and industrial safety accident rate at the NPP to monitor performance in meeting nuclear industry standards in the area of worker safety and to compare Canadian NPP performance internationally.

Radiological emergencies performance index

Indicates a measurement of the performance of an NPP's emergency preparedness plan during radiological emergencies.

Emergency response organization drill participation index

Indicates the participation of emergency response organization personnel in drills, exercises or events within an NPP.

Emergency response resources completion Index

Indicates the level of verification of emergency response equipment and facilities dedicated to emergency preparedness at the NPP.

Low- and intermediate-level radioactive solid waste generated

Indicates the amount of low- and intermediate-level radioactive solid waste generated at the NPP.

Learn more about SPIs in the CNSC’s regulatory framework section 3.1 Reporting requirements, or for NPPs read REGDOC-3.1.1, Reporting Requirements for Nuclear Power Plants.