Regulatory Role of PSA in Canada and lessons learned from its use in advanced reactor facilities

Abstract of the technical paper/presentation presented at:
17th International Conference on Probabilistic Safety Assessment and Management & Asian Symposium on Risk Assessment and Management
7-11 October, 2024

Prepared by:
Hayat Chatri, Michael Xu, Abderrazzaq Bounagui
Canadian Nuclear Safety Commission

Abstract:

In Canada, Probabilistic Safety Assessment (PSA) is formally integrated in the regulatory oversight of nuclear power plants throughout the whole life cycle.

The CNSC uses the information provided by the PSA to support the regulatory oversight program, to reexamine the efficacy of regulatory systems to enhance emergency preparedness and, to develop a risk-informed compliance verification process.

The CNSC regulatory document REGDOC-2.4.2, “Probabilistic Safety assessment (PSA) for Reactor Facilities” [1] sets high level requirements which call for the development of Level 1 and Level 2 PSA.

The CNSC’s current licensing strategy for the new builds is established based on the practice and experiences from the licensing of CANDU NPPs. As part of an application for a licence to construct, CNSC-REGDOC 1.1.2 “Licence Application Guide: Licence to Construct a Reactor Facility” requires that the application shall include a PSA conducted in accordance with REGDOC-2.4.2. It is expected that the PSA scope, at this stage, should be sufficient to provide preliminary risk results and insights, and to demonstrate that the high level PSA objectives established in REGDOC 2.4.2 are met.

In addition, CNSC-REGDOC 2.5.2 “Physical Design - Design of Reactor Facilities: Nuclear Power Plants” requires that the PSA shall be developed to demonstrate that the safety objectives including safety goals, as well as other safety system performance indicators have been achieved. It also requires that the application should describe how the results of the PSA have been used to identify plant vulnerabilities to severe accident, to support the SSC classification, and how the results of the PSA are used to provide insights into the severe accident management program. This paper aims to provide an overview of current status, application and the regulatory aspects of PSA in Canada. In addition, it will provide a brief background on the recent regulatory use of PSA for advanced reactor facilities and discuss its technical challenges and lessons learned.

To obtain a copy of the abstract’s document, please contact us at cnsc.info.ccsn@cnsc-ccsn.gc.ca or call 613-995-5894 or 1-800-668-5284 (in Canada). When contacting us, please provide the title and date of the abstract.