Licensing of New and Advanced Reactors in Canada: Application of the Canadian PSA Requirements and Lessons Learned from New Nuclear Reactor Development

Abstract of the technical paper/presentation presented at:
International Conference on Topical Issues in Nuclear Installation Safety: Learning from the Past to Accelerate the Future
June 29 – July 3, 2026

Prepared by:
Chantal Morin, Katherine Gromek, Abderrazzaq Bounagui
Canadian Nuclear Safety Commission (CNSC)

Abstract:

Upon a growing interest in deployment of the next generation of nuclear power plants, regulators worldwide have adapted their regulatory frameworks over the past several years for application to advanced reactors new build projects. Likewise, the Canadian Nuclear Safety Commission (CNSC) comprehensively reviewed the regulatory framework over the past several years to learn from past successes and industry experience.

The CNSC’s regulatory framework combines prescriptive and performance-based approaches, offering flexibility as explained in REGDOC-3.5.3, “Regulatory Fundamentals”. This allows licensees to apply a graded, risk-informed approach and propose alternative approaches to compliance without compromising safety. Key safety objectives, environmental and radiological dose limits, and design requirements for new reactors are detailed in REGDOC-2.5.2, “Design of Reactor Facilities”.

The CNSC is currently engaged in the licensing review of the BWRX-300 SMR reactor deployment in Canada, the Darlington New Nuclear Project (DNNP). The practical application of the CNSC’s regulatory framework to the novel and first of a kind design features of this reactor revealed that some interpretations of requirements may need to be better defined. This paper presents how the CNSC’s regulatory philosophy and approach to Probabilistic Safety Assessment (PSA) and PSA applications were interpreted and applied to the BWRX-300 design in a risk-informed, performance-based manner, while upholding safety objectives and maintaining defense-in-depth principles.

The BWRX-300 PSA insights and lessons learned are discussed, along with novel aspects of PSA applications to support demonstration of alternative approaches to compliance with the CNSC regulatory requirements such as passive system reliability assessment, practical elimination, treatment of uncertainties associated with novel design features of advanced reactors, risk importance and safety classification of plant structures, systems and components (SSCs), etc. Application of best industry practices in PSA and use of the respective safety standards, codes, and guidance is also addressed.

To obtain a copy of the abstract’s document, please contact us at info@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.