Functional Containment: Impact on Safety Approach and CSA N290.3 Update

Abstract of the technical presentation presented at:
16th International Conference on Nuclear Fuel
August 23-26, 2026

Prepared by:
Samuel Gyepi-Garbrah, Jana Ene, Mounia Berdaï
Canadian Nuclear Safety Commission

Labiba Tasnim
Power Generation and Delivery, CSA Group

Markus Piro
McMaster University

Glenn Harvel
Ontario Tech University

Muhammad Aamir
Nuclear consultant

Abstract:

The potential deployment of novel reactor designs in Canada, including small modular reactors that are non-water-cooled, introduces the concept of functional containment which may pose challenges in Canada and worldwide because it does not align with the “traditional concept of containment as a concrete structure.”

Internationally, functional containment is defined as “a barrier, or set of barriers taken together, that effectively limit the physical transport and release of radionuclides to the environment across a full range of normal operating conditions, anticipated operational occurrences and accident conditions.”

Under the current Canadian safety philosophy, the key physical barrier to radionuclide release during accidents is the containment system. Functional containment introduces a different approach by emphasizing the retention of radionuclides at their source in the fuel rather than reliance upon other physical barriers to ensure that dose consequences at the site boundary meets regulatory limits.

CSA N290.3, Requirements for the containment system of nuclear power plants, is a consensus standard that provides the framework for current nuclear containment design and is referenced in Canadian regulatory requirements.

This presentation will include an overview of the ongoing review of the new containment concept to CSA N290.3 requirements and will highlight the associated benefits and challenges of adopting a functional containment approach.  Work to date, including a CSA-hosted workshop, and the path forward to update CSA N290.3 will also be shared.

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.