The Canadian Nuclear Safety Commission’s Role in Facing Challenges related to Severe Accident Analysis associated with Small Modular Reactors

Abstract of the technical presentation presented at: The 11th European Review Meeting on Severe Accident Research Conference (ERMSAR 2024)
May 13-16, 2024

Author:
Samuel Gyepi-Garbrah
Canadian Nuclear Safety Commission

Abstract:

One of the roles of the Canadian Nuclear Safety Commission (CNSC) is to provide regulatory oversight of safe operation of nuclear power plants (NPPs) in Canada. The possible deployment of novel reactor designs, including those of Small Modular reactors (SMRs) that are not water-cooled have increased safety features but also poses challenges in Canada and worldwide.

In response to these challenges, proactive research development efforts are underway, including Phenomena Identification Ranking Tables (PIRT) for SMR designs, ATFs, in vessel retention (IVR) strategies, and strengthening and modernizing codes and regulations.

While CNSC has a robust and matured regulatory framework and requirements for oversight of severe accidents, water-cooled SMRs may also leverage previous large, water-cooled design provisions and lessons learned. For non-water technologies which presents larger gaps in knowledge, its smaller reactor power presents the opportunity of lesser safety risk due to no fuel degradation in the event of a severe accident. These technologies also claim novel engineered passive safety features, innovative containment concepts and alternative approaches that need to be considered from a regulatory perspective to demonstrate these safety functions in the event of a severe accident through adequate safety analysis.

Due to their small sizes, many designers propose that emergency planning zones may need to be reduced. However, for SMRs proposed for deployment in remote locations, the demonstration of adequate provisions for severe accident management and emergency planning zones is a critical factor for their regulatory approval and licensing by the CNSC. This is particularly important as timely assistance during severe accidents becomes crucial, especially when emergency services are not readily available nearby.

In this presentation, CNSC regulatory challenges and approach pertaining to the expectations of design provisions for severe accident and its mitigation for SMRs will be discussed.

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