Technology Inclusive and Risk-Informed Reviews for Advanced Reactors: Comparing the US Licensing Modernization Project with the Canadian Regulatory Approach

Full report: (PDF) (Source: USNRC website)

Summary

In August 2019, the Canadian Nuclear Safety Commission (CNSC) and the U.S. Nuclear Regulatory Commission (NRC) signed a memorandum of cooperation (MOC) to increase collaboration on technical reviews of advanced reactor and small modular reactor technologies. The MOC builds on the joint memorandum of understanding signed in August 2017 and further strengthens the CNSC and NRC commitment to share best practices and experience from design reviews. Under this MOC, terms of reference were prepared to describe the administration of the cooperation and to facilitate the establishment of a program of work to accomplish specific cooperative activities.

As part of the program of work, a work plan was approved for exploring and seeking convergence on the regulatory approaches and guidance for applicants and regulatory reviewers in both countries.

The outcome of this work plan is a report documenting the results of the combined efforts of the CNSC and the NRC with a focus on:

• areas of commonalities and differences between the Canadian approach and U.S. approach regarding design and safety analysis.
• suggestions for future work needed for developing, to the extent practicable, shared technical requirements, guidance and review approaches.

The outcomes of this cooperative activity are intended to help each jurisdiction leverage information from each other in reviewing advanced reactor designs and further facilitate the capability to perform joint technical reviews of advanced reactor designs that have been submitted for review in Canada and the United States. The activity aims to promote a mutual understanding of each organization’s regulatory framework, with a focus mainly on safety analysis expectations which are fundamental to the safety case that would support a licence application.

Completion of this work demonstrates that the NRC and CNSC are ready to increase collaboration and facilitate joint technical reviews of advanced reactor and small modular reactor designs to ensure safety and to facilitate each agency’s regulatory reviews. Under the MOC, the NRC may consider insights from CNSC pre-licensing vendor design reviews and licensing review processes. The CNSC may also take into consideration NRC review results if an applicant proposes the construction and operation of a reactor using a design that is currently under review or that was previously reviewed by the NRC.

Both countries have recognized the increased use of risk information in regulatory decision making. As a result, the report focused on reviewing and comparing the technology-inclusive and risk-informed application approaches in each country. More specifically, it examined the TI-RIPB process developed as part of the Licensing Modernization Project (LMP) led by the U.S. nuclear industry, sponsored by the U.S. Department of Energy and endorsed by the NRC, and compared it with the requirements set out in CNSC regulatory requirements. In both approaches, vendors and applicants need to identify licensing basis events, to classify structures, systems and components, and to ensure adequate defence in depth, which are the fundamental building blocks for establishing the licensing basis and content of a licence application.

Regulatory frameworks and regulatory decision-making address legal, technical and policy matters. This work plan focused on technical matters and the ability to perform joint technical reviews. Legal and policy matters associated with each country’s regulatory framework were not addressed and would still need to be considered by each regulator when it makes its independent regulatory findings and decisions.

The Canadian and U.S. regulatory frameworks for the licensing and operation of nuclear power plants have been effective in ensuring the health and safety of the public, workers, and the environment, as defined by each nation’s regulatory body. There are many similarities in the CNSC’s and NRC’s overall licensing approaches with respect to safety objectives, fundamental safety functions, and the topical areas identified as the focus of each regulator’s safety review.

In addition, both the CNSC and NRC use technology-neutral and risk-informed approaches to demonstrate that the safety goals and objectives have been met for new design applications, while ensuring that each new design can adequately perform the fundamental safety functions of reactivity control, heat removal from the reactor core, and confinement of radioactive materials. Any differences in the CNSC- and NRC-accepted approaches, examined as part of this work plan, were considered to be at the implementation level of detail and to have no impact on the outcome of regulatory decisions necessary to ensure the health and safety of the public, workers, and the environment.

The report’s general conclusion is that there appears to be much common ground in safety case assessment reviews and acceptance criteria, which can be used as a foundation for technical reviews performed by one regulator (i.e., CNSC or NRC). These can be leveraged by either party (i.e., the CNSC or NRC), in order to inform independent regulatory findings and decisions required by law. Initial analysis indicates that the goal of performing joint technical reviews could be possible, and other work plans under this MOC will focus on piloting initial steps towards achieving that goal. CNSC and NRC collaboration on technical reviews is in the early stages; however, there have been early successes, and additional learning opportunities have been identified. This report includes suggestions for consideration by both the CNSC and NRC regarding future work that would help improve the overall efficiency and effectiveness of technical review collaborations, which may lead to achieving the ultimate goal of joint technical reviews.

Nothing in this report fetters the powers, duties or discretion of CNSC or NRC designated officers, CNSC or NRC inspectors, or the respective Commissions regarding making regulatory decisions or taking regulatory action. Nothing in this report is to be construed or interpreted as affecting the jurisdiction and discretion of the CNSC in any assessment of any application for licensing purposes under the Nuclear Safety and Control Act, its associated regulations or the Canadian Nuclear Safety Commission Rules of Procedure. Likewise, nothing in this report is to be construed or interpreted as affecting the jurisdiction and discretion of the NRC in any assessment of any application for licensing purposes under the Atomic Energy Act of 1954, as amended, its associated regulations and the NRC Management Directives. This report does not involve the issuance of a licence under section 24 of the Nuclear Safety and Control Act or under section 103 of the Atomic Energy Act of 1954. The conclusions in this collaborative report are of the CNSC and NRC staff.