On March 31st, 2023, the Canadian Nuclear Safety Commission (the "CNSC") published an update to its REGDOC-3.5.3, Regulatory Fundamentals. This regulatory document details fundamental information for regulating nuclear activities in Canada and has been updated to provide further guidance regarding the use of risk-informed decision making1 and the graded approach2 for regulating small modular nuclear reactors (SMRs). This regulatory update represents a significant step for deploying SMRs in Canada.
The CNSC has updated REGDOC-3.5.3, Regulatory Fundamentals to include "Appendix D: Risk-Informed Regulating". Appendix "D" provides insight into how the CNSC applies the graded approach to new and innovative technologies. This update is consistent with the movement of the nuclear power industry towards SMRs and is planned to provide proponents greater flexibility for demonstrating the safety of their designs.
Appendix "D" explains that the CNSC will apply the graded approach with greater flexibility to consider other characteristics of SMR designs which may not be expressly permitted under its other regulations. These characteristics include fuel design, type and source; the amount of enrichment of fissile and fissionable material; presence of radioactive and hazardous sources; and the uncertainty of the regulated activity.
Most notably, the graded approach may now permit less stringent safety requirements to achieve fundamental safety functions where the risk is minimal. This is significant since SMRs may not present the same risks as large commercial reactors, which Canada's regulations have, up until recently, been tailored for. Hence, this revision permits SMR proponents to avoid redundant safety precautions and reduce costs.
Appendix "D" also permits proponents to demonstrate the safety of their technology through alternative means, so long as overall safety requirements are satisfied. Alternative approaches include applying industry codes and standards from other jurisdictions, using an approach from another industry that is not yet commonly applied to the nuclear sector, and using new technologies. This is particularly advantageous since many SMR designs implement innovative approaches to safety, which previously may not have been permitted.
The CNSC's revisions to REGDOC-3.5.3, Regulatory Fundamentals is a needed step towards a more performance-based regulatory scheme necessary for the expedient deployment and safe regulation of SMRs. It is important to note that regulatory documents such as REGDOC-3.5.3 are intended to provide regulator guidance to proponents, but do not represent any substantive rules for the CNSC's regulation of SMRs. It will be interesting to see how the CNSC employs Appendix "D" to SMRs in the future.
Footnotes
1. Risk informed decision making is an overarching organizing philosophy that implements a myriad of decision-making tools and risk assessment approaches. Cornerstones of the risk informed decision making process applied by the CNSC include risk assessment, conservative decision-making and the principle of proportionality. These cornerstones are not expressly prescribed by the CNSC, but are espoused by the regulatory concepts they employ, such as the precautionary principle, deterministic risk assessment, probabilistic risk assessment, and the graded approach.
2. The graded approach instructs that regulatory assessment is to be applied in accordance with the circumstances and the likelihood and possible consequences of, and the level of risk associated with, a loss of control. The goal of the graded approach is to ensure that fundamental safety objectives are satisfied in a risk-informed manner commensurate with the risk, complexity and novelty of the activity.
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