Viewpoint: Collaboration - the key to streamlining nuclear regulation

13 January 2022

The application and interpretation of the same safety objectives into specific national regulatory requirements and guidance result in significant differences between the same reactor design when deployed in different countries, writes Claude Mayoral. A more harmonised approach to regulation will be needed to enable the widespread deployment of small modular and advanced reactor designs.

Claude Mayoral

Having spent many years working across the design and licensing of multiple EPR reactors in China, France, Finland and the UK, I have first-hand experience of the design changes and challenges involved in licensing a reactor design in different countries. It was this experience, and the delays that came with it, that forced me to ask the question - why are these changes necessary and do they improve safety?

It was this question that led me to gather several examples from different EPR projects and discuss these challenges with colleagues in World Nuclear Association’s Cooperation in Reactor Design Evaluation and Licensing (CORDEL) Working Group's Licensing and Permitting Task Force (LPTF). Through these discussions it became obvious that these challenges were not unique to the EPR, but licensing activities for the AP1000, ABWR and VVER across national boundaries had experienced similar challenges.

It became evident through these discussions that despite the harmonisation of high-level requirements, described by the International Atomic Energy Agency (IAEA), and the significant time and effort undertaken by reactor vendors to assess known differences between national regulatory requirements, and make upfront design changes prior to engaging the national regulators, lengthy exchanges with these regulators were still required that often led to further significant design changes.

Following a similar experience over several projects, I proposed to identify areas that are difficult for reactor vendors and future licensees to anticipate challenges that originate in different interpretations of safety rules and requirements between different regulators. It was through this proposal and further discussions within the LPTF that the report on Different Interpretations of Regulatory Requirements was developed.

Report findings

Nuclear safety objectives have been well-harmonised between countries and national regulators through cooperation at an international level resulting in safety standards and guides developed by the IAEA with the consensus of its Member States.

Nevertheless, despite the same safety objectives demonstrably being achieved in countries around the world, the application and interpretation of these objectives into specific national regulatory requirements and guidance result in significant differences between the same reactor design when deployed in different countries.

The report highlights that changes that had to be implemented often derive from the fact that every country has its own technical history and background and that the same words do not necessarily mean the same thing when it comes to performing very precise and thorough safety assessments. These changes form part of the reasons behind why the industry has not achieved large scale deployment of GEN III and GEN III+ reactor designs as they turn what should be nth-of-a-kind (NOAK) projects into first-of-a-kind (FOAK) projects, incurring the associated risks and costs.

Further to this, differences in acceptance criteria and methods of demonstrating a safety case can vary widely among national regulators. When a reactor vendor wishes to license its design in a country with a different regulatory framework, the form of the regulations and guidance can lead to a complete reframing of the original safety case and ultimately a significant amount of effort from the reactor vendor to produce new documentation that was not required by other national regulators.

It is also of note that the report describes various scenarios in which interpretation of fundamental safety requirements have resulted in significant design changes in different countries - yet for the majority of these examples there is no discernible increase in overall safety. So, the question remains, is there a more harmonised approach that can be employed?

Previous efforts to harmonise the differences between national regulatory requirements through the activities of the Multinational Design Evaluation Programme, the Western European Nuclear Regulators Association and CORDEL, among others, have not gone far enough and significant variations between national regulatory requirements remain.

The next generation of small modular and advanced reactor designs are already undergoing early licensing activities. They promise many improvements in performance and safety, and provide opportunities to open new markets to support deep decarbonisation of electrical grids and other industries.

However, to deliver on these promises, wide-scale deployment will be necessary, and I do not believe this is possible without the streamlining of national approaches to regulation - reactor vendors and supply chain must be able to deliver consistent products around the world. If this is not the case, many of these new reactor designs may never reach market.

What happens next?

The report provides detailed recommendations for governments, regulators and the nuclear industry to learn the lessons from the regulatory approach applied to previous reactor generations, that would support wider deployment of emerging technologies to improve the standardisation of reactor designs and to achieve harmonisation of regulatory approaches.

If we are to support wide-scale deployment of the next generation of reactor designs, I believe that it is critical that these stakeholders come together to increase collaborative efforts at an international level to develop an approach and framework that can be applied to future regulatory review efforts. It is only through a dedicated and concerted international effort that we will see real progress on the path to streamlining of regulatory approaches.

Great steps have already been taken on this path through ventures such as the joint reviews that are being conducted under the Memorandum of Cooperation between the Canadian Nuclear Safety Commission and the US Nuclear Regulatory Commission, the outputs from which identify similar areas to that discussed in the Different Interpretations of Regulatory Requirements report. I believe that this provides the foundation on which to launch a new framework entirely dedicated to driving the streamlining of regulatory approaches.

One such framework has been previously proposed by World Nuclear Association’s CORDEL report on Harmonisation of Reactor Design Evaluation and Licensing: Lessons Learned from Transport. Through such a framework, regulators could develop consistent risk-informed decision making processes, undertake joint assessments, validate other regulatory assessments where appropriate, develop bounding envelopes for assessment outputs and/or develop equivalence methodologies for the safety requirements.

As an industry we have demonstrated our willingness and ability to learn lessons from the past. I believe that it is now critical that we learn these lessons in relation to our approach to regulation and bring industry, regulators and governments closer together to investigate how we can streamline the regulatory process. CORDEL is looking at how to address this challenge. However, we cannot do this in isolation, and we need to work together to solve this imminent challenge that will allow the industry to move into new markets, support newcomer countries, and decarbonise many industrial sectors globally.

Claude Mayoral (Edvance), Chair of World Nuclear Association's CORDEL Licensing and Permitting Task Force