Wedoany.com Report-Apr. 19, The UK Office for Nuclear Regulation (ONR) has released its first report on international collaboration for regulating small modular reactors (SMRs). The document outlines efforts to work with global counterparts to streamline reactor design assessments while ensuring safety standards. The ONR’s initiatives focus on creating efficient, harmonized regulatory processes for SMRs, with activities spanning October 2024 to March 2025.

A two-unit plant based on Holtec's SMR-300, which is progressing through the UK's GDA process

A key milestone highlighted is the March 2024 trilateral memorandum of cooperation signed with the US Nuclear Regulatory Commission (NRC) and the Canadian Nuclear Safety Commission (CNSC). This agreement establishes a framework for collaboration, allowing each nation to maintain independent regulatory oversight while sharing expertise. The ONR also plays a leading role in global harmonization, serving as vice-chair of the International Atomic Energy Agency’s SMR Regulators’ Forum and chairing the OECD Nuclear Energy Agency’s Working Group on New Technologies.

The report details progress on three Generic Design Assessments (GDAs) in the UK: Rolls-Royce SMR, now in Step 3, and GE-Hitachi BWRX-300 and Holtec SMR-300, both in Step 2. The ONR has invited regulators from Poland, Sweden, the Netherlands, and the Czech Republic to observe the Rolls-Royce SMR assessment, fostering transparency and shared learning. Additional projects are under consideration for future assessments.

Tim Parkes, ONR’s Head of Regulation - GDA, said: “Our international collaboration is delivering tangible efficiency improvements to our assessment of new reactor designs and to harmonising regulatory approaches to SMRs and AMRs. This collaboration will support the global deployment of standard designs and help to ensure the highest safety standards are maintained.”

The ONR has engaged in technical workshops, high-level meetings with regulators and industry, and international forums to advance its goals. Upcoming plans include joint workshops with the NRC and CNSC on advanced construction methods, discussions on emerging reactor designs, and supporting UK trade delegations, including bilateral forums with Hungary. The ONR will provide quarterly updates on its international efforts.

In a separate development in the US, Arizona, Florida, and Louisiana have joined a lawsuit initiated by Texas, Utah, and microreactor developer Last Energy Inc. in December 2024. SMR developers Deep Fission and Valar Atomics are also part of the case, which challenges the NRC’s application of a 1956 rule to SMRs and research reactors. The rule requires all reactors to obtain construction and operating licenses, regardless of size or risk. The plaintiffs argue this creates unnecessary complexity and costs. The NRC notes it is addressing these concerns through a 2023 rulemaking process to develop a flexible, risk-informed regulatory framework for advanced reactors.