GE-Hitachi’s Small Modular Reactor completes first step of design assessment

GDA process enables regulators to begin assessing the safety, security, safeguarding and environmental aspects of new nuclear power station designs at an early stage of the regulatory process.

GE-Hitachi Nuclear Energy International LLC's proposals for its BWRX-300 nuclear reactor have progressed to the next step of the design assessment process, the Environment Agency, Office for Nuclear Regulation (ONR) and Natural Resources Wales (NRW) announced today.

The Generic Design Assessment (GDA) process enables regulators to begin assessing the safety, security, safeguarding and environmental aspects of new nuclear power station designs at an early stage of the regulatory process and to provide confidence that these new designs can be constructed, operated, and decommissioned in England and Wales.

The focus of the regulators during Step 1, which started in January 2024, has been on ensuring the necessary arrangements, processes and submissions are in place to begin Step 2 of GDA, and that an agreed scope and schedule for the technical assessment of the GE-Hitachi BWRX-300 reactor design are in place. Based on the evidence provided, the regulators are satisfied that GE-Hitachi has demonstrated its readiness to proceed to Step 2.

During Step 2, regulatory activity will be targeted on assessing the fundamental adequacy of the BWRX-300 design for deployment in England and Wales. This will consider the suitability of the methodologies, approaches, codes, standards and philosophies identified by GE-Hitachi in the generic safety, security, safeguards and environment cases for securing future regulatory permissions and permits.

As the independent environmental regulator of nuclear sites and radioactive substances in England, the Environment Agency ensures that nuclear companies and the sites they operate meet high standards of environmental protection throughout the stages of design, construction, operation and decommissioning.

Saffron Price-Finnerty, the Environment Agency's New Reactors Programme Manager, said:

Our Environment Agency team has been working diligently with GE-Hitachi to achieve the first major milestone of the GDA of its BWRX-300 small modular reactor design and we're now ready to move from Step 1, Initiation, to Step 2, Fundamental Assessment.

During Step 2 our skilled and experienced team will be assessing the underpinning fundamentals of the BWRX-300, including identifying any specific environmental protection issues or concerns that we find.

I'm grateful for the hard work of our team and that of GE-Hitachi to meet this milestone. We welcome GE-Hitachi's initiative of taking a truly international approach in working towards a single design for global deployment. We'll work with other regulators to see what can be achieved while ensuring protection of people and the environment, and we encourage people to engage with the next steps through the public comments process.

Rob Exley, ONR's Head of Regulation for the GE-Hitachi BWRX-300 design, said:

Step 2 of the GDA will mark the beginning of ONR's technical assessment of the BWRX-300 reactor, where we'll examine GE-Hitachi's submissions setting out why it believes its generic design can be safely and securely deployed in Great Britain.

We will also seek to build upon our collaborative partnerships with both the US Nuclear Regulatory Commission and the Canadian Nuclear Safety Commission. We are fully supportive of GE-Hitachi's ambition to maintain a standard reactor design with minimal design changes from country to country. As all our organisations are reviewing essentially the same design in parallel, ONR is committed to exploring all opportunities for more efficient regulation, the sharing of insights and information, considering common submissions and analysis, and enabling GE-Hitachi to maintain a common design as much as possible.

Natural Resources Wales participates in GDA where the company designing the nuclear power station advises that its design might be proposed for construction in Wales.

Paul Gibson, Natural Resources Wales' Radioactivity & Industry Policy Team Leader said:

As the project progresses to Step 2 (Fundamental Assessment), we will continue working closely with our regulatory partners, the Environment Agency and Office for Nuclear Regulation, on the GDA of the GE-Hitachi BWRX-300.

GE-Hitachi has launched a new GDA website where it publishes detailed information about its design and a public comments process. The public comments process enables anyone to submit comments and questions about the reactor design to the company for its response. Regulators see the questions and the responses, and, where relevant, use these to help inform their assessments throughout the rest of the GDA process.

GE-Hitachi Nuclear Energy is receiving some of its funding for its own costs and those of the regulators for this GDA from government's Future Nuclear Enabling Fund programme. Separately, they have been selected by Great British Nuclear to advance to the next phase of the small modular reactor competition to identify technologies to be included in the UK nuclear programme.

GE-Hitachi applied for a two-step GDA which is expected to complete in December 2025. At the end of Step 2, the regulators will publish Step 2 GDA Statements indicating their level of confidence in whether the design can potentially be built, operated, and decommissioned in England and Wales in a way that is safe, secure and protects the environment.

No Design Acceptance Confirmation (DAC) or Statement of Design Acceptability (SoDA) will be issued at the end of the currently agreed programme of work.

If GE-Hitachi's BWRX-300 is proposed for construction in England or Wales, then a further period of detailed design assessment would need to be carried out by the regulators. This would be required before safety significant construction could commence and environmental permitting could be completed. This could be carried out on a generic basis with GE-Hitachi if it chooses to return to GDA to complete Step 3, or with the licensee or operator of a site-specific development.

For more information, please read ONR's end of Step 1 statement and the Environment Agency and Natural Resources Wales (NRW) joint end of Step 1 statement.