Holtec International’s Small Modular Reactor completes first step of design assessment

The Office for Nuclear Regulation (ONR), the Environment Agency and Natural Resources Wales (NRW) have today announced that they are progressing to the next phase of their assessment of Holtec International’s Small Modular Reactor (SMR) design.

The Generic Design Assessment (GDA) process allows the regulators to begin assessing the safety, security, safeguards and environmental aspects of new reactor designs before site-specific proposals are brought forward.

Step 1 of the GDA began in October 2023 and focused on agreeing the scope and schedule for Step 2, and this stage has now been successfully completed.Today marks the start of the fundamental assessment of the design (Step 2) which is expected to last for 14 months.

Agreeing the scope of the GDA throughout Step 1 has been based on information supplied by Holtec to the regulators so they can undertake a meaningful assessment of the design.

Holtec has completed all the requirements for Step 1 from the regulators' guidance with good progress made in developing its organisation and arrangements to support GDA.

Holtec has now launched a comments process on its new website, which enables anyone to submit comments and questions about the reactor design to the company for its response.

Relevant issues raised during the comments process, and Holtec’s responses to these issues, will be used to help inform the regulators’ assessments throughout the rest of the GDA process.

Tim Parkes, ONR's Head of Safety Regulation for Advanced Nuclear Technologies and the Holtec SMR-300 GDA, said: "GDA is a vital part of ensuring new reactor designs meet the high standards of safety, security and environmental protection required in Great Britain.

“Together with the Environment Agency and Natural Resources Wales, we have seen Holtec demonstrate readiness to move into Step 2 of the assessment where we can begin the technical assessments of the reactor.

“Throughout Step 1 Holtec has been mobilising its delivery organisation to complete the GDA and we have been agreeing the scope for our assessment in Step 2.

“We have improved our understanding of the generic SMR-300 design which will enable us to conduct a meaningful assessment throughout Step 2.

“Safety and security will always be our overriding priority, but we are committed to regulating in a way that does not impede technological advancements unless it is fully justified that we do so.

“We will continue to engage with the US Nuclear Regulatory Commission about potential collaboration and information exchange on the review and assessment of the SMR-300 design.”

Saffron Price-Finnerty, the Environment Agency’s New Reactors Programme Manager said: “We’re assessing the environmental acceptability of a new Small Modular Reactor design from Holtec International based in the US, working with Holtec Britain which is managing the delivery of the GDA in the UK. Holtec Britain has worked hard to grow the company sufficiently to be able to effectively manage and deliver the project.

“During the next step, our team of specialist assessors will identify any issues or concerns we have with the design and will work with the company to make sure it understands our expectations to ensure the protection of communities and the environment.

“During Step 1 we’ve reviewed the company’s arrangements, plans and readiness for Step 2 and learnt more about the reactor design. In our Step 1 statement we’ve summarised what we have looked at and concluded that we can progress to Step 2 of GDA where we will begin our fundamental assessment. We have also agreed the GDA scope and we are satisfied that all of the main systems from an environmental and waste management perspective are included within the assessment scope.

“We’re committed to transparency and working with others. Public and stakeholder engagement is important to us. This is a 2-Step GDA which won’t include a public consultation, so it’s even more important for people to get involved in the comments process, which begins today. You can review the information on the company’s website and provide your comments which are viewed by the regulators.”

Natural Resources Wales is also involved in the GDA process where there is a possibility the reactor design could be deployed in Wales, and will be leading on engagement with stakeholders in Wales.

Paul Gibson, the Radioactivity & Industry Policy Team Leader from Natural Resources Wales, said: “We have been working closely with the Environment Agency and Office for Nuclear Regulation on the Generic Design Assessment for the Holtec International SMR-300.

“As we have now reached the end of Step 1, we will continue working closely with our partners as the project progresses to fundamental assessment of the design in Step 2.”

The GDA process focuses on the design of a generic nuclear power station and is not site-specific. It is a voluntary, non-mandatory process aimed at providing early confidence that a proposed reactor design is capable of being constructed, operated and decommissioned in accordance with the high standards of safety, security, environmental protection and waste management in Great Britain.

GDA is a flexible process with up to three steps. The assessment becomes increasingly detailed with each step.

A Design Acceptance Confirmation (DAC) or Statement of Design Acceptability (SoDA), from ONR and the environmental regulators respectively, is issued at the end of a three-step GDA when the design meets the high safety, security, safeguards, environmental protection and waste management standards expected by our regulatory frameworks.

As Holtec is undergoing a two-step GDA for its SMR-300 design, no DAC or SoDA will be issued and our assessment will stop at the end of Step 2. At the end of Step 2 the regulators will issue a GDA Statement, indicating their level of confidence in whether the SMR-300 design can potentially be built, operated and decommissioned in Great Britain in a manner that is safe and secure.

This GDA is the first that is planned to finish at the end of Step 2. Should the company wish to continue its plans to build a small modular reactor in England or Wales, a further period of detailed design assessment will be carried out by the regulators, either as part of a future Step 3 or as part 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.

You can also visit the Holtec SMR-300 website.