GE Vernova Hitachi’s BWRX-300 completes Generic Design Assessment
Source: gov.uk (2025-12-11)

GDA process enables regulators to assess 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 Environment Agency, Office for Nuclear Regulation (ONR) and Natural Resources Wales (NRW) are pleased to announce that the GE Vernova Hitachi BWRX-300 nuclear reactor design has successfully completed Step 2 of the Generic Design Assessment (GDA).

The two-step GDA began in January 2024 with a year-long initiation phase, during which regulators worked closely with GE Vernova Hitachi to establish a robust foundation for the assessment process.

Step 2, which began in December 2024, has seen regulators complete a comprehensive and rigorous assessment of the BWRX-300 reactor design. This phase has focused on evaluating the fundamental adequacy of the design and its safety, security, safeguards and environmental protection documentation.

The planned programme of assessment activities has now concluded with the issue of two GDA statements that set out our regulatory conclusions on the BWRX-300 design and its supporting documentation. Regulators have confirmed that their assessment has identified no fundamental safety, security, safeguards or environmental protection shortfalls with the design that could prevent its deployment in England and Wales.

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

The accelerated pace of this first two-Step GDA was enabled by the delivery of a complete set of documentation by GE Vernova Hitachi at the start of Step 2. This helped our assessment team to plan their work effectively and efficiently.

Their assessments were targeted and proportionate in ensuring that there were no fundamental shortfalls in environmental protection. It has been a considerable effort from both the Requesting Party and regulators, resulting in a quality outcome in such a short timeframe.

As the 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.

Rob Exley, ONR’s Head of the BWRX-300 GDA, said:

GE Vernova Hitachi opted for a shorter two-step GDA, making it the first requesting party to take advantage of the flexibility we introduced in our modernised GDA process.

This means it is the quickest GDA engagement completed to date, facilitated by GE Vernova Hitachi’s responsiveness, the quality and maturity of its submissions, learning from previous GDAs, and our active collaboration with regulatory colleagues in the US and Canada who have been evaluating the BWRX-300 in parallel to our assessment.

Paul Gibson, Natural Resources Wales Nuclear Team Leader, said:

Throughout Step 2 we have worked closely with the Environment Agency and Office for Nuclear Regulation towards the fundamental assessment of the GE Vernova Hitachi SMR, resulting in the successful delivery of this first two-step GDA.

Currently, there are no plans to deploy the GE Vernova Hitachi BWRX-300 design in England and Wales, and no sites have been identified for its deployment.

Should an organisation wish to progress plans to deploy the BWRX-300 design, the regulators would need to undertake a further period of detailed design assessment before safety-significant construction could begin and environmental permits could be issued.

This assessment could be conducted on a generic basis with GE Vernova Hitachi, should the company choose to return to the GDA process to complete Step 3. Alternatively, it could be undertaken with a licensee or constructor as part of a site-specific development in Great Britain

The GDA process (https://www.gov.uk/guidance/new-nuclear-power-stations-assessing-reactor-designs) enables regulators to assesss 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.

Read the reports:
- GDA Step 2 of the GE Vernova Hitachi SMR: fundamental assessment - GOV.UK (https://www.gov.uk/government/publications/gda-step-2-of-the-ge-vernova-hitachi-smr-fundamental-assessment)
Notes to editors:
- The voluntary Generic Design Assessment (GDA) process is used by the nuclear regulators to assess new nuclear power station designs. It allows the regulators to assess the safety, security and environmental implications of new reactor designs, separately from applications to build them at specific sites.
Requesting parties can opt to either complete a two-step or three-step GDA.
- ONR and the EA have each issued GE Vernova Hitachi with a GDA statement. The statement provides an indication of our confidence in the design, based upon the assessment conducted to date, and our judgement on whether the design is potentially capable of being built and operated on a site bounded by the generic site envelope, in a way that is acceptably safe and secure and properly protects the environment. It also identifies any matters which might be in conflict with UK government policy.