Generic Design Assessment (GDA) is a process carried out by the Office for Nuclear Regulation (ONR), the Environment Agency and Natural Resources Wales (NRW) to assess the safety, security, and environmental protection aspects of a nuclear power plant design that is intended to be deployed in Great Britain. The GDA process is a voluntary, non-mandatory process. Successful completion of the three-step GDA culminates in the issue of a Design Acceptance Confirmation (DAC) from the ONR and a Statement of Design Acceptability (SoDA) from the Environment Agency.

In May 2021, the UK’s Department for Business, Energy and Industrial Strategy opened the GDA process to advanced nuclear technologies, including small modular reactors (SMRs).

GE Hitachi Nuclear Energy (GEH) submitted a GDA entry application for its BWRX-300 SMR to the UK Department for Business, Energy and Industrial Strategy in December 2022. The BWRX-300 is a 300 MWe water-cooled, natural circulation SMR with passive safety systems that leverages the design and licensing basis of GEH’s ESBWR boiling water reactor. 

Step 1 of the GDA of GEH’s BWRX-300 began in January this year and focused on agreeing the scope and schedule for Step 2. This stage has now been successfully completed.

“Based on the evidence provided, the regulators are satisfied that GE-Hitachi has demonstrated its readiness to proceed to Step 2,” the regulators said in a joint statement. “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.”

Step 2 of the GDA process for the BWRX-300 is expected to be completed 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 DAC or SoDA will be issued at the end of the currently agreed programme of work.

GEH is receiving some of its funding for its own costs and those of the regulators for this GDA from the UK government’s Future Nuclear Enabling Fund programme. Separately, it has been selected by Great British Nuclear to advance to the next phase of the SMR competition to identify technologies to be included in the UK nuclear programme.

“Progressing to Step 2 of the GDA demonstrates our unwavering desire to deliver a fleet of nuclear reactors in the UK,” said GEH UK Country Leader Andy Champ. “Our design will be tried and tested through our partnership with Ontario Power Generation to deploy the first civil SMR in the G7. This means we have extensive experience across the full nuclear lifecycle, with a proven track record deploying reactor technology on time and on budget.”

Chris Southern, senior project director at GEH, added: “This significant milestone underscores GEH’s commitment to advancing SMR technology safely in the UK. Our BWRX-300 technology builds on our already proven BWR design, offering not only a smaller but simpler modular reactor, without sacrificing safety responses or operational performance. We remain dedicated to demonstrating the feasibility and reliability of our SMR technology as we progress through Great British Nuclear’s SMR competition.”

Generic Design Assessments have previously been completed for the EDF/Areva UK EPR, the Westinghouse AP1000, the Hitachi-GE UK ABWR and the CGN/EDF/GNI UK HPR1000 designs. A GDA assessment is currently ongoing for Rolls-Royce SMR Limited’s small modular reactor design, GE Hitachi Nuclear Energy’s BWRX-300 and Holtec International’s SMR-300. In August, Westinghouse’s AP300 was accepted for a GDA review. Earlier this month, Newcleo announced it had applied for approval a GDA assessment of its LFR-AS-200 small modular lead-cooled fast reactor.