The Office for Nuclear Regulation (ONR), alongside The Environment Agency, has completed a first-of-its-kind Preliminary Design Review on topics relating to Last Energy's PWR-20 Nuclear Reactor Design and Last Energy UK’s organisational plans.
This regulatory review, which ran between February 2025 and June 2025, was conducted under the early engagement framework for new nuclear projects.
The review examined three areas chosen by Last Energy: organisational plans and arrangements, environment and decommissioning, and safety analysis processes and maturity.
Through applicant submissions, the Preliminary Design Review process aims to support regulators to identify potentially significant gaps against regulatory expectations and offers guidance on how to resolve them.
It also helps applicants achieve a better understanding of the project risks on the pathways through GDA or, as Last Energy are progressing, through site-specific design assessment, providing them with an early opportunity to develop credible plans for resolution.
Diego Lisbona, ONR’s Head of Regulation – Advanced Nuclear Technologies, said: “Our assessment involved multiple technical workshops and during the review Last Energy progressed its organisational plans and committed to address regulatory feedback on disposal routes and safety analysis, to cite examples across the areas submitted.
“The early engagement process shows the flexibility of the UK regulatory framework. The feedback from companies is that they value the approach we take.
“We are asked questions on a wide range of topics and early engagement is our platform to give tailored answers to their individual needs.”
The Preliminary Design Review has built initial confidence that Last Energy understands regulatory expectations in those three areas and is planning to address them as the PWR-20 design matures and is subject to site-specific design assessment for deployment at their identified South Wales site.
However, the review is not a substitute for generic or site-specific design assessment, nuclear site licencing, or environmental permitting processes.