Office for Nuclear Regulation, Environment Agency & Natural Resources Wales

Generic Design Assessment (GDA) of new nuclear power stations

These web pages have been produced by the Office for Nuclear Regulation (ONR), Environment Agency and Natural Resources Wales (NRW). These regulators are working together to ensure any new nuclear power stations built in Great Britain meet high standards of safety, security, environmental protection and waste management, through a process called Generic Design Assessment (GDA).

Before a new nuclear power station can be built and operated in Great Britain, in addition to the reactor design going through the GDA process, the proposed operator must obtain permission from regulators and government in the form of:

 We have designed these pages so they are accessible to anyone with an interest in the GDA process, including the general public and other regulators. They also contain technical information for organisations submitting designs for GDA, which can be found in the "Assessment of reactors" section.

Latest news

GE Hitachi BWRX-300 - 25 January 2024

The Department for Energy Security and Net Zero (DESNZ) asked ONR, the Environment Agency and Natural Resources Wales to begin a two-step Generic Design Assessment (GDA) for GE Hitachi’s BWRX-300 reactor.

Step 1 of the GDA will focus on agreeing the scope and schedule for step 2. The GDA assessment will look to actively explore opportunities to maximise the value of international regulatory collaboration and identify efficiencies in processes.

Regulators begin Holtec reactor assessment - 7 December, 2023

The Office for Nuclear Regulation, along with the Environment Agency and Natural Resources Wales, has started a Generic Design Assessment (GDA) for Holtec International’s 300 MWe Pressurised Water Reactor.

The Department for Energy Security and Net Zero made the request to the regulators following its readiness review of the Holtec International application.

GDA comments process

You can make a comment about a design via the reactor designer’s website. The reactor designer will respond to the comments and issues raised.

The comments process