New nuclear power: assessing power station designs

Documents explaining why and how regulators are assessing designs of new nuclear power stations and how to get involved.


About generic design assessment (GDA)

The government has outlined its commitment to new nuclear developments in the UK. Its energy policy states that nuclear power, together with gas and renewable energy such as wind and solar power, will help meet the country’s energy needs in the future. It will also meet its commitment to reduce carbon emissions.

As regulators of the nuclear industry, the Office for Nuclear Regulation (ONR), the Environment Agency and Natural Resources Wales (NRW), are working together to ensure that any new nuclear power stations built in the UK meet high standards of safety, security, environmental protection and waste management.

The ONR and the Environment Agency have developed an assessment process called ‘GDA, which enables them to scrutinise new nuclear power station designs before they are built. It means they can identify any potential design or technical issues early and ask the reactor designer to address them.

At the end of the GDA process the regulators issue reports on their findings along with the supporting technical assessment reports. If the reactor design is judged to be acceptable then ONR would issue a ‘design acceptance confirmation’ (DAC) and the Environment Agency and NRW would issue a ‘statement of design acceptability’ (SoDA).

A DAC or SoDA confirms the regulators consider a power station based on the design could be built and operated at a site in the UK. But before that could happen the site operator would need to apply for and obtain site specific environmental, safety, security, planning and other approvals. When making decisions about site specific permit applications the regulators will take account of all the work done during GDA.

The GDA process is open and transparent and there are a number of ways to get involved.

The comments process

Any nuclear power station design company going through GDA is required to set up a website, publish information about the design and invite comments and questions about it. You can make a comment or ask a question and the design company will respond to you.


The Environment Agency in England and NRW in Wales will consult on their preliminary findings from detailed assessment during the GDA process.

Public dialogue

The nuclear regulators worked with Sciencewise to understand how the public want to be engaged and consulted about assessment of new nuclear power station designs.

Meetings and events

You can talk to the Environment Agency at Site Stakeholder Groups, Local Community Liaison Councils and public events.

Generic design assessment: General Nuclear System Ltd’s UK HPR1000

Government requested that the regulators begin assessments of General Nuclear System Ltd’s UK HPR1000. Regulators began preparatory step 1 in January 2017 and started step 2 in November 2017.

Bradwell B Power Generation Company Ltd is proposing to construct this design at its site at Bradwell in Essex.

The comments process opened in November 2017. It continues throughout this GDA until around 4 months before the regulators make their decisions on the acceptability of the UK HPR1000.

You can make a comment or ask a question about this design on General Nuclear System’s website.

You can also send comments by email to the Joint Programme Office -

Read more information about the assessment on the joint regulators’ website.

More information

Infographics to explain nuclear regulation

Advice note for flood and coastal erosion risk management

Generic design assessment: EDF/Areva’s UK EPR™

In December 2012 the regulators completed their GDA of EDF/Areva’s UK EPR™ nuclear power station design that EDF Energy plan to build at Hinkley Point and Sizewell. They concluded that the design would be acceptable if built in the UK.

Generic design assessment: Hitachi-GE’s UK ABWR

Regulators began assessments of Hitachi-GE’s UK Advanced Boiling Water Reactor (ABWR) design in January 2014. Horizon Nuclear Power propose to construct UK ABWRs at Wylfa and Oldbury. Other developers could similarly propose to build a new nuclear power station based on the UK ABWR design at another UK site.

The GDA public comments process opened in January 2014 and closed in August 2017.

In December 2017 the regulators completed their GDA of Hitachi-GE’s UK ABWR nuclear power station design. They concluded that the design would be acceptable if built in the UK.

Read information about this design on the Hitachi-GE website.

Generic design assessment: Westinghouse Electric Company's AP1000®

In March 2017 the regulators completed their GDA of Westinghouse Electric Company’s AP1000® nuclear power station design that NuGEN propose to build at Moorside, Cumbria. They concluded that the design would be acceptable if built in the UK.

Published 3 October 2014
Last updated 14 December 2017 + show all updates
  1. The Environment Agency, Natural Resources Wales and the Office for Nuclear Regulation have completed their Generic Design Assessment of Hitachi-GE’s UK Advanced Boiling Water Reactor nuclear power station. We've published the summary decision document, decision document and statement of design acceptability.
  2. We've launched the next step in the assessment of the Chinese nuclear reactor design.
  3. Link to new document: Advice note for flood and coastal erosion risk management.
  4. New infographics to explain and enable understanding of nuclear regulation.
  5. New publication. GDA decisions: AP1000 nuclear power station design by Westinghouse Electric Company.
  6. Link added to new consultation plan: GDA of Hitachi-GE Nuclear Energy Ltd’s UK Advanced Boiling Water Reactor.
  7. Link to new report - Discharges from boiling water reactors: a review of available discharge data.
  8. New document added - New nuclear power stations: about generic design assessment
  9. First published.