GovWire

The Environment Agency, Office for Nuclear Regulation (ONR) and Natural Resources Wales are working together to make sure that any new nuclear power stations built in the UK meet high standards for:

• safety
• security
• environmental protection
• waste management
• nuclear safeguards

Generic Design Assessment

Government has stated that nuclear power plays an important role as part of a mix of different energy sources. In 2007 the UK government asked the regulators to work together to introduce a new process for assessing designs for new nuclear power stations.

The Environment Agency and ONR developed a process called Generic Design Assessment (GDA). They use this process to scrutinise new nuclear power stations at an early stage. This is before a developer has formed detailed proposals for building at a specific site or applied for licences or permits. This means that the regulators can identify potential design or technical concerns early on and ask the designer to resolve them.

The process has up to 3 steps, with the assessment becoming increasingly more detailed. If the design company still has significant issues to resolve after the regulators have completed their planned assessments, further steps can be added to the process.

It takes around 4 years to complete the 3 steps of the GDA process.

1. Initiation

2. Fundamental assessment

3. Detailed assessment

The design company must provide detailed information to make the environment case for their nuclear power station design. The regulators will carefully examine the information and will ask questions. They will request further information if necessary and identify if changes to the design might be needed.

At the end of each step, the regulators issue statements and reports about their findings. What they issue will depend on the scope of the GDA they agreed with the design company during step 1.

If the agreed scope is sufficiently broad and detailed, with the potential to achieve a Statement of Design Acceptability (SoDA), then we will consider issuing one. We will only issue a SoDA if we judge that the design is acceptable. Similarly ONR will consider issuing a Design Acceptance Confirmation (DAC).

Issuing a SoDA and DAC means that the regulators consider that if a new nuclear power station were built using that design, it should be capable of meeting the UKs high standards of safety, security and environmental protection.

Before a site operator can build a new nuclear power station, they must apply for and obtain all of the site specific approvals they need. These include:

• environmental permits for construction and operation
• a development consent order (planning permission) from the Secretary of State for Energy Security and Net Zero
• a nuclear site licence and other safety and security consents from ONR

When making decisions about an operators environmental permit applications for a proposed site, the Environment Agency will take account of all the work it has done during GDA.

More information about GDA

The regulators have produced some infographics about GDA.

Modernised GDA process and updated guidance

In 2019 the regulators modernised the GDA process, using their learning from previous assessments. They have made the process more flexible to help with the assessment of small modular reactors and less mature designs. This includes providing other options for other GDA outcomes, in addition to the current option of issuing (or not) a DAC and SoDA.

The Environment Agency has produced updated guidance for organisations who want to submit a design for assessment. We refer to these organisations as requesting parties because they can be made up of a number of companies, including nuclear power station designers and operators. The guidance explains the GDA process and the information they must provide.

In developing the modernised GDA process the regulators have been careful to make sure that a requesting party still has to meet the same requirements and expectations to achieve a SoDA and DAC.

GDAs started before 2019 followed earlier versions of the assessment of candidate nuclear power plant designs produced by the Environment Agency and ONR.

The regulators will be using the updated guidance for all future GDAs.

During 2024, the regulators published new joint guidance for developers and designers of new nuclear power stations seeking early engagement before entering generic design assessment and permitting. The process enables applicants to develop their understanding of regulatory pathways and requirements.

Public and stakeholder engagement

GDA is an open and transparent process. The nuclear regulators worked with Sciencewise to understand how the public wants to be informed and consulted about assessing new nuclear power station designs.

The nuclear regulators also worked with partners and Sciencewise to explore public views toward the siting and deployment of advanced nuclear technologies, to support policy development and inform future engagement.

There are a number of ways the public and other stakeholders can get involved in GDA.

GDA comments process

A nuclear power station design company going through GDA must set up a website to:

• publish information about the design
• invite the public to ask questions and make comments

The design company must respond to any comments or questions they receive.

The regulators will see the comments and questions and the responses provided. They can also use this information to help inform their assessment work.

The Environment Agency and ONR have set up a joint programme office to help administer the 