Our role in nuclear regulation

Existing Nuclear Licensed Sites

We are responsible for issuing environmental permissions to operators of existing nuclear sites in Wales and regulating the operator’s compliance against the conditions within the permits.

There are currently three nuclear sites in Wales; two sites in North Wales, at Trawsfynydd and Wylfa, which historically produced electricity from nuclear power. These are operated by Magnox plc and we regulate their compliance against the environmental permits that we issued to them.

There is also a nuclear site in Cardiff that historically manufactured radio-chemicals. This is operated by GE Healthcare. Similarly we regulate their compliance against an environmental permit which we issued to them. Our work includes site inspections, environmental monitoring, audits and liaison with local communities and stakeholders.

Our environmental regulation of nuclear sites covers the full ‘life-cycle’ of the site from construction, operation and decommissioning to final clean-up of the site in close partnership with our partners for nuclear safety and security (The Office for Nuclear Regulation).

New Nuclear Sites

We are also responsible for the environmental permissions relating to the construction and operation of any new nuclear sites in Wales, including new nuclear power stations and the relevant 'associated developments' such as workers accommodation and ‘park and ride’ facilities.

Currently there is a proposal to build a new nuclear power station in Wales. This is called Wylfa Newydd and the developer (Horizon Nuclear Power (HNP), is proposing to locate it adjacent to the existing Magnox site (Wylfa A) on the Isle of Anglesey. HNP are proposing to build a new nuclear power station to produce electricity using two Advanced Boiling Water Reactors (ABWRs) designed by Hitachi GE Ltd.

Together with our partners, we are currently involved in an extensive process assessing the proposed nuclear reactor design and also detailed pre-application discussions with the developer (HNP) regarding the environmental permissions that would be required.

Environmental permitting

Any company that wishes to construct and operate a new nuclear power station in Wales will need to apply to us for a range of environmental permissions that may include permits, licences and consents.

We will give advice and guidance to the developer before they apply for these permissions. Once they are submitted to us, we will conduct a detailed assessment programme and decide if the permissions should be issued and what specific conditions should be applied.


We will provide pre-planning advice and guidance to developers and will be statutory consultees to the relevant planning authority; for example to the Local Authority and Planning Inspectorate.

Other work related to new nuclear power in Wales

Our work around the environmental regulation of new nuclear sites in Wales includes:

  • providing information about the environment around potential sites so developers can make sound decisions to protect and enhance our natural habitat
  • undertake environmental monitoring and publish the results in the annual ‘Radioactivity in food and the environment (RIFE) report’
  • advising on the scope of developers’ Environmental Impact Assessments and providing information for the assessments
  • regulating site investigation works that are needed to check sites are suitable for development
  • providing pre-application advice
  • responding to consultations run by government, developers and local authorities
  • advising on flood and coastal risk matters for development sites, including 'associated developments' away from the main power station site, for example workers’ accommodation
  • providing advice and information to the planning inspectorate about planning and our regulatory matters
  • regulating the sites for environmental matters during their construction, operation and decommissioning phase

Generic Design Assessment (GDA)

Generic Design Assessment is the process being used by the nuclear regulators (Office Nuclear Regulation, the Environment Agency and Natural Resources Wales) to assess any new nuclear power station designs. It allows the regulators to assess the safety, security and environmental implications of new rector designs, separately from applications to build them at specific sites. In January 2014 the regulators began assessing Hitachi-GE's UK Advanced Boiling Water Reactor design (UK ABWR).

The GDA process is not site specific but rather generic and has a number of steps, with the assessment getting increasingly detailed through the four year process as the regulators technically assess and scrutinise the design from a safety, security and environmental perspective. In December 2017, the Generic Design Assessment (GDA) programme for the UK ABWR design was completed. The three regulators – NRW, Environment Agency and Office of Nuclear Regulation published their decision and are satisfied that this reactor design meets our regulatory expectations on safety, security and environmental protection.

As the developer (Horizon Nuclear Power) for Wylfa Newydd is planning to use the UK ABWR reactor design for the proposed site on Anglesey, we will use information gained from the GDA process in the assessment of any future environmental permissions applications for this site. We will now work on the detailed assessments of the permits, licences and consents that Horizon Nuclear Power will need to have in place to build Wylfa Newydd.

Read an update on this consultation process 

As the developer for Wylfa Newydd is planning to use the ABWR reactor design, we will use information from the GDA process in the assessment of any future environmental permissions applications for Wylfa Newydd.

Communication with stakeholders and local people

During both the Generic Assessment of the nuclear reactor design and any site specific programme, we will consult with stakeholders and the public on our work. We will publish an engagement plan to inform people of how we will communicate and consult with them.

Geological Disposal Facility (GDF)

The Welsh Government has adopted a policy of supporting geological disposal for the long-term management of higher activity radioactive waste (HAW). This is in line with the UK Government’s overarching approach for managing higher activity radioactive waste in England, Wales and Northern Ireland through geological disposal.

Following a public consultation that ended in 2018, the Welsh Government has launched a policy that outlines the engagement process for communities in Wales who wish to enter into discussions to explore potentially hosting a geological disposal facility (GDF). This follows a similar process launched by the UK Government in December 2018, for communities in England.

The UK Government funded programme to deliver a single GDF for the high activity waste produced in Wales, England and Northern Ireland, will be delivered by Radioactive Waste Management Ltd (RWM), a subsidiary of the Nuclear Decommissioning Authority. RWM is responsible for implementing geological disposal and they will lead the siting process, working in partnership with communities to identify a suitable location to host a geological disposal facility.

If a site for a GDF was identified in Wales, planning permission would be needed as well as site specific safety and security permits from the Office for Nuclear Regulation (ONR) and the relevant environmental permits from NRW.  As with the nuclear sites currently in Wales, we would work closely with the ONR to jointly regulate a GDF. If a site were identified in England, these roles would be undertaken by The Environment Agency and ONR.

Our responsibility would be making sure that the developer and operator of a GDF in Wales meets the high standards we require to protect people and the environment, both now and for future generations. We do not have a role in the decision to select a GDF site.  We will be available to provide information and advice to communities on our role in environmental protection throughout the site evaluation process.

Other work related to nuclear regulation in the UK

As well as the work we carry out for the environmental regulation of specific nuclear sites in Wales, as a nuclear regulator we work extensively with our partners in England, Scotland and Northern Ireland for the detailed work-streams across the whole nuclear sector in the UK.

This includes working with designers, operators, developers, regulatory partners and Government Departments (UK and Welsh Government) across a multitude of policy, strategy and legislative frameworks. This includes planning for and determining changes to UK and European legislation and how that might affect the regulation of the nuclear sector in Wales. Subjects include work related to the current and future strategies for the storage and disposal of radioactive wastes in the UK, the future use of nuclear energy and nuclear medicine, nuclear research and development and other key aspects of the nuclear sector that needs to be considered and regulated for.

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