Environment Agency
The Sizewell nuclear power stations are in Suffolk, England on the North Sea coast.
Sizewell A was Sizewells first nuclear power station. It operated from 1966 to 2006 and is being decommissioned.
Sizewell B is a Pressurised Water Reactor, the first to be constructed in the UK. It will stop generating electricity in 2035.
Sizewell C Company (SZC Co.), EDFs new nuclear build company has been granted development consent to build a twin reactor nuclear power station at the site.
Environment Agencys regulation at Sizewell
The Environment Agency is the independent environmental regulator for the nuclear industry in England. We make sure that nuclear power stations meet our high standards of environmental protection.
We regulate the Sizewell sites, working closely with the Office for Nuclear Regulation (ONR).
We have published information:
- on how we regulate nuclear sites like Hinkley Point
- explaining how levels of radioactivity in the environment around the Sizewell sites are monitored and assessed
Sizewell A
Sizewell A is being decommissioned. The Environment Agency regulates how Magnox manage and dispose of radioactive waste from decommissioning at the site.
Environment Agency nuclear regulators attend and report to the Sizewell site stakeholder group for Sizewell A.
You can find and request information about the environmental permits for Sizewell A on the public register. You need to search under Magnox.
You can find out more about the decommissioning of Sizewell A from:
Sizewell B
The Environment Agency regulates how EDF operates the power station at Sizewell B. In particular, we regulate discharges from the site and radioactive waste disposal.
Environment Agency nuclear regulators attend and report to the Sizewell site stakeholder group for Sizewell B.
You can find and request information about the environmental permits for Sizewell B on the public register. You need to search under EDF.
The Environment Agency issued a permit variation on 1 September 2021. The decision follows a consultation on an application from EDF Sizewell B company (EDF Energy Nuclear Generation Ltd) to increase the limit for Carbon-14 discharges to air.
You can:
- review the decision and changes to the permit on Citizen Space
- access the reports about Sizewell B from ONR
- read about the power station from EDF
Sizewell C
Power station design for Sizewell C
The Environment Agency and ONR developed an assessment process called Generic Design Assessment (GDA). We use this to scrutinise new nuclear power station designs before they are built.
We used the GDA process to assess the Areva UK EPR reactor design that will be built at the Sizewell C site. The assessment process ended in December 2012 and the Environment Agency and ONR concluded that the reactor design is acceptable. This means that people and the environment will be properly protected if this reactor design is constructed and operated in the UK.
You can read reports about the GDA assessment process for this design.
The Environment Agency will use information from our GDA process assessments to help inform decisions on SZC Cos environmental permit applications for Sizewell C.
Environmental permits for Sizewell C
SZC Co applied for permits from the Environment Agency to build and operate Sizewell C in June 2020. They applied for the permits under the name of NNB Generation Company (SZC) Ltd. These are permits are to:
- dispose of and discharge radioactive wastes
- operate standby power supply systems using diesel generators
- discharge cooling water and liquid effluents into the North Sea
The Environment Agency consulted on:
- the applications from 6 July to 2 October 2020
- its proposed decisions and draft permits from 4 July to 25 September 2022.
The Environment Agency published their decision in March 2023.
The Environment Agency has carried out a Habitats Regulation Assessment (HRA) for these permits. The HRA checks whether the activity could have a significant negative effect on protected species such as migratory fish or birds, or on protected areas nearby.
The Environment Agency must make sure that activities carried out under an environmental permit will not have a negative effect on vulnerable species and habitats or contribute to their loss.
SZC Co must also apply to the Environment Agency for environmental permits that will allow it to carry out:
- site preparation
- construction works
- associated developments such as a park and ride
The Environment Agency will continue to receive applications for environmental permits as the development of Sizewell C progresses.
Environment Agency staff attend and present information to Sizewell Cs community forum.
You can read information from the company about Sizewell C.
Licensing the Sizewell C nuclear site
ONR is responsible for licensing proposed new sites for nuclear power stations. On 30 June 2020 ONR received an application from NNB Generation Company (SZC) Ltd for a nuclear site licence for its site at Sizewell in Suffolk. It issued a progress statement in July 2022.
You can read information about ONRs regulation of Sizewell C.
Planning process for Sizewell C
SZC Co consulted on its pre-application proposals in stages. This part of the planning process led to the company making an application to the Planning Inspectorate for a Development Consent Order (DCO) for the site.
The consultation documents are published on the Sizewell C consultations website.
SZC Co completed four stages of consultation. Responses informed the development of its plans and its DCO application. Read the Environmen