The UK needs new low-carbon electricity generation to meet our commitment to reduce net greenhouse gas emissions to zero by 2050.

As an interim target, the government is aiming to decarbonise electricity generation by 2035. As transport and heating also need to be decarbonised by moving from fossil fuels to electric power, total electricity demand is expected to double by 2050 – which means that the UK will potentially need to quadruple its low-carbon generation in less than three decades.

An array of independent analysis and modelling studies have concluded that net zero needs nuclear to provide reliable baseload power which can balance the variability of wind and other renewables, and reduce the total costs of decarbonising the energy mix.

In the 2022 Energy Security Strategy, the government set a target of 24 gigawatts of electricity (GWe) from nuclear power stations by 2050 – up to 25 per cent of the UK’s projected electricity demand.

Current fleet

The UK currently has five operational nuclear power plants, owned by EDF, with a total capacity of 5.9GWe. All are now reaching the end of their operational lives.

In recent years, the UK nuclear fleet has generated around a fifth of the UK’s electricity – around 65 terawatt-hours (TWh) a year – from eight reactors. Seven of these are advanced gas-cooled reactors (AGRs) built over the 1960s–80s, all of which are scheduled to retire this decade.

Three AGRs – Dungeness B, Hunterston B and Hinkley Point B – have already ceased generation. Hartlepool and Heysham 1 are due to cease production in 2024, and Heysham 2 and Torness in 2028. Decommissioning of the AGR fleet will be managed by Nuclear Restoration Services (formerly Magnox).

The other operational nuclear power station is Sizewell B, the UK’s only pressurised water reactor (PWR), with a generating capacity of 1.2GWe. Sizewell B began operations in 1995, and was scheduled to retire in 2035. EDF has announced plans to extend its life by at least 20 years, allowing it to contribute to the 2050 target.

For the latest information, see EDF’s page on its UK nuclear power stations.

New reactors & GDA

Four gigawatt-scale reactor designs have been formally approved for new build in the UK:

  • Framatome’s EPR (originally the Areva European Pressurised Reactor) is a generation III+ PWR, offering a range of safety, economic and operational improvements over previous designs, and an output of 1.6GWe. Two EPRs are now under construction at Hinkley Point C in Somerset. EPRs are also under development or operational in Finland, France and China.
  • Westinghouse’s AP1000 is also a Gen III+ PWR, with an output of 1.1GWe. AP1000s are under construction or operational at two sites in China and two in the US.
  • The 1.3GWe Hitachi-GE Advanced Boiling Water Reactor (ABWR) operates at lower pressures and temperatures than PWRs, and features a much larger pressure vessel. Four ABWRs are in operation in Japan.
  • The Chinese Hualong HPR1000 is a 1.17GWe PWR. Three reactors are operational in China and two in Pakistan, with another 11 under construction in China.

These four reactors have all completed the UK’s generic design assessment (GDA) by the Office for Nuclear Regulation (ONR) and Environment Agency. This assessment is intended to support the construction of a number of new nuclear power stations by approving a standard reactor design which can be built in different locations by different developers. Each build will still require a site-specific licence.

The UK is also considering the development of small modular reactors based on Gen III+ technologies, as well as new designs of advanced modular reactors based on Gen IV technologies.

The Rolls-Royce SMR, a 470MWe PWR, formally entered GDA in early 2022. Other SMRs to begin the process include Holtec’s SMR-300 and GE Hitachi’s BWRX-300, both with funding support from the government’s Future Nuclear Enabling Fund.

See the ONR’s GDA pages for the latest information.

Development sites

The UK government is now holding a consultation to establish a new approach to siting nuclear power stations.

The current approach was set by the energy national policy statement in June 2011, which confirmed that eight sites are suitable for new nuclear power stations by 2025 – all are the sites of existing nuclear plant. New build proposals were developed for six of the sites, although most have been suspended. The other nominated sites are Heysham and Hartlepool.

EDF is building two EPRs at Hinkley Point, Somerset, with plans for another two at Sizewell, Suffolk.

EDF also proposed to work with investment partner China General Nuclear Power Corporation (CGN) to deploy the Chinese Hualong HPR1000 reactor at Bradwell, Essex. The plans have not progressed.

Wylfa, Anglesey, and Oldbury, Gloucestershire are now being brought under public ownership, with Great British Nuclear paying £160 million to acquite the two sites from previous owner Hitachi. In May 2024, the government confirmed that Wylfa is its preferred site for a third new gigawatt-scale development and opened an engagement exercise with interested technology vendors.

The Moorside site at Sellafield has no current developer following Toshiba’s withdrawal from the NuGeneration project in 2018, but remains a licenced site which could be developed by another player. NuGeneration proposed to develop up to 3.8GWe of new capacity at the site.

For more information, see the developers page.

Supply chain opportunities

UK companies, from top-tier suppliers to specialist SMEs, can potentially supply around 60 per cent by value of the work required for the current nuclear new build programme. To compete, many companies will have to develop new capabilities and build new relationships with industry leaders.

The civil nuclear supply chain presents particular opportunities for the metals industries. A nuclear power station contains many tens of thousands of tonnes of steel in a variety of forms. Examples include:

  • Reactor pressure vessels, turbine rotors, and other components which use major forgings and castings.
  • Construction steels for the containment structure.
  • Precision-engineered components such as high-pressure seals, pumps and valves.

Only a relatively small portion of the total power station requires nuclear-specific quality requirements. The bulk of plant has similar requirements to other power generation industries.

Companies in the top tier are working with UK suppliers to build a supply chain, and are inviting companies to register their interest. For more information about current opportunities, visit the EDF suppliers page and Rolls-Royce SMR supplier portal.

To help companies develop their business and technical capabilities to meet the needs of nuclear customers, we offer an array of supply chain development services including our flagship Fit For Nuclear programme.

For more information on the new build programme and the history of nuclear development in the UK, see the World Nuclear Association’s paper on Nuclear Power in the United Kingdom.