The UK needs new low-carbon electricity generation to replace current ageing plant, and to meet the commitment to reduce net greenhouse gas emissions to zero by 2050.

With UK electricity demand likely to quadruple by 2050 as transport and heating are decarbonised, the UK will potentially need to quadruple its low-carbon generation.

The UK currently has 15 reactors with a total generating capacity of 10 gigawatts of electricity (GWe), operated by EDF Energy. These stations generate around a fifth of the UK’s electricity – and all but one are scheduled to be retired over 2023–30. The exception is Sizewell B, the UK’s only pressurised water reactor (PWR), which began operations in 1995 and is scheduled for decommissioning in 2035.


Four reactor designs have been or are being formally considered for UK new build: the Framatome EPR (originally the Areva European Pressurised Reactor), Westinghouse’s AP1000, Hitachi-GE’s Advanced Boiling Water Reactor (ABWR), and the Chinese Hualong HPR1000.

Both the EPR and AP1000 are generation III+ PWRs, offering a range of safety, economic and operational improvements over previous designs.

The EPR has an output of 1600MWe. Four EPRs are under construction in Finland, France and China, with the first in China entering commercial operation in late 2018.

The AP1000 has an output of 1150MWe. AP1000s are under construction or operational at two sites in China (with first generation in 2018) and two sites in the US.

Both the EPR and AP1000 have completed a 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 Hitachi-GE ABWR is a significantly different design to the Areva and Westinghouse PWRs, operating at lower pressures and temperatures but requiring much larger pressure vessels. The 1300MWe ABWR completed GDA in December 2017. Four ABWRs are already in operation in Japan.

The 1170MWe Hualong HPR1000 is a generation III PWR, currently being deployed at three sites in China. It completed the third phase of GDA in February 2020, with CGN aiming for approval around 2022.

The UK is also considering the development of small modular reactors based on Gen III+ technologies, with the first potentially online by 2030, as well as new designs of advanced modular reactors based on Gen IV technologies. None have yet entered GDA.

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

Development sites

The UK Government’s energy national policy statement in June 2011 confirmed that eight sites are suitable for new nuclear power stations by 2025 – all are the sites of existing nuclear plant. New build proposals have been developed for six of the sites (see map), although some are now on hold. The other nominated sites are Heysham and Hartlepool.

EDF Energy is proposing to build two EPRs at Hinkley Point, Somerset, and two at Sizewell, Suffolk – construction at Hinkley Point C is now well underway. EDF also proposes to work with investment partner China General Nuclear Power Corporation (CGN) to deploy the Chinese Hualong HPR1000 reactor at Bradwell, Essex.

Horizon Nuclear Power, owned by Hitachi, planned to build two ABWRs at Wylfa, Anglesey, and at least two at Oldbury, Gloucestershire. Hitachi confirmed it was ending its involvement in September 2020.

The Moorside site at Sellafield has no current developer following Toshiba’s withdrawal from the NuGeneration project in November 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 opportunities with EDF, go to:

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.