The UK needs new low-carbon electricity generation to meet the 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 are also decarbonised, 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 24GWe of nuclear capacity by 2050 – up to 25 per cent of the UK’s projected electricity demand.

The government aims to progress at least one nuclear new build project – most likely EDF’s Sizewell C – to final investment decision by the end of this Parliament in 2024, and two in the next Parliament. Subject to technology readiness, the 2024–29 phase may include a small modular reactor (SMR) project.

Current fleet

The UK currently has six operational nuclear power plants, owned by EDF, with a total capacity of 6.9GWe – but 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, or around 65 terawatt-hours (TWh) a year, from eight sites. Seven of these sites are based around advanced gas-cooled reactors (AGRs) built over the 1960s–80s, all of which are scheduled to be retired by 2030.

Two AGRs – Dungeness B and Hunterston B – have already ceased generation and are being defuelled. Another, Hinkley Point B, is set to cease operations in summer 2022. Decommissioning of the AGR fleet will be managed by 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

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

  • 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 GenIII+ PWR, with an output of 1.15GWe. AP1000s are under construction or operational at two sites in China and two sites 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 already in operation in Japan.
  • The Chinese Hualong HPR1000 is a 1.17GWe PWR, currently being deployed at three sites in China.

These four reactors have all completed the 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, with the first potentially online by 2030, 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.

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 most are now on hold. 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 has also proposed 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 – but ended development in 2020. Westinghouse and Bechtel are now developing plans for two AP1000s at Wylfa.

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.

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.