EDF is currently the only developer building new nuclear plant in the UK.

Under the UK regulatory system, developers act as the licensees for nuclear new build. They are responsible for arranging financing, and securing planning and regulatory approval for new power plants.

EDF and its investment partner CGN, and the currently inactive development groups Horizon and NuGen, are introduced below.


EDF is proposing to build four EPR reactors, with the first two units now under construction at Hinkley Point C, Somerset.

EDF entered the UK nuclear generation market in 2009 with its acquisition of British Energy, which operated eight formerly state-owned nuclear power stations. UK utility group Centrica retains a 20 per cent stake in the existing stations, but withdrew from a proposed new build collaboration in 2013.

EDF operates through a UK subsidiary called Nuclear New Build Generation Ltd (NNB GenCo). The venture is building two EPR generators at Hinkley Point, Somerset, and plans to build another two at Sizewell, Suffolk. The four reactors will have a total capacity of 6.4GWe.

EDF made a positive final investment decision (FID) on Hinkley Point C in July 2016. The UK government subsequently confirmed its support and signed contracts in September 2016.

Construction is now well underway on both reactors at Hinkley Point C, with the concrete base for the first reactor completed in June 2019, and the second in May 2020. As of January 2024, first electricity generation is expected between 2029 and 2031, with the second reactor expected to complete around two years after the first.


At the start of the current new build programme in the mid-2000s, the UK government took a market-led approach: all new nuclear plant would be wholly financed and constructed by the private sector, with no direct subsidy. That meant that each developer’s decision to invest depended on economic and political conditions, and financial factors such as capital costs.

Commercial terms for Hinkley Point C were agreed by EDF and the UK government in October 2013. Electricity from Hinkley Point C will receive a guaranteed price under the contract for difference (CFD) regime which also applies to windfarms and other low-carbon sources. The CFD strike price was £92.50/MWh, although this increases in line with the consumer price index.

If EDF confirms that it will also build new capacity at Sizewell C, the strike price for Hinkley Point C will be reduced to £89.50/MWh (plus inflation) to reflect economies of scale.

Hinkley Point C now has an estimated cost of £31-34 billion at 2015 values.

Sizewell C will be financed under the Regulated Asset Base (RAB) financing model rather than CFD. RAB is designed to provide a more attractive investment profile for major infrastructure projects by reducing project risk for the investor and providing an income stream during construction.

The Nuclear Energy (Financing) Act, which allows the use of RAB for nuclear new build, received royal assent in March 2022. The government has also established the £120 million Future Nuclear Enabling Fund to help potential nuclear projects move towards commercial maturity.

Sizewell C

EDF has said that it plans to build Sizewell C around five years behind Hinkley Point C, and submitted its formal planning application in May 2020. The development consent order was granted in July 2022 and triggered in January 2024, allowing construction to begin. The government announced in December 2020 that it was entering negotiations with EDF, with the aim of a final investment decision in 2024.

In November 2022, the government announced a £679 million investment in Sizewell C to support the project’s continued development, and a further £1.3 billion in January 2024 to support construction. Potential private co-investors were invited to register interest in September 2023.

The ONR granted a nuclear site licence to Sizewell C in May 2024. Under the terms of the licence, the site’s developers will still need ONR’s permission to proceed with nuclear-related construction.


The procurement process for Hinkley and Sizewell is overseen by NNB GenCo, and operated by EDF Procurement in Paris. Requests from EDF have been for large packages of work or the supply of specialised plant. Smaller suppliers are unlikely to prequalify on their own, and will need to form consortiums or supply agreements with higher-tier suppliers.

EDF has seven top-tier suppliers for Hinkley Point C:

  • Bouygues TP/Laing O’Rourke (Bylor) – civil works.
  • Balfour Beatty (replaced Costain in 2017) – marine work.
  • Alstom Energy (now part of GE) – turbines.
  • Framatome (formerly Areva) – instrumentation & control, nuclear steam supply system, fuel.
  • Balfour Beatty Bailey – electrical work.
  • Cavendish Boccard Nuclear – mechanical pipework and installation.
  • Actan – HVAC.

Other key suppliers include:

  • Rolls-Royce – heat exchangers, emergency diesel system.
  • Rolls-Royce/Nuvia – reactor coolant processing systems.
  • Weir – large pumps for cooling water.
  • SPX Flow – main pumps for feedwater and cooling water systems.
  • ABB UK – power transmission.
  • Ovivo – intake water filtration systems.
  • Laing O’Rourke – workers’ campus accommodation.
  • Premier Interlink WACO UK Ltd – temporary buildings.

Partnership with CGN

EDF is working with CGN (China General Nuclear Power Corporation) to deliver Hinkley Point C, with CGN taking a 33.5 per cent investment share. The two companies have formed a joint venture company, General Nuclear System Ltd, to manage the project, with CGN investing through its UK subsidiary General Nuclear International Ltd.

CGN will not be involved in Sizewell C, following the UK government’s decision in November 2022 to invest directly in the project. The two groups also proposed to collaborate on deploying the Hualong HPR1000 reactor at Bradwell in Essex, but arrangements are widely expected to change.

CGN has said that it intends to complete Bradwell B around 2030, but negotiations with government are yet to start.

Further information

Inactive developers

Horizon Nuclear Power

Horizon Nuclear Power was originally a joint venture between E.ON UK and RWE npower, acquired by Hitachi Ltd of Japan in 2012. Hitachi confirmed in January 2021 that it was winding up Horizon, and withdrawing its application to build a new nuclear power station at Wylfa Newydd.

Horizon was founded as a 50/50 joint venture between E.ON UK and RWE npower, and acquired land and agreed connections for Wylfa, Anglesey, and Oldbury, Gloucestershire, with plans to build around 3GWe of new capacity at each site.

Hitachi acquired Horizon in November 2012, with plans to build two of its own 1300MWe advanced boiling water reactor (ABWR) plants at each site. The ABWR completed the generic design assessment (GDA) process in December 2017.

Horizon suspended its projects in January 2019, and announced in September 2020 that it was ending development of new nuclear plant in the UK. The company unsuccessfully sought an alternative developer to take over the Wylfa Newydd project.

Wylfa and Oldbury remain government-designated development sites for nuclear new build, and were acquired by Great British Nuclear in March 2024.


NuGeneration Ltd (NuGen) was established as a joint venture between GDF Suez and Iberdrola. It acquired the Moorside site at Sellafield, Cumbria, with the intent of building up to 3.8GWe new capacity.

In 2014, Toshiba acquired all of Iberdrola’s 50 per cent stake plus 10 per cent from GDF Suez (now Engie), which will remain as operator. In 2017, Engie transferred its remaining 40 per cent stake, leaving Toshiba as sole owner of NuGen.

Toshiba subsequently launched a strategic review of its ownership of NuGen and, in November 2018, announced that it was liquidating NuGen after failing to secure a buyer.

Moorside remains a government-designated development site for nuclear new build.