£1.2billion investment across 2026-28 to help boost reliability and output

• Sizewell B and Torness power stations performed strongly in 2025 and total UK nuclear output from the five generating stations was 32.9TWh, 12% of total UK consumption  
• In September 2025, a further year was added to the forecast lifetimes of Heysham 1 and Hartlepool, taking them out until March 2028
• EDF (80%) and Centrica (20%) have an ambition to generate from the AGR power stations until at least 2030, subject to plant inspections, reliability and regulatory support. Investment to support that goal will total £1.2bn over the next three years (2026-28)
• Work continues to agree a commercial model that is required to support a 20-year Sizewell B life extension (2035-2055) and unlock £800m of investment in the station  
• Hunterston B and Hinkley Point B power stations are on schedule to transfer into UK Government ownership in 2026 after defueling was completed in line with the plan.

EDF’s Nuclear Operations business has today (21 January) published its annual fleet update, a review of 2025 performance and an outline of future developments.  2025 was a milestone year for the UK nuclear sector with the approval of Sizewell C, an important review into regulation of the nuclear sector led by John Fingleton, a Government decision on the future of the Wylfa site and new project proposals announced for the Cottam site (Holtec, EDF, Tritax) and Hartlepool (X Energy, Centrica).

This fleet update is published as EDF’s nuclear operations business prepares to recognise its own milestone, the 50th anniversary of when the UK’s first Advanced Gas-cooled Reactors started producing zero carbon electricity. Hinkley Point B connected to the grid on 5th February 1976, followed by Hunterston B the next day. Fifty years later, both of those stations are preparing to transfer to the Nuclear Decommissioning Authority (NDA) following the successful completion of defueling, on time and on budget. Hunterston B will be the first to transfer in April 2026.

Dr Mark Hartley, Managing Director of EDF’s Nuclear Operations business said: “In November, the UK Government said that the retirement of the AGRs risks leaving a dangerous gap in Britain’s low-carbon energy supply. It is our ambition to generate from the remaining AGR stations for as long as it is safe and commercially viable to do so and we will keep their lifetimes under review to assess whether further life extensions can be achieved.    

He continued: “Sizewell B had a strong year, operating for 99% of the time and delivering the second highest output in its 30-year history, once again demonstrating the value of nuclear as a stable baseload generator.”

Minister for Nuclear, Lord Vallance said: “Nuclear is a vital component of our energy mix, providing clean homegrown power for millions of homes and supporting energy security while employing thousands of people across the country. 

That is why it is excellent to see EDF investing in our existing nuclear power stations, and we are driving a new age of nuclear – backing Sizewell C in Suffolk and small modular reactors in North Wales.” 

The annual fleet update outlines the UK nuclear fleet’s 2025 generation performance. Output last year was 32.9TWh, 12% lower than in 2024 due primarily to an extended outage at Hartlepool power station. This output represents about 12% of UK electricity demand and is enough to power every home in the UK for more than four months.  

Output was over treble the amount originally expected from these stations when EDF acquired the fleet in 2009. The youngest of the Advanced Gas-cooled Reactor stations (Torness and Heysham 2) were originally due to stop generating in 2023 but investment in the fleet so far of £8.6 billion, along with careful stewardship, has enabled four stations to stay online, preventing Sizewell B being left as the UK’s sole generating nuclear station. EDF plans to return output to around 36TWh in 2026 and is due to invest more than £1.2billion over the 2026-28 period.  

In September 2025, a further year was added to the forecast lifetimes of Heysham 1 and Hartlepool meaning they are currently due to generate until March 2028.  

EDF believes a 20-year life extension for Sizewell B is technically feasible and would provide a reliable, clean source of power to 2055 and beyond. Negotiations are ongoing with the UK Government to agree a long-term price for the power that will enable the required investment to make this extension happen.

Read EDF’s full UK Nuclear Fleet Stakeholder Update.  

Notes to editors:  

• Hunterston B and Hinkley Point B are due to transfer to the Nuclear Decommissioning Authority (NDA) for its subsidiary Nuclear Restoration Services (NRS) to carry out decommissioning. Hunterston B is due to transfer in April 2026 and Hinkley Point B in October 2026.
• In 2025 Sizewell B generated 10.4TWh with a load factor of 99% and Torness generated 8.6TWh with a load factor of 82%. A power plant's load factor measures its actual energy output compared to its maximum possible output over a period.  
• Heysham 1 and Hartlepool are due to generate until March 2028, following a life extension decision in September 2025. Torness and Heysham 2 were not in scope for that review and are currently due to generate until March 2030. These dates will be kept under review.
• The Prime Minister’s Strategic Steer to the Nuclear Sector said that the retirement of the AGRs “risks leaving a dangerous gap in Britain’s low-carbon energy supply.”