EDF and the UK Government have signed the Heads of Terms for a Contract for Difference (CfD) agreement to extend the operating life of the Sizewell B NPP in Suffolk, which was scheduled to close in 2035. Now this will be extended to 2055, with EDF funding a major refurbishment of the NPP during planned outages over the next 15 years, costing around £800m ($1,060m).
The single unit Sizewell B is a 1,188 MWe pressurised water reactor (PWR). The nuclear island is based on a Westinghouse four-loop Standard Nuclear Unit Power Plant System (SNUPPS) initially designed in the 1970s but with additional redundancy and diversity in the safety systems, and other modifications. The containment design was not based on SNUPPS but was designed by National Nuclear Corporation (bought by Amec Foster Wheeler in 2005) in conjunction with Bechtel. Sizewell B is the UK’s only PWR and supplies energy to more than 2m homes, producing 3% of the UK’s energy.
The proposed agreement covers the period from 2035 to 2055 and includes a strike price of £70.50/MWh (2025 prices). Sizewell B produces baseload power, available 24/7 in all weather conditions. Extending the operational life of the station is a cost-effective way to increase the UK’s energy generation. The UK Government and EDF are expected to finalise the CfD later this year.
The lifetime extension works will be delivered over the next 15 years during the station’s outages, which occur every 18 months. This allows critical works to be done while minimising the time the station is not producing power and avoiding the need for lengthy shutdowns.
The investment works will include a new environmental monitoring system, similar to that being built into Hinkley Point C, and new automated plant monitoring systems. The investment will also go on replacing pipework, valves and pumps across the site. There will also be additional funding for ongoing detailed technical analysis and plant inspections. The extension of 20 years will mean that Sizewell B has the potential to generate around an additional 180 TWh of power.
“Global events demonstrate time and again how vital it is for the UK to secure long term, low-carbon, homegrown electricity, which protects British households and businesses from market volatility,” said EDF UK CEO Simone Rossi. “Extending the life of the plants we already have alongside building new ones is central to EDF’s strategy.”
Minister for Science, Innovation, Research & Nuclear Lord Vallance said: “This deal protects billpayers and boosts the country’s energy security by continuing to provide clean, secure power for millions of households. By backing Sizewell B, we are delivering a golden age of nuclear and maintaining 900 skilled jobs in Suffolk.”
A spokesperson for the Office for Nuclear Regulation (ONR) said it worked “constructively with EDF on their plans to extend the life of the nuclear plants by reviewing technical and safety case considerations while ensuring it achieves the required standards of safety and security in the most practical way…. The ongoing safety and security of operations at any nuclear site must be fully demonstrated to us as part of ongoing regulation which will be informed by our extensive, proportionate and targeted inspection and assessment regime.”
