The UK Government’s official announcement of the Sizewell B life extension deal confirms the plant will keep generating electricity until 2055, adding 20 years to a station that opened in 1995 and was originally scheduled to close in 2035. The headline detail buried beneath the politics is the price: a contract for difference (CfD) with a strike price of £70.50 per MWh for the 2035-to-2055 period.
That figure matters. According to World Nuclear News, the £70.50/MWh strike price sits below both the rate agreed for Hinkley Point C and the current wholesale electricity price. For a government that has spent years defending the economics of new nuclear, that comparison is genuinely useful ammunition.
The Sizewell B Life Extension Deal in Numbers
The deal enables roughly £800m of plant investment by EDF, with the heads of terms still to be finalised later this year. The Guardian frames this as taking Sizewell B to a 60-year total operational lifetime, which is now a broadly standard ambition for pressurised water reactors in comparable markets.
EDF currently employs 620 staff and around 300 contractors at the Suffolk plant. Station director Robert Gunn said ‘major plant modifications and upgrades’ would be made, and that ‘securing another 20 years also safeguards existing jobs and allows us to continue to recruit another generation of Suffolk young people for the nation’s nuclear renaissance.’
Sir Patrick Vallance, minister for science, innovation, research and nuclear, put it plainly: ‘It means we’ve got more clean electricity for that period. That’s two and a half million homes’ worth of electricity and 900 jobs.’
Energy Secretary Ed Miliband was equally direct. ‘Nuclear power is vital for our energy security, and this extension will help produce the clean power our country needs,’ he said, according to World Nuclear News.
Sizewell B is the UK’s only pressurised water reactor and currently provides around 3% of the country’s electricity, enough to power more than two million homes. EDF calculates the extended output would cover every home in East Anglia for almost 45 years.
Centrica, Critics, and the Question of Concentration Risk
The Financial Times reported that Centrica was in talks with the government alongside EDF over the approximately £800m investment package. If confirmed, that would bring a second major energy group into the ownership picture at a plant that carries significant strategic weight.
Opposition to the extension is not trivial, and the strongest of it does not come from anti-nuclear ideology alone. Chris Wilson of the campaign group Together Against Sizewell C (TASC) raised a point that deserves more than dismissal: the combined output of Sizewell B and the planned Sizewell C represents 4.4 GW of generation concentrated in a single stretch of East Suffolk coastline.
Wilson argued that this ‘concentrates immense power generation in East Suffolk, making the area a prime target for malicious attacks with potentially catastrophic environmental consequences.’ He added that TASC believed this ‘centralization increases the national grid’s exposure to massive blackouts caused by a single accident or technical failure.’
These are engineering and security arguments, not simply environmental ones. The Office for Nuclear Regulation (ONR), the statutory independent regulator, said it had 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.’ That is regulators doing their job; it is not a rubber stamp.
Wilson also pointed to radioactive waste as a ‘multi-generational financial and environmental liability,’ leaving future generations with ‘the insurmountable challenge of safe, millennia-long, highly radioactive nuclear waste isolation, amid a changing climate.’ These are legitimate long-run costs that do not disappear simply because the short-run economics of the CfD look attractive.
My read is this: a £70.50/MWh strike price for 20 years of low-carbon baseload, from infrastructure that already exists, is a rational deal for a country facing both a capacity gap and a net-zero target. The concentration-risk argument from TASC is worth taking seriously and should shape how Sizewell C’s planning proceeds. The waste question is real, but it is not an argument unique to this extension; it applies to every nuclear plant already operating.
The heads of terms are agreed. The finalised contract is due before year-end. If the Hinkley Point C comparison holds, and the wholesale price stays above £70.50/MWh, the Treasury will find this deal considerably easier to defend than it expected.
