Sizewell C, the 3.2GW UK nuclear power station under construction in Suffolk and majority owned by the government, has provided a report to parliament on progress made since the project received its Development Consent Order (DCO) one year ago.

Sizewell C, majority-owned by the British government and EDF, is expected to feature two EPRs producing 3.2 GW of electricity, enough to power the equivalent of around six million homes for at least 60 years. It would be a similar design to the two-unit plant under construction at Hinkley Point C in Somerset, with the aim of building it more quickly and at lower cost as a result of the experience gained at Hinkley Point.

In January 2024, the UK government announced an investment of £1.3bn ($1.6bn) to support the project, The UK Department for Energy Security & Net Zero (DESNZ) in September 2024 revealed a new subsidy scheme – the Sizewell C Development Expenditure (Devex) Scheme – “to enable continued support to the development of the proposed new nuclear power plant Sizewell C to the point of a Final Investment Decision (FID). The total value of support allowed by the scheme is £5.5bn. The project received an additional £2.7bn in funding from the government in the 2024 Budget.

The first Sizewell C Progress Update was presented by Sizewell C’s joint managing directors, Julia Pyke and Nigel Cann during Nuclear Week in Parliament. The update included an independent due diligence commissioned for HSBC by consultancy firm Enco, which praised the project’s progress, stating that “Sizewell C is likely the best prepared nuclear project in modern nuclear history”. The assessment concluded: “The Sizewell C project has high chances of avoiding pitfalls that led to a significant schedule and cost overruns on many nuclear projects, including those with EPR reactor models.”

The report noted that

  • Sizewell C is on time and on budget;
  • Development is demonstrating the benefits of replicating Hinkley Point C’s reactor design, with £1bn of cost savings identified so far through innovation and replication;
  • Contracts worth £2.5bn have already been agreed with 290 suppliers across the UK;
  • 1,000 people are now employed on site, with a 60% female executive team – its apprenticeship recruitment has been 50% female since the programme began in 2021 and the workforce is currently over 40% female;
  • Sizewell C will eventually support over 70,000 jobs across the UK, and over 70% of the construction spend will go to UK companies;
  • The project will generate around £2.92 of economic value (GVA) for every £1 invested during construction and will create over £100bn of value for the UK over the lifecycle of the project;
  • Sizewell C has strong local support, with most people in East Suffolk wanting the project to go ahead according to the most recent ICM polling.

Commenting on the update, Pyke and Cann said Sizewell C “is already a massive driver of growth in the UK, and the team has made extraordinary progress in the year since we received permission to begin construction”. They emphasised that the project is on time and on budget and has a stable cost base. “That’s in no small part because we’re using exactly the same reactor design as Hinkley Point C, which means we’ve benefitted from the research and innovation already done there.” They added: “Sizewell C is the most important energy project that the UK is likely to undertake in the next two decades, and its benefits will be felt in every constituency across the country.”

 However, in January, the Financial Times reported that the estimated cost of constructing Sizewell C had increased to £40bn, nearly double the initial projections by EDF. The FT said the revised figure, reflects 2025 prices and is attributed to rising construction costs and lessons learned from delays and overruns at EDF’s Hinkley Point C project in Somerset. The FT cited a senior government official and two industry insiders who characterised the £40bn estimate as a reasonable projection. However, a spokesperson for DESNZ said the figure was “speculative” adding that discussions with potential investors were “commercially sensitive”.

Also in January, France’s Court of Auditors noted that in the UK EDF is confronted at the Hinkley Point C construction site with “a considerable increase in costs accompanied with a new delay of two years, and with a heavy financing constraint caused by the withdrawal of the Chinese co-shareholder”. Meanwhile, at the planned Sizewell C project, “delays are already accumulating, even before the investment decision has been taken”. The court recommended that EDF should not make a final investment decision on Sizewell C “before obtaining a significant reduction in sound financial exposure in Hinkey Point C”.