The National Audit Office (NAO) has warned that the £38bn Sizewell C nuclear plant in Suffolk carries 'significant uncertainty' and may not deliver net benefits to UK households until at least 2064. The spending watchdog stated that while the potential benefits are considerable, they remain uncertain, whereas the risks are immediate, substantial, and borne by the public.
The government claims the reactor, expected to power 6 million homes from the late 2030s, could save £2bn annually compared to other low-carbon technologies. However, the NAO cautioned that household savings could be outweighed by construction support costs until almost halfway through its 60-year operational life, with delays or cost overruns extending the break-even point.
Sir Geoffrey Clifton-Brown, chair of the public accounts committee, described Sizewell C as a project of 'exceptional scale, complexity and significance for taxpayers,' noting that comparable nuclear projects in the UK and abroad have been vulnerable to delays and cost overruns. The project is developed by EDF, with the UK government as majority stakeholder, alongside Centrica, La Caisse, and Amber Infrastructure.
Nigel Cann, chief executive of Sizewell C, defended the costs as an 'investment in lower long-term electricity costs' that will deliver value for the rest of the century. He highlighted the project's creation of thousands of jobs and £5bn spent with UK suppliers. A government spokesperson added that investing in large-scale nuclear is the only way to escape volatile global gas markets.
Households began paying for Sizewell C via energy bills in January under a regulated asset base model, a shift from the Hinkley Point C deal. Critics, including Stop Sizewell C, warn that delays could leave bill payers supporting the project without receiving power for longer than expected, while investors face no risk. The NAO urged the government to mitigate risks through close monitoring and transparency.
