The United Kingdom is focused on diversifying its energy mix away from fossil fuels to boost energy security and support decarbonisation aims. This includes expanding its nuclear power capacity with the development of two large-scale nuclear plants - Sizewell C and Hinkley Point C, as well as developing small modular reactors (SMR). However, its nuclear ambitions have not quite gone to plan, following years of delays and rising construction costs.
Sizewell C in Suffolk, eastern England, received its planning approval in 2022, was greenlit in 2025, and is expected to be operational by around the late 2030s. Investment for the development comes from the government, EDF Energy, Centrica, La Caisse, and Amber Infrastructure Limited. The project is expected to create 17,000 jobs during peak construction, including 7,900 in Suffolk. Once operational, the nuclear plant will produce up to 3.2 GW of clean electricity to power up to 6 million homes.
The government expects the plant to cost around £38 million to develop and says it could provide around £2 billion a year in savings from the electricity system, compared to using other low-carbon technologies. However, Sir Geoffrey Clifton-Brown, the chair of the public accounts committee, which oversees the work of the National Audit Office (NAO), warned that “Sizewell C is a project of exceptional scale, complexity and significance for taxpayers… Experience from comparable nuclear projects in the UK and overseas highlights their vulnerability to delays and cost overruns.”
To date, the French nuclear firm EDF has invested £1.1 billion for a 12.5 percent stake in the project, while the U.K. government has invested £14.2 billion as the majority stakeholder. The NAO fears that if not properly managed, construction could run significantly over budget, as seen with other nuclear developments in recent years. This would make the break-even time much longer for consumers footing the construction costs through their taxes.
The NAO has, therefore, urged the government to mitigate the risk by using “close monitoring, greater transparency to parliament, and by securing value for money from the significant public and private investment”.
Lessons for building Sizewell C come from the construction of EDF’s Hinkley Point C plant, the first nuclear plant to be developed in the U.K. in over a decade. Hinkley Point C was approved by the U.K. government in 2013 and was greenlit in 2016. It is expected to begin operations in 2030, a year later than originally planned.
The project has faced several delays and price increases, the most recent of which was announced by EDF in February, adding a projected £2.16 billion. The plant is now expected to cost around £35 billion in total, almost double the original £18 billion 2016 estimate. EDF’s CEO, Bernard Fontana, said the new forecasts were “more realistic” and said that the 2030 launch of operations was “within a range that has not changed” since 2024, when it said operations would start between 2029 and 2031.
Once operational, Hinkley Point C is expected to provide around 7 percent of Britain’s electricity demand. While EDF’s two U.K. nuclear projects could help diversify the country’s energy mix and reduce reliance on fossil fuels, critics worry that the development of the two plants will face further delays and come in significantly over budget. EDF’s only other nuclear project using the same reactor type, at Flamanville in France, became fully operational in December after a delay of over 12 years; meanwhile, costs soared from an initial estimate of £2.85 billion to over £11.4 billion.
In 2025, the U.K. was deemed the “most expensive place in the world” to build nuclear power plants in a government review. This was largely owing to “overly complex” bureaucracy around the sector. Nuclear Regulatory Taskforce said that “radical reset” of the rules around nuclear power could save Britain “tens of billions” in costs and reverse the industry’s “decline” in recent years. This suggests that the government must work to streamline bureaucratic processes without compromising safety and consider other cost-cutting options to avoid cost increases in nuclear development.
At the time, the Taskforce chair, John Fingleton, stated, “Our solutions are radical, but necessary. By simplifying regulation, we can maintain or enhance safety standards while finally delivering nuclear capacity safely, quickly, and affordably.”
In 2024, the U.K. government announced a target to increase the country’s nuclear power capacity fourfold, to 24 GW by 2050. This will be achieved through the development of Sizewell C and Hinkley Point C, as well as through the deployment of innovative small-scale nuclear technologies. This is an ambitious target, but through the development of a wide range of nuclear technologies, it could be achievable.
The U.K. government has already published an Advanced Nuclear Framework for the deployment of innovative nuclear projects. Now, it must ensure that its regulatory frameworks and energy policies align with its nuclear power targets and help facilitate nuclear energy development.
By Felicity Bradstock for Oilprice.com
