What is Sizewell C – and why is it so controversial?

Sky News

10-06-2025

The UK is one step closer to a new nuclear power plant after the government announced a further £14.2bn in funding.
Sizewell C, near the town of Leiston on the Suffolk coast, is due to be up and running by the mid-2030s.
While the government claims the new facility represents a "golden age of clean energy" and says it will create thousands of jobs - those against it warn of the catastrophic consequences of a nuclear accident and damage to the local environment.
Here we look at what is due to be built at the Sizewell site - and why the project is so controversial.
What is Sizewell C?
The new site will house two nuclear reactors - generating up to 3.2 gigawatts of electricity, which is enough to power six million homes.
The government says it could meet 7% of the country's total energy needs for up to 60 years.
It was initially proposed by the French energy company EDF and China's General Nuclear Power Group, but the previous government bought the Chinese company out of its 20% stake in 2022.
Together, the UK government and EDF now own 83.5% of the site.
It is located near Sizewell beach - next to Sizewell A, a decommissioned nuclear site that opened in 1967, and Sizewell B, which is still running - and was the last nuclear site to open in the UK in 1995.
Previous funding announcements mean the state has now invested a total of £17.8bn, with a final funding model due to be released this summer after private investors are secured to bridge the gap to the total £20bn cost.
Taxpayer money is expected to contribute £700m.
How long has it been in the making?
The project dates back to 2008, when then Labour Prime Minister Gordon Brown declared the UK needed to boost its nuclear capacity.
There are four nuclear sites running in the UK - at Heysham, Hartlepool, Torness, and Sizewell B.
In 2010, the Conservative-Liberal Democrat coalition earmarked Sizewell as a potential new site.
EDF began consulting with locals in the area in 2012, finally submitting its development consent order in May 2020.
It was granted in July 2022 despite the Planning Inspectorate's recommendations it should be blocked over environmental concerns.
It also fought off a judicial review at the Court of Appeal brought by protest group Together Against Sizewell C.
Construction by EDF is due to start in the next year - and is set to take between nine and 12 years.
Why are people against it?
Two campaign groups - Together Against Sizewell C and Stop Sizewell C - have spearheaded efforts to block the site.
Locally, they say construction will damage 150 hectares of land nearby, which is home to two different nature reserves and thousands of birds, animals, and plant species. The appeal also cited concerns it would compromise local water supplies and may run over budget or fail to even get off the ground like the now-scrapped HS2 trainline.
More generally, nuclear power is very controversial.
While it does not produce carbon emissions like traditional fossil fuels, any nuclear activity is exceedingly high-risk.
Nuclear fission is the process by which uranium atoms are broken down into smaller particles to produce heat, which is then boiled to create steam that powers turbines to create electricity.
The International Atomic Energy Agency says all its regulated sites are the "safest and most secure facilities in the world" and subject to strict independent safety measures.
But high-profile nuclear accidents, although incredibly rare, have leaked deadly radiation into the atmosphere, killing people and likely poisoning others for generations to come.
These include the explosion at the Chernobyl plant in Ukraine in 1986 and the partial meltdown of one of the reactors at the Fukushima nuclear plant in Japan following a tsunami in 2011.
Nuclear fission also produces huge amounts of radioactive waste, which has to be safely stored for hundreds of years and anti-nuclear campaigners worry about the safety of these storage sites.
What are the arguments for it?
The government wants to use nuclear energy to help meet its target of net zero greenhouse gas emissions by 2050.
Chief executive of the Nuclear Industry Association Tom Greatrex has described Sizewell C as a "huge step forward" both for net zero - and energy security.
The Ukraine war compromised global gas and oil supplies, much of which came from Russia, sending prices rocketing.
Since then, Ukraine's Western allies have made efforts to become more autonomous with energy production.
Britain's nuclear sector grew by a quarter to £20bn in the three years to 2024, with another site at Hinkley Point in Somerset currently under construction.
Some countries, like France, where EDF is based, already rely heavily on nuclear power.
Sizewell C will also create 10,000 new jobs and 1,500 apprenticeships, boosting the local and UK economy.
Around £330m has been tendered to local companies in contracts, with 70% of all those commissioned going to 3,500 British suppliers.
Mr Greatex said: "Sizewell C will provide reliable low-carbon power for more than 80 years, cutting gas use, creating thousands of high-quality skilled jobs, and long-term investment and opportunity up and down the country."