Ministers have made available a further £341m of previously allocated funding for development work on the project, adding to the £170m the project was granted just last month.
The money will be used to ramp up activity at the Suffolk site, supporting continued preparation works such as constructing onsite training facilities for apprentices, further development of the plant's engineering design, and investments in the local community. The money builds on the government's existing £870m stake and will help drive progress towards the long-standing objective of reaching a Final Investment Decision on a new large-scale nuclear project this parliament.
Once complete, the facility is expected to cost at least £20bn and generate energy at a more expensive price when compared to renewables such as wind and solar.
The government has said it wants to rapidly expand the amount of nuclear energy generated in the UK in a bid to meet a quarter of the country's electricity demands by 2050.
The Sizewell C project is expected to commence before 2024, with construction taking between nine and 12 years, depending on developments at the oft-delayed and over-budget Hinkley Point C nuclear power station. French energy giant EDF recently pushed back Hinkley Point's first day of operation to September 2028.
It is envisaged that Sizewell C would provide low-carbon power to the equivalent of 6 million homes over 60 years – saving the UK as many as 9 million tonnes of CO₂ emissions annually.
Nuclear minister Andrew Bowie said: "Sizewell C will be a significant part of the revival of nuclear energy in this country. Today's funding announcement is a clear demonstration of the government's commitment to this vital project, and will mean the site will be shovel-ready – and work will be able to start – much more quickly."
Like Hinkley Point C in Somerset, Sizewell C would comprise two reactors, generating a total of 3.2GW of electricity – equivalent to 7 per cent of the UK's electricity needs.
Sizewell C company joint managing director Julia Pyke said: "This is great news and puts us in an even stronger position to start full construction. It will also allow us to implement several community schemes over the next few months.
"We want people living near Sizewell C to see the benefits of the project as soon as possible and we're looking forward to getting started on a range of proposals, which will bring real improvements to the area well before the main construction gets underway."
The news follows the launch of a new arms-length body Great British Nuclear, which is responsible for helping to deliver new nuclear facilities in the UK. Its initial focus will be on small modular reactors, but further large gigawatt-scale projects will also be considered in the future.
