The Government's Nuclear Decommissioning Authority has sold a development option on a Sellafield site to Toshiba and GDF Suez for £220m.
The agreement is a major step towards the development of a new nuclear power station at Moorside, West Cumbria, that the NDA said will create at least £10bn worth of investment and thousands of jobs.
NuGen is a joint venture between Toshiba and GDF Suez. In January Toshiba agreed to buy 60% of NuGen for £102m, buying out previous partner, Spanish firm Iberdrola.
NuGen plans to use reactors made by Toshiba-owned Westinghouse at the site, with three reactors to come online from 2024 which will deliver 3.4GW of new nuclear capacity, enough to power up to 6m homes.
Prime Minister David Cameron said: "Today we can announce the huge investment being made by Toshiba and Westinghouse – over £200m – into the rebuilding of the British nuclear industry, specifically in the North West of our country, in a project that could provide as many as 14,000 jobs during the construction phase, and many thousands of jobs ongoing, as well as providing low-carbon, base load electricity for Britain. This is a symbol of the growing relationship between Britain and Japan."
John Clarke, chief executive of the NDA, said: "This is a significant step forward for the plan to establish new nuclear in West Cumbria. Together with our nuclear partners we are seeing the emergence of West Cumbria as a centre of nuclear excellence across the whole span of the industry from new build to decommissioning and waste management."