As part of efforts to meet climate targets and boost energy security, Britain is seeking to increase its nuclear power capacity by 2050 to 24 gigawatts (GW), equivalent to about a quarter of projected electricity demand, from about 14% today.

Large new nuclear projects with high upfront costs have struggled to attract financing and the government hopes some older plants could be replaced by a fleet of SMRs that can be made in factories with lower costs and faster construction.

"Holtec will be investing approximately 600 million pounds in the construction, design and build of a new factory and production site over the next 15 years," Gareth Thomas, Director of Holtec Britain, said.

Local authorities and businesses will be invited to submit expressions of interest to host the factory, outlining which sites could be available and how ready they would be for work to start on the factory.

The factory could provide around 400 highly-skilled jobs in the next three-to-five years, Thomas said.

Britain's government last year opened its own competition to help develop SMR technology with the aim of deploying projects in the 2030s.

Holtec Britain leads a consortium, including South Korea's Hyundai, whose SMR-300 technology is one of six that have been short-listed in the government competition run by the Great British Nuclear (GBN) body.

The other five short-listed companies for the GBN competition are Rolls Royce SMR EDF, GE-Hitachi Nuclear Energy International, NuScale Power, and Westinghouse Electric Company UK.

Holtec already has an SMR factory in New Jersey in the United States, but has said a UK site could provide a base to export its technology to Europe and the Middle East.

($1 = 0.7822 pounds)

(Reporting By Susanna Twidale; editing by Barbara Lewis)

By Susanna Twidale