French nuclear power group Areva said on Tuesday it was part of a consortium retained for a major contract in Britain to handle radioactive metallic waste.
The treatment of waste materials from nuclear power plants is a highly expensive and environmentally controversial issue.
Areva, which did not divulge the value of the deal, said it would work with British companies Mace and Atkins in the joint-venture called a.m.a.
The consortium would build a "customised waste treatment plant to process legacy materials from Magnox fuel currently present on the site" at Sellafield in the northwest of England, the company said in a statement.
A main technique for preparing nuclear waste for long-term storage as it sheds radioactivity is to encase it in protective materials.
The consortium "will complete the engineering design, procurement and construction, and commissioning related activities for the facility," the statement said.
Areva's senior vice president for the contract, Dominique Mockly, said it was committed to "providing the best value to the UK nuclear industry while ensuring that these projects ensure the highest levels of safety, security and environmental performance".