Members of GMB, the union for nuclear workers, working at Sellafield Ltd in Cumbria have voted for strike action in a dispute over pay.
Following a three week ballot, a total of 76% of ballot papers are in support of strike action.
This came after the company ignored requests for further talks and said it would put in place a below-inflation pay offer.
Sellafield offered a 1.5% pay offer in June which was rejected by 88% of GMB members on site during a consultative ballot.
The RPI inflation rate is currently 3.6%.
The Unite union is also balloting its 2,000 members at Sellafield.
Last year Sellafield workers accepted just 0.25% extra pay against annual RPI inflation for 2016 of 1.8%.
It was accepted to stop Sellafield management from cutting the pay of apprentices.
Two thirds of Sellafield workers will also have to pay an extra 2 to 6% on their pensions contributions from next year.
This is part of government led changes to the pensions of nuclear workers.
GMB's Sellafield Strike Committee will meet later this week to decide on the date for the first strike, which is set to be sometime this month:
In a statement, Sellafield Ltd. said: