Hinkley Point B nuclear power station near Burnham-On-Sea will be closed down within the next two years, EDF has announced this week.
The energy firm says the power station will be decommissioned no later than July 2022.
The site began generating electricity in 1976 and station director Peter Evans says he is “proud of what we have achieved”.
The power station employs about 500 full-time staff and 200 contractors who are in consultation over their future.
Once Hinkley Point B stops generating power, EDF will begin defueling the station, which is the first stage of nuclear decommissioning.
EDF says it is talking to staff about their futures, saying some will choose to retire over next couple of years, with others supported to stay with the company, or move into another job or training.
Matt Sykes, managing director of EDF Generation, said: “As a responsible operator we feel it is now the right thing to do to give clarity to our staff, partners and community about the future life of the station.”