The defueling of the two plants, Hinkley Point B-1 and Hinkley Point B-2, will begin no later than July 2022, according to the French energy group.
The shutdown was scheduled for 2023, but cracks were discovered in the graphite core of the reactor. According to the International Atomic Energy Agency, Hinkley Point B-1 began commercial operation in October 1978 and Hinkley Point B-2 in September 1976.
Matt Sykes, the managing director of EDF Generation, said an inspection of Hinkley Point B’s graphite blocks revealed they were “in exactly the sort of condition” expected after 40 years of generating electricity. He said running a nuclear power plant this efficiently for over 40 years leads to changes in the reactors.
“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,” Mr Sykes said.
The power station, which has been Britain’s most productive and whose operational life was extended by seven years to 2023, is offline for further inspections and is scheduled to return to service next year, pending approval from the nuclear regulator. The announcement means the site will stop generating electricity just a few months ahead of the 2023 extension and over 15 years longer than originally planned in the 1960s
Tom Greatrex, chief executive of the UK’s Nuclear Industry Association, said the Hinkley Point B shutdown was “a reminder of the urgency of investing in new nuclear capacity to hit net zero”.
EDF had expected the shutdown to take place after the start-up of two EPR plants neighbouring Hinkley Point C, the first new nuclear facility being built in the UK in a generation, which was originally due to begin generating electricity before 2020.
However, the scheduled start date has been delayed to between 2025 and 2026 owing to slow progress in agreeing with the government a guaranteed price for the electricity produced.
Mr Greatrex said: “Hinkley Point B has produced more clean electricity and saved more emissions, 105m tonnes, than any other single power station in British history. It can only be replaced by new nuclear stations that produce the same reliable, always-on, emissions-free power that Hinkley has provided for more than 40 years.”
Prime minister Boris Johnson’s 10-point climate plan, which was revealed on Tuesday, promised to advance large-scale nuclear projects and the developments of advanced reactors with a £525m support package.
But the plan failed to approve EDF Energy’s planned followup to the Hinkley Point C project at Sizewell C, which the company hopes to build alongside China’s CGN.
The NIA said it hoped the government would provide a clear path towards new nuclear capacity in an energy white paper, which is expected before Christmas.