EDF’s Hunterston B nuclear power plant has has the go-ahead from the Office for Nuclear Regulation to restart for a short period before closing for good.
Both reactors won permission for a period of around six months. The remaining life has been expressed as the amount of power that each reactor can producd – 16.7 terawatt days for Reactor 3 and 16.52 terawatt days for Reactor 4 – because the major reason for closure is aging of graphite blocs, which surround the fuel and control rods in this type of reactor. The graphite is a structural elelment if the reactor core and control rods have to be able to pass through it without obstruction to shut down the reactor. As the graphite is irradiated during operation the grophite blocks crack and distort, and that ultimately puts both control rod movement and heat transport at risk. ONR said, “We are satisfied that Reactors 3 and 4 at Hunterston B are safe to operate for the specified periods above, and that they can be safely shutdown (including in a significant seismic event) if required.”
Hunterston B started generating in 1976. When EDF acquired the power station it was expected to end generation in 2016. In 2012, EDF announced that the estimated end of generation would be 2021-2025, with the most likley date in 2023. On 27 August 2020, EDF said generation would end by 7 January 2022.
Further reading
EDF moving out of gas, out of coal … and may be out of Dungeness this year