Second unit could get approval to restart next month, says utility Workers on the refuelling machine at the Hunterston nuclear power station in Scotland. Photo courtesy EDF. France’s state-controlled utility EDF has been given permission to restart its Hunterston B-1 reactor in Scotland “for a limited period of operation’, but will begin decommissioning the facility by January 2022 at the latest, the company said on Thursday.

Hunterston has two advanced gas-cooled reactor units. Hunterston B-1 is a 490-MW GCR that began commercial operation in February 1976 and Hunterston B-2 is a 495-MW GCR that began commercial operation in march 1977.

Together the two units, owned and operated by EDF UK subsidiary EDF Energy, of generate enough electricity to power around 1.7 million homes.

EDF had regulatory approval to operate until March 2023 but both reactors were taken offline in 2018 after cracks were found in the graphite bricks that form the reactor core.

EDF Energy told NucNet that Unit B-2 is offline, but the safety case is with the regulator for assessment and “we have a current return to service date of 17 September, subject to approval”.

EDF said it had received regulatory approval to restart Unit B-1 following a two-year inspection and investment programme. But the company said the plant will move into the defuelling phase no later than 7 January 2022. This is subject to a further inspection in the spring of 2021 and regulatory approval for a final six months of operation.

The Office for Nuclear Regulation said it had given EDF permission for Unit B-1 to return to service for a limited period of operation. The permission is for up to a total of 16.425 terawatt days, approximately six months’ operation.

In 2012 EDF extended the generating life of the station to March 2023, with a proviso of plus or minus two years.

Tom Greatrex, chief executive of the UK’s Nuclear Industry Association, said Hunterston B-1’s restart is a boost for emissions free power, but with the facility’s decommissioning confirmed for January 2022, the urgency of the need to invest in new nuclear is clear. “Without new nuclear power, the UK cannot meet its net zero target,” he said.

““All but one of our current nuclear fleet is due to move to decommissioning this decade, and we need to invest now in the new generation of stations to underpin the UK’s net zero ambitions, while preserving world-class expertise in our home-grown supply chain,” he said.

EDF is building European pressurised water reactors (EPRs) at Hinkley Point C and developing plans for a replica plant at Sizewell C. It also has a minority stake in the Bradwell B project.