Steel components in the heart of Britain’s most modern nuclear power station are wearing out more quickly than expected, forcing EDF to carry out lengthy unscheduled repairs. The French energy giant is having to keep Sizewell B in Suffolk offline for three months longer than planned to deal with the safety issues. The outage at the plant, capable of producing enough electricity for 2.5 million homes or about 3 per cent of Britain’s needs, will further restrict low-carbon nuclear power supplies amid prolonged shutdowns at older reactors. EDF said it had found wear to some of Sizewell’s stainless steel “thermal sleeves”, which form part of the mechanisms that insert control rods into the reactor core to shut it down. Experience at a reactor in France has shown that extreme wear could eventually result in parts of the thermal sleeves coming loose and obstructing the control rods. EDF is assessing the cause and extent of the wear at Sizewell and how many components need to be replaced before it seeks permission to restart the plant. It insisted the damage was “nowhere near” the stage where it would prevent control rods functioning, and that in any event the reactor could still be shut down safely. EDF has said it will close Hinkley Point B in Somerset and Hunterston B in Scotland permanently by next year, earlier than planned, because of cracks in their graphite cores. It is also considering closing Dungeness B in Kent as soon as this year. The plant was not scheduled to close until 2028 but has been offline since 2018 because of corrosion.
Times 17th May 2021 read more »