Safety fears after new cracks found at nuclear station
CALLS have been made to close the Hunterston nuclear power station after fresh cracks were found in the Ayrshire plant’s core.
Three graphite bricks in one of the two nuclear reactors have cracked since October last year, when two more were discovered.
Experts have warned that potentially serious safety issues may be caused by the ‘unreliable’ core. The blocks, along with control rods, help keep the speed of the nuclear reaction within acceptable limits.
Operator EDF Energy insists there are ‘absolutely no safety implications’ from the cracks.
However, independent nuclear energy consultant John Large said: ‘There are quite serious nuclear safety implications under certain fault conditions’ and that the cracking was due to the age of the reactor.
He added: ‘There is little to be done to alleviate it. The cracking results in a loss of residual strength of the overall graphite moderator core into which the nuclear fuel is inserted. The industry has known about this problem since before 2006.
‘This cracking is one of several clear indicators that the nuclear reactors at Hunterston B have reached, if not exceeded, their working and safe lives. These two reactors should be permanently shut down without further ado.’
The 39-year-old station was due to be decommissioned next year but its life was extended to 2023 after an evaluation of the plant three years ago.
EDF said the projected closure date would not be affected by the latest evidence of ‘keyway root cracking’.
A spokesman for the French company said the cracking was anticipated as the station ages, and that the plant would still meet regulations if 30 per cent of its 6,000 graphite bricks were cracked.
Station director Colin Weir said: ‘Nuclear safety drives everything we do. This means we work within very large safety margins.
‘The level of cracking which is considered reasonable is far
‘Reactors should be shut down’
below anything which would affect the reactor’s safe operation.
‘It is accepted by our regulators and materials experts that cracks will occur in some of the bricks.
‘The observations were anticipated and in line with our understanding, so our view of the best estimate lifetime planning date of 2023 has not changed.’
Lang Banks, director of World Wildlife Fund Scotland, said: ‘More cracks in the country’s ageing nuclear power stations underscores why we’re right to be taking steps to harness cleaner, safer forms of energy.’
Energy Minister Fergus Ewing said: ‘The reactor operator has provided assurances that there are no immediate safety implications.
‘At the same time, this development does illustrate that Scotland’s nuclear facilities have a limited lifespan and we need to put in place longerterm energy alternatives.’