NEW cracks have been discovered in one of Scotland’s ageing nuclear reactors, raising radiation safety fears and resulting in a prolonged shutdown, the Sunday Herald can reveal.
Checks have detected fresh cracks in the graphite core of a reactor at Hunterston B in North Ayrshire. The reactor was taken offline on March 9, but is not now due to restart until May 1 at the earliest, more than a month later than originally planned.
The integrity of the thousands of graphite blocks that make up the reactor core is vital to nuclear safety. They ensure that the reactor can be cooled and safely shut down in an emergency.
But bombardment by intense radiation over decades causes the blocks to start cracking. If they fail, experts say, nuclear fuel could overheat, melt down and leak radioactivity in a major accident.
Both the ONR and EDF told the Sunday Herald that new cracks had been found at Hunterston reactor number three during inspections in recent weeks, but they wouldn’t say how many, or how significant they were.
Hunterston reactor three, which has been running since 1976, is one of the oldest of its kind. It’s where “graphite defects are most advanced” and hence has more inspections than other reactors, said the EDF spokeswoman.
But Pete Roche, a nuclear critic and consultant in Edinburgh, warned that EDF’s optimism that the reactor will restart could be misplaced. “Cracks could prevent control rods from being inserted causing the nuclear fuel to overheat, potentially resulting in a nuclear accident,” he said.
It was “all a bit of a gamble”, he argued. “Hunterston is already 42 years old – when it was only expected to operate for 30 or 35 years. It is clearly time to say goodbye to reactor three.”
According to Rita Holmes, a local resident who chairs the Hunterston site stakeholder group, people were worried. “The local communities are unhappy that the reactor has any cracks, and certainly not happy that one with a growing number of cracks could be allowed to continue generation,” she said.
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