By David Green
Thursday, November 15, 2012
THE UK nuclear safety watchdog has rejected calls to bring forward an inspection of the pressure vessel “heart” of the Sizewell B nuclear power station following the discovery of cracks in the surface of similar vessels in Belgium.
The flaws, found in July this year in reactors at Doel and Tihange, had not been reported during manufacture or as a result of previous in-service inspections
However, according to the Belgian safety inspectorate there is evidence that the cracks did occur during manufacture in Holland and are not the result of operating stress.
The Sizewell pressure vessel came from a French manufacturer and underwent extensive testing before it was installed on the Suffolk site.
As a result of the discoveries in Belgium the Office for Nuclear Regulation (ONR), the UK safety watchdog, has ordered a check of all the documentation concerning the tests made on the Sizewell B vessel, during manufacture and service.
But anti-nuclear groups, including the Shut Down Sizewell Campaign, have been calling for the next in-service inspection, scheduled for 2015, to be carried out immediately, as a precaution.
The last “in service” inspection was carried out in 2010, when no defects were discovered.
An ONR spokesman said last night the Sizewell B pressure vessel had been constructed and inspected to some of the highest standards in the world.
He added: “There is no reason at this time to believe there are challenges for the current safety justification for Sizewell B.
“However, ONR will maintain an interest in developments in Belgium, and potentially elsewhere, and assess this information when considering whether any regulatory action is necessary.”
Charles Barnett, chairman of the Shut Down Sizewell Campaign, said the collapse of the Sizewell B pressure vessel would be catastrophic in terms of a radiation release.
He said that, as a precaution, the in-service inspection should be brought forward and carried out as soon as possible.
The latest report from the ONR did not address the group’s concerns, he said.
“Frankly, this new document in no way dispels our fears since it does not provide any firm evidence that the Sizewell B pressure vessel is free from cracking,” Mr Barnett added.
EDF Energy was invited to comment but did not respond.