Sizewell B: Safety expert rejects calls to bring forward N-plant reactor tests following Belgian discoveries
15:00 29 December 2012
A SENIOR nuclear safety official has firmly rejected a call for routine tests on the pressure vessel “heart” of the Sizewell B reactor to be brought forward following the discovery of cracks in similar vessels in two Belgian plants earlier this year.
The Shut Down Sizewell Campaign believes an inspection scheduled at the Suffolk power station during a planned maintenance shutdown, known as an outage, in 2015, should be carried out now as a matter of urgency.
But, in a letter to the group, the Office for Nuclear Regulation’s superintending inspector, Graham Heys, says that given the thorough testing of the Sizewell B vessel during and after manufacture he does not consider it “proportionate” to bring the date forward.
The pressure vessels at Doel and Tihange in Belgium came from a different manufacturer from that used for Sizewell B for which, according to the ONR, superior standards were attained.
As a precaution the ONR has asked EDF Energy, which owns and operates Sizewell B, to check all documentation relating to tests carried out on the pressure vessel.
Mr Heys says in his letter to the Suffolk anti-nuclear group: “Given the absence of flaws observed in the investigations to date, and quality controls in place at manufacture to prevent occurrence, I consider it highly unlikely that the extensive defectiveness observed at Doel 3 will be observed at Sizewell B.”
He adds: “I am therefore content for Sizewell B to continue to operate subject to satisfactory periodic safety reviews being carried out and satisfactory results from routine maintenance, inspection and testing that continue to support the agreed plant safety case.
“Given the confidence in build quality at Sizewell B, the depth and breadth of the manufacturing records and the improved inspection routines used at Sizewell B, compared with Doel 3, we do not consider it necessary to bring inspections forward ahead of the 2015 outage.”
Charles Barnett, chairman of the Shut Down Sizewell Campaign, said the ONR’s stance was “totally unacceptable” in the light of the Belgian discoveries.
“We still await up to date evidence that cracks have not developed in the Sizewell B pressure vessel and, in line with the precautionary principle, an early inspection should take place,” he said.
The last in-service inspection of the Sizewell B pressure vessel took place in 2010. No defects were found.
EDF is due to report to the ONR on the documentation check by the end of the year.
A company spokesman said: “The report is in the final stages of being completed and will be submitted on the timescale agreed with the ONR.”