June 18 2013 Latest news:
By David Green
Saturday, September 8, 2012
NUCLEAR safety inspectors are calling for a re-examination of tests on the pressure vessel “heart” of the Sizewell B reactor following the discovery of cracks in a similar reactor in Belgium.
Inspectors in various countries have ordered a series of safety checks in light of the Belgian discovery because collapse of a nuclear pressure vessel could lead to catastrophe.
The Sizewell B vessel was manufactured in France in the 1980s and was exhaustively tested before and after delivery.
The vessel involved in the safety scare at Doel in Belgium – the first of a series of that country’s nuclear plants to be subjected to new tests – was not from the same manufacturer.
Cracks found in the welded steel vessel have been identified as existing after manufacture, not as a result of operation. But the flaws were not discovered at the time, partly due to more sophisticated modern testing equipment.
As a precaution in the UK, the Office for Nuclear Regulation (ONR) is now calling on EDF Energy to re-examine data on all the tests that were carried out on the Sizewell B vessel before and after it was installed.
In addition, it has called for checks to be made on all the results of routine inspections carried out since the reactor went into operation in 1994.
Paul Smith, the ONR’s Sizewell B inspector, told a meeting of the Sizewell Stakeholder Group that EDF was also being asked to look at its procedures for inspecting the B station’s pressure vessel.
“However, the flaws found in Belgium originated during manufacture, not as a result of operation,” he said.
Mr Smith was among those who attended an international conference in Brussels on August 16 aimed at informing the safety watchdogs of countries with pressurised water reactor nuclear power stations what was happening in Belgium.
Sizewell B is the only pressurised water reactor so far built in the UK, although two further such reactors are planned to comprise Sizewell C.