The study indicates that a restart could cause a microcrack to expand and lead to possible failure of the reactor and would have catastrophic consequences, in the vicinity of a densely populated areas.
The reactors in question are the Doel-3 plant is situated close to the northern city of Antwerp, and Tihange which is near Liege.
If a melted reactor core could cause a containment failure and severe radioactive releases to the environment, the study concludes.
The paper ‘Flawed reactor pressure vessels in Belgian nuclear plants Doel-3 and Tihange-2’ was written by Ilse Tweer, a consultant who has previously contributed to reports by the Austrian Nuclear Safety Advisory Board.
Belgium’s nuclear safety authority, the FANC, is expected to give the two plants a clean bill of health in a report to the Belgian government. But no official decision on their future has yet been taken.
The 1970s-era plants, which are owned by the Belgian power utility Electrabel, were closed in August 2012 after the country’s nuclear regulator highlighed roblems in Doel-3’s construction and a large number of non-hazardous defects.
The new report claims to have found indications of radiation embrittlement of the plant’s steel reactor pressure vessel, in an examination that they say was not used in the ‘stress tests’ imposed by the European Commission after the Fukushima disaster.
“If you have these problems in Belgium, all the other reactors (in Europe) should be checked for the same defects,” the Belgian Green MP Kristof Calvo told a press conference at the European Parliament yesterday (10 January).
Anti-nuclear campaigners are meanwhile planning a demonstration at the Tihange plant.