French propose new 'hard core' approach to nuclear safety

Paris (Platts)--7Nov2011/825 am EST/1325 GMT

France's IRSN institute of radiological protection and nuclear safety is proposing a new approach to ensuring the safety of nuclear installations based on a relatively simple set of measures designed to prevent severe accidents from becoming catastrophic ones.

The method, worked out in the context of France's national post-Fukushima "complementary safety evaluations," or ECS, centers on definition of a set of "hard core" systems, structures and components that are crucial to controlling an accident situation and preventing the spread of radioactivity into the environment, IRSN officials told journalists in Paris Monday.

Martial Jorel, head of IRSN's reactor safety department, said that with this approach a limited number of SSCs can be qualified to resist external events much more severe than those taken into account in the entire plant's design basis. Even if there were an earthquake or flood greater than most of the plant's systems are designed to resist, he said, the more "robust" equipment would be able to prevent a catastrophic accident such as the events that destroyed Japan's Fukushima I nuclear power plant on March 11.

Jacques Repussard, IRSN director general, said the analysis of French nuclear installations in light of the Fukushima events revealed that the threats to reactor safety of external events like earthquakes or flooding had not been taken into account as seriously as had internal accident initiators.

Repussard said that the new approach, if adopted, would require backfitting or replacement of some systems, such as the filtered containment vents at French reactors which are not currently seismically qualified.

Diesel generators and emergency fuel and water tanks could also be made robust against external events, the officials said.

By targeting certain SSCs, operators would not have to attempt seismic backfitting and requalification of hundreds of components in an entire plant, which would be prohibitively expensive if it could be done at all, Jorel said.

He added that EDF, in initial technical discussions, had expressed interest in using the new "hard core" method, as had other French nuclear operators like Areva, the atomic energy commission CEA, and the Institute Laue Langevin, which operates the High-Flux Reactor in Grenoble.

--Ann MacLachlan, ann_maclachlan@platts.com

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