Les cahiers de l’ASN #02 - Conditions for the continued operation of EDF’s 900MWe reactors

THE ASN RESOLUTION The additional means planned by EDF shall constitute major improvements in the safety of the fuel storage pools. These means, most of which are part of the “hardened safety core”, shall greatly reduce the risk of the pool water level dropping and exposing the fuel assemblies and, in the majority of the situations considered, shall enable a final post-accident state to be reached without pool boiling. For situations in which such a state could not be reached with the means considered in the safety case, EDF must define measures to improve the prevention of these situations , and post-accident management measures that ultimately enable such as state to be reached. The results of the studies conducted by EDF and the planned modifications, supplemented by the ASN requests, will enable the targeted objectives of this safety review to be met. EDF has planned to put in place during the 10-yearly outage a water make-up system from a diversified ultimate water source and a complementary cooling system for the fuel storage pool. What measures are planned by EDF? EDF has widened the scope of the accident situations studied for the fuel storage pool. These studies have led to modification proposals , such as the addition of fire protection screens or automatic systems to close certain valves should the pool water level drop. Lastly, EDF has demonstrated that the accidental crash of a light aircraft does not call into question the cooling of the fuel assemblies in the storage pool. Conditions for the continued operation of EDF’s 900MWe reactors • 15