Radiological objectives and severe accident mitigation strategy for the generation II PWRs in France in the framework of PLE

In France, EDF is involved in the construction of a first generation III (Gen III) reactor (European Pressurized Reactor - EPR) on Flamanville site next to two PWRs. Plant Life Extension (PLE) of reactors will consequently lead to simultaneous operation of Gen III and Gen II reactors during a long period of time. As a consequence, EDF was requested by the French Nuclear Safety Authority to prepare a PWR life management program including, in addition to an ageing management of Systems, Structures and Components, a consequent reactor safety enhancement program. The objective was stated to EDF by the French Nuclear Safety Authority: 'the safety objectives of the Gen III reactors should be used as a reference for all studies undertaken in the frame of PLE'. One part of the EDF program deals with additional arrangements able to reduce more drastically the consequences of any accident. The relevance, according to IRSN, of the EDF radiological objectives for Design Basis Accidents, of the new EDF objectives for Severe Accidents (SA) and of the EDF potential modifications for SA mitigation are presented. (author)