An Overview of Severe Accident Approach at EDF—Contribution of R&D Programs

The need for improving knowledge and designing mitigation measures in the field of severe accidents emerged particularly after the Three Mile Island 2 accident. Since the 80s EDF has undertaken, together with its French R&D partners (CEA, IRSN, AREVA), its own R&D programs covering over time nearly all areas related to core melt accidents. EDF also relies on international collaborations with several laboratories, and participates in international programs, either supported by the European Commission or those conducted in the framework of the OECD. This paper gives an overview of the severe accident approach at EDF from an R&D point of view. The phenomena covered are steam explosion, hydrogen combustion, direct containment heating (DCH), slow containment pressurization, basemat penetration. The risks associated with these phenomena in a nuclear power plant and some examples of industrial implementations of mitigation measures, based on engineering and R&D outcomes, are presented.