Diagnosis and prognosis method for severe accident situation as applied by EDF

For the last few years EDF, in conjunction with IPSN/CEA, has been developing an approach, intended for specialists of its emergency teams, which formulates in real time an operational synthesis for the case of an accident on a PWR. This synthesis includes a diagnosis and a prognosis of the evolution during 24 hours of the state of the reactor and an evaluation of the radioactive releases to the environment. In summary: Facing the challenge posed by the prediction in real time of the evolution and consequences of a reactor accident, EDF is engaged in the establishment of an operational approach which, although very modest in relation to the complexity of the problem, improves the understanding of the overall situation for the emergency teams. This approach will be improved as a function of, the experiences reported by the emergency teams, the increase in knowledge and the development of new tools