Detection of incidents and follow-up by the regulatory bodies

Although France has established a large nuclear program based on PWR type reactors, experience gained up to this are are quite modest. Concept of PWR-900 reactors is based mostly on safety analyses and evaluations done a priori. At the time of their construction and start-up they have been considered as advanced safe systems. No data were available concerning any incidents during operation. The Three Mile Island accident in 1979 has changed the attitude concerning reactor safety. The result is the procedure adopted by Electricite de France for follow-up of incident situations during operation of a number of PWR-900 plants. Standardization of this type of NPPs demands extremely strict standards and control of safety systems. This safety analysis procedure consists of the following: analysis of incidents based on data collected by EDF during operation; every regular annual shutdown of a unit is the subject of detailed analysis; together with the detailed analysis, principal elements of operating experience for the series of PWR units are submitted for analysis to a permanent regulatory body