Report on the early years of operation of French PWR reactors

Electricite de France (EDF) has put into service 21 pressurized-water reactors (PWR) generating 900 MW(e) per unit, the oldest of which was connected to the grid in April 1977. This paper presents an initial report on the operation of these units which by 1 May 1982 had totalled some 40 reactor-years of operation. In the first part there is an overall report on performance expressed in average annual load factors and in terms of availability during critical hours in winter. These results are compared with the normative values used for reference purposes in investment programmes. The analysis shows that the first 19 units have operated satisfactorily on the whole and highlights the beneficial effects of standardization not only between the units at a given site but also between different sites. Following this evaluation is a discussion of the most significant factors which have influenced the operating results. The behaviour of the principal primary and secondary circuit components is analysed and the lessons learned from the first annual shutdowns are mentioned. Some information is given about the special tools developed for in-service inspection of primary circuit structures. In conclusion, the main elements of the work done by EDF to improve both the performance and the operating conditions of these units are described. (author)