Monitoring Irradiation Effects on French PWR (Pressurized Water Reactor) Vessels

摘要

At the end of 1986, thirty-three 900 MW PWR units and nine 1300 MW units are in service. In application of regulations, a program to monitor the effects of irradiation on vessel materials is being performed. It involves the base metal, the heat affected zones (HAZ) and the welds. The contents of embrittling elements are low: 0.08% copper to 0.011% phosphorous maximum, except for the welds of the six oldest vessels, where copper reaches 0.13%. The results obtained to the present are presented in the RTNDT differences. The fluences recorded reach 1.5 /times/ 10 sup 19 n times cm/sup /minus/2/ E > 1 MeV on specimens removed after four years, which corresponds to approximately 12 years of operation, considering the multiplying factor of flux. The average and upper values of difference of the RTNDT are respectively 20/degree/C and 40/degree/C and there is no notable difference between the base metal and the welds. The results obtained are compared with the indications of the various forecasting formulas, specifically with those of a new formula that has been established. 3 refs., 2 figs., 5 tabs. (ERA citation 14:002964)