Complementary investigation program undertaken at EDF nuclear power plants during the second ten-yearly outage

The Complementary Investigation Program (CIP) has been established to verify the absence of degradation regarding points not included in the actual BPMP.The CIP has been applied to the following 7 main safety systems: reactor coolant system; main steam system; main feedwater system; residual heat removal system; safety injection system; component cooling system. PSA have been performed to obtain the main points to be controlled. Because of the large number of points (2400 concerning pipes and vessels), they have been distributed to several nuclear power plants of the same standardized plant series and providing similar systems. The degradation mechanism of interest were internal/external corrosion, flow accelerated corrosion, cavitation, thermal and vibration fatigue. The CIP demonstrates the accuracy of actual BPMP and verifies the good material condition after 20 years of service