Some primary bottom heads of steam generators installed at 18 of EDF’s 58 reactors in France could have a significant carbon concentration similar to the anomaly found on the reactor pressure vessel at the company’s Flamanville-3 EPR under construction in northern France, French nuclear safety authority ASN said.
Areva, EDF and ASN reported in April 2015 that chemical tests Areva performed in 2012 on steel similar to that used in the reactor vessel top and bottom heads at Flamanville-3 showed a high carbon content in the vessel heads, which can reduce the ability for the component to withstand crack propagation.
The discovery of that anomaly led ASN and EDF to investigate whether it is also present on other components in operation at existing reactors, ASN said. The bottom heads at the 18 reactors were manufactured either by Areva’s Le Creusot forge facility or by Japan Casting and Forging Corporation in Japan, ASN said. ASN said ongoing analyses on reactor vessels, pressurisers and steam generators could show that other forged components may also be affected by the anomaly. The list of reactors that might be affected is online.