The French nuclear safety, Autorite de Surete Nucleaire (ASN) has published a list of irregularities so far found in components forged at Areva's Le Creusot facility and used in French NPPs. It said 87 irregularities had been discovered relating to pressure equipment - such as reactor pressure vessels, steam generators and piping in the primary circuit - and packaging for transporting radioactive materials. These include 20 in equipment for the EPR being built at unit 3 of the Flamanville NPP, as well as in steam generators for Gravelines 5, Bugey 4 and Fessenheim 2, and four irregularities in transport packaging.
Areva confirmed on 23 September that its audit at Le Creusot, which began in April 2015, had identified 87 irregularities in reactors in service in the French fleet and that these are being investigated by ASN. However, it added that “the processing of these irregularities undertaken by Areva NP has concluded that the components can remain in service”. Regarding one of the steam generators on Fessenheim 2, a divergence from the forging of the lower shell of the steam generator was found. Areva NP noted ASN’s decision of 18 July, taken as a precautionary measure, to suspend the test certificate of the secondary part of the component.
Areva said Areva NP teams, in coordination with Electricite de France (EDF), are conducting mechanical and chemical analyses, and also undertaking additional testing on sacrificial items with similar characteristics. “Analysis of the documentary anomalies and the detection of methodological discrepancies in the conduct of tensile testing has led Areva NP to expand the audit and conduct a comprehensive quality analysis on its equipment manufacturing sites with the support of an independent expert,” Areva said. In parallel, Areva NP has implemented a quality improvement plan, and has stepped up supervision and oversight of production in progress as well as launching a programme to strengthen its quality culture.
