France’s Nuclear Safety Authority (Autorite de Surete Nucleaire - ASN) said in a statement on 3 October that faulty weldings at unit 3 of the Flamanville nuclear plant in Normandy may require more repairs than originally estimated and that EDF will have to review materials on the site.
In July, problems with the weldings led to EDF again delaying startup of the EPR reactor to the second quarter of 2020, pushing its cost estimate up to three times the original budget. EDF said at the time that 53 welds on Flamanville 3’s secondary circuit would have to be repaired, it was confident that it could convince the ASN that ten more were fit for service, and 85 needed no repairs.
However, ASN has said that a programme of major tests would be necessary to verify whether eight of the weldings are fit for service. ASN said that should this not be the case, it invites EDF to start preparation for possible repair work. ASN added that it would start an investigation of EDF’s proposals and criticised the way EDF had handled the welding problems.
“The problems with the weldings show that EDF has failed to properly oversee certain activities on the Flamanville reactor construction site,” the regulator said and demanded that EDF broaden the quality review of materials installed on the reactor.
ASN noted that the first problems had been identified in July 2015, and said management of the situation by EDF had been inadequate. “Therefore ASN demands that EDF proceed to a thorough analysis of the dysfunctions at EDF and its suppliers,” it said. EDF must also explain why it informed ASN so late, at the start of the 2017.
Three other EPRs under construction in China (Taishan 1&2) and Finland (Olkiluoto 3) have also suffered long delays (five years in China and 10 years in Finland) and cost overruns . EDF is building two similar EPR reactors at Hinkley Point in the UK.