EDF has said it will standardise corrosion repair works at its NPPs in order to get them back in service as soon as possible. Corrosion problems were first detected over a year ago, sparking a campaign of inspections and repair works, with 32 of France’s 56 reactors simultaneously shut down in the summer. EDF has admitted that repairs required to correct corrosion problems were more extensive than expected. Currently 26 reactors are shut down: 15 for stress corrosion problems, and 11 for maintenance. EDF said strikes in October around wages had led to delays in maintenance work.

"We are in a phase where it is industrialisation and standardisation which is the key to control the impact (of corrosion)," says Regis Clement, deputy director of nuclear production at EDF. The teams undertaking repairs will have to follow a process that is reproduced from reactor to reactor. “This will make it more efficient and gradually reduce the duration of construction sites", he said, adding that EDF now hoped to move forward with a strategy for handling corrosions.

Separately, Clement confirmed that a leak detected recently at unit 1 of the Civaux NPP was not due to welding but to problems with a system put in place to test the waterproofing of the primary circuit. The 1,500MWe reactor has been shut since August 2021 for scheduled 10-year maintenance. While Civaux 1 is affected by corrosion, EDF said the leak was not linked to that problem.

Image: The Civaux nuclear power plant (courtesy of EDF)