French state-controlled utility Electricite de France (EdF) previously notified the country's nuclear safety authority, ASN, of deviations in the manufacture of some steam-generator welds for its nuclear reactors. The "deviation from technical standards" involved the “detensioning heat treatment on the welds” (stress relief).

EdF has since said that this condition does not adversely affect the components' fitness for service and no immediate action is required. Sixteen steam generators installed on six operating reactor units are involved.