“Framatome has informed EDF of a deviation from technical standards governing the manufacture of nuclear-reactor components,” EDF said in a statement.
Components currently in use as well as some that had not yet been installed on any sites were affected, EDF said, adding that it had been investigating to ensure all reactors and components were fit for service.
The anomalies concern weldings on some steam generators.
“EDF informed the French nuclear regulatory authority of its initial investigations,” the power group said. “EDF will provide additional information as characterisation work progresses.”
In an unrelated issue, EDF’s project to build a new EPR unit at the Flamanville nuclear station in northern France was recently delayed by about three years due to problems with weldings.
In June regulator ASN said EDF would have to repair eight faulty pipe welds in the secondary main cooling loops before Flamanville-3’s commercial operation.
In August EDF said it had found more than 200 irregularities in materials supplied by the alloys division of the mining and metallurgical company Eramet for its nuclear power plants.
According to ASN the irregularities discovered by EDF required “specific management”, but did not make any of the materials unfit for use.