EDF said on 26 July that unit 3 at the Flamanville nuclear plant in northern France will not be ready before the end of 2022, pushing back the date by three years becasu of ongoing problems with weldings.
The French Nuclear Safety Authority (ASN) in June confirmed recommendations by its technical arm that EDF, “rather than trying to justify that the weldings are fit for service in their current state, should proceed to repair the weldings”. ASN’s permanent group of experts asked EDF to repair eight defective welds in secondary main cooling loop pipes inside the reactor containment. It said the weld faults are “a major obstacle" to the exclusion of a sudden rupture of the main steam-discharge pipes.
Last summer EDF said that the welding problems had increased the Flamanville 3 reactor cost estimate by €400 million to €10.9bn ($12.3bn), from an initial budget of €3bn, and had delayed startup to mid-2020. In July 2018, EDF said 53 welds on the secondary circuits would have to be redone, but that it was confident it could convince ASN that ten others were fit for service. Another 85 needed no repairs, it said. However, in January ASN questioned the quality of eight weldings on pipes between the reactor building and the turbine building.
EDF said three scenarios for carrying out the repairs were being considered, with a detailed schedule expected in the coming months.
The issue with the welding follows earlier problems related to excessive carbon concentrations in the components manufactured at Areva’s Creusot Forge, which weakened the steel in the cover for the reactor vessel.
Construction of the Flamanville 3 EPR began in 2007 and was initially due for completion in 2012.