A group of independent French technical experts unanimously recommended to nuclear regulator ASN earlier this week that state-controlled EDF repair the faulty welds on the 1,600-MW Generation III plant.
ASN’s permanent group of experts has demanded EDF repair eight defective welds in secondary main cooling loop pipes inside the reactor containment, despite EDF objections, the authority said.
According to ASN, the weld faults are “a major obstacle to the exclusion” of a sudden rupture of the main steam-discharge pipes.
ASN said it would announce its decision on the welds “in the near future” following a consultation with its group of experts.
In a statement yesterday EDF said the recommendations made and the solutions suggested by the experts “could impact the commissioning schedule and the cost of construction”. The company said it is continuing discussions with ASN.
A decision on the construction schedule and cost of Flamanville-3 will be made after the publication of ASN’s recommendations, EDF said.
Some French media reports today said the weld problem could delay the plant’s planned commercial operation until 2022.
In January, EDF said it was “actively pursuing” an action plan to rectify problems with welds at Flamanville-3 with hot testing of the plant, previously scheduled to start by the end of 2018, scheduled to begin in the second half of February.
Faulty welds discovered last year forced EDF to delay the start-up date for the plant to the second quarter of 2020 and announce an increase in the cost of the project to €10.5bn and then to €10.9bn. An estimate of the cost in July 2011 was €8bn.
In July 2018, EDF said 53 welds on Flamanville’s secondary circuits would have to be redone, while for another 10 it was confident it could convince regulator ASN that they were fit for service. Another 85 needed no repairs, it said.