PARIS (Reuters) - French utility EDF (EDF.PA) can continue operating nuclear reactors that have generators with defective welding, the country’s ASN nuclear regulator said in a statement on Thursday, easing fears of potentially tight power supplies during winter.
The watchdog said it carried out two onsite inspections, while EDF and components maker Framatome provided it with evidence that the integrity of the equipment had not been compromised.
“On that basis, ASN considers that the reactors concerned can continue to operate as they are,” it said in the statement.
ASN’s head Bernard Doroszczuk told Les Echos newspaper earlier on Thursday that: “In view of the analysis we have carried out since the beginning of September ... we believe there is no need to halt the reactors equipped with the steam generators affected by defective welds.”
He said the investigation was ongoing and could last up to two years.
In the statement, ASN said it had asked EDF to carry out tests during scheduled shutdowns of the reactors up to the summer of 2020 to confirm the safety assumptions.
An EDF spokesman had said the company welcomed the remarks from the head of the regulatory agency but made no immediate comment after the formal ruling was announced.
EDF shares were among the top gainers on the Paris bourse on Thursday and were up 2% by 1502 GMT.
Atomic power from France’s 58 nuclear reactors operated by EDF covers around 75% of the country’s electricity needs.
Doroszczuk said the regulator had not yet made a ruling on generators that will be installed at EDF’s Flamanville 3 EPR nuclear reactor under construction in northern France.
EDF and Framatome “reacted quickly when the defects were detected, which has not always been the case in the past”, Doroszczuk said, adding that EDF seemed to have learned some useful lessons.
EDF said in September that the problems were identified in reactors 3 and 4 at its Blayais plant, reactor 3 at Bugey, reactor 2 at Fessenheim, reactor 4 at Dampierre-en-Burly and reactor 2 at Paluel.
In the autumn of 2016, the regulator ordered EDF to halt up to a third of its reactors for weeks for safety checks and repairs following separate problems with components.
Reporting by Bate Felix; Editing by Sudip Kar-Gupta, Edwina Gibbs, Dale Hudson, Kirsten Donovan