Utility EDF's Flamanville 3 nuclear reactor in northwest France has been cleared by a group of experts for start-up despite weak spots in its steel, confirming the findings of the ASN nuclear regulator, a source close to the situation told Reuters.

Completion of the third unit at Flamanville, where two reactors have been operating since 1986-87, had been thrown into doubt after the discovery in 2015 of weak spots in the steel prompted an extensive safety review by the ASN.

The ASN report on the reactor, which has yet to be released but a copy of which has been seen by Reuters, concludes that the reactor is fit for service, though it will need to be monitored throughout its lifetime and the lid of the containment vessel will probably need to be replaced in a few years.