* ASN again delays ruling on safety of Flamanville reactor
* Postpones ruling to “autumn” from “end of summer”
* Will issue provisional ruling in July, then seek input (Adds new ASN statement)
By Geert De Clercq
PARIS, May 30 (Reuters) - French nuclear regulator ASN said on Tuesday it will “probably” issue a final ruling in the autumn on whether the reactor that utility EDF is building in Flamanville is safe for use, in the latest delay in the process.
The ASN said in 2015 it had discovered excessive carbon concentrations in the cover and bottom of the Flamanville reactor vessel, which can weaken the mechanical resilience of the steel and its ability to resist the spreading of cracks.
Since then, Areva, which designed the EPR reactor, EDF and the ASN have been testing whether weak spots could jeopardise the safety of the reactor.
The regulator’s green light about the reactor vessel is crucial for EDF and Areva, as European Union antitrust authorities have made it a precondition for their approval of EDF’s planned takeover of Areva’s reactor unit.
The ASN has repeatedly postponed deadlines for ruling on the safety of reactor vessel.
And in what will be another delay, an ASN spokesman said in an email that the regulator now expected a “firm position probably in (the) autumn”.
The ASN’s definitive position would probably come at the start of the autumn, he told Reuters by telephone.
In October 2015 the ASN said a ruling was due “soon”. In January 2016, it pushed back the decision to the end of 2016, and in January, ASN chief Pierre-Franck Chevet said a ruling was due by the middle of this year. In March, the ASN again delayed this to “the end of summer”.
Earlier on Tuesday, the ASN said it expected to receive technical reports about the reactor vessel by the end of next month. It will analyse these and then draft a provisional ruling on Flamanville, which will be made public in early to mid-July. It will then invite feedback on this ruling from the public, civil society, local authorities and the companies involved.
With the Flamanville reactor vessel welded in place in 2013 and covered by thousands of tonnes of concrete since then, taking out the vessel would delay the reactor startup by several years and cost billions of euros.
EDF has repeatedly said it is confident the ASN will find the vessel fit for operation.
French news agency AFP on Tuesday quoted an ASN official in Normandy as telling a local information meeting that ASN would rule early July on the vessel.
The Flamanville reactor is years behind schedule and billions over budget, but EDF CEO Jean-Bernard Levy said this month EDF plans to load fuel in the reactor before end-2018.
Construction in Flamanville started in 2007 and the plant was supposed to go online in 2012, but EDF has announced new delays and cost overruns every few years. The company said in 2015 the reactor would cost 10.5 billion euros ($12 billion), up from an initial budget of 3 billion. ($1 = 0.8948 euros) (Editing by Mark Potter/Alexander Smith)