* ASN gives generic green light for EDF reactors
* Extra tests needed, EDF says will be done quickly
* French forward power prices tumble, EDF post gains
(Adds details, quotes, background and shares)
By Geert De Clercq and Bate Felix
PARIS, Dec 5 French winter electricity supply
worries could ease after nuclear safety regulator ASN gave
approval in principle on Monday for EDF to restart some
nuclear reactors involved in a safety investigation.
ASN said it agreed with EDF that some nuclear reactors whose
steam generators have high carbon concentrations could be
restarted, although the utility would have to carry out extra
tests and the restart of each individual reactor would be
subject to ASN approval.
ASN is checking 12 of the state-controlled utility's
reactors after raising concerns that certain steam generator
channel heads could contain a zone with a high carbon
concentration, which could weaken the resilience of the steel
and its ability to resist the spreading of cracks.
The checks have delayed the restart of several reactors,
forcing EDF to prolong their outage periods and raising fears
that France, which depends on its 58 nuclear reactors for 75
percent of its electricity needs, could face a tight supply this
French and European power prices have hit new highs over the
past weeks due to the tight supply fears.
ASN's comments sent the French power price for January
delivery down 19.3 percent to 65 euros ($70) a megawatt hour
(MWh) by 1642 GMT on Monday. February and March
prices also fell and first quarter was off 17 percent.
A London-based power trader said ASN's statement opened the
door for an early restart of some reactors and also suggested it
was ruling out a complete shutdown or costly replacement of the
"Today, we are able to give rather positive news," ASN head
Pierre-Franck Chevet told Reuters after the news conference.
"The restart of the EDF reactors could happen quickly, it is
in the hands of EDF," Chevet said, adding that ASN estimates
that EDF could get its documents ready for each plant in about
two weeks per reactor.
Seven of the reactors are expected to resume production on
A spokeswoman for EDF said the company will work quickly to
carry out the extra tests on the reactors involved and provide
the additional information to ASN. It is ready to restart the
reactors once it receives the green light from the watchdog, the
EDF's shares rose sharply after ASN's announcement and had
gained 2.28 percent by 1703 GMT, outperforming the European
utilities index, which was down nearly 1 percent.
"There is evidently some relief in the market to what ASN
has just said. But there is still fragility in the supply
situation in France," a European power trader said.
In a separate statement, French nuclear safety institute
IRSN, which provides expertise to ASN on the investigation, said
that tests had shown no risk of rupture of steam generators on
900-megawatt reactors except for Bugey 4, Fessenheim 1 and
"Our investigations have shown that there are no risks of a
brutal rupture," IRSN's deputy director Thierry Charles, told
($1 = 0.9326 euros)
(Additional reporting by Nina Chestney in London; Editing by
Adrian Croft and Susan Fenton)