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PARIS, Oct 18 (Reuters) - France's nuclear watchdog on Tuesday told state utility EDF to conduct safety tests on five nuclear reactors before their scheduled maintenance period, adding potential further pressure to the country's already tight supply situation.
The regulator, ASN, said EDF has confirmed it would carry out the tests on the 5 reactors concerned within three months, earlier than previously planned.
An EDF spokesman said the new schedule did not change its nuclear production outlook for this year. Nevertheless, French forward power prices climbed on the news amid concerns the situation could tighten European electricity supplies during the winter.
ASN asked EDF in June to carry out tests on 18 nuclear reactors in all, 12 of which contain parts manufactured by a Japanese foundry. All 18 are considered to have high carbon concentrations which could weaken their resilience.
EDF has given ASN elements to justify the safety of those 12 with the Japanese-made parts, but following further analysis, the watchdog concluded that further tests were required on these same 12.
ASN said the tests have already been carried out or are currently being carried out on seven of the 12, all during their planned maintenance period.
It wants the tests on the other five brought forward and completed within three months rather than stretching well into Spring of next year as previously planned.
The seven reactors concerned are: Tricastin 1 and 3; Bugey 4, Dampierre 3, Gravelines 2, St Laurent 1 and Civaux 2.
ASN said in a statement that the five reactors still to be tested were: the 1,500 MW Civaux 1 (no maintenance date set); 900 MW Fessenheim 1, scheduled to go offline on Oct. 22; 900 MW Gravelines 4, scheduled for planned outage in April 2017; 900 MW Tricastin 4, scheduled for statutory outage on Oct. 22, and the 900 MW Tricastin 2 scheduled or outage in April 2017. (Reporting by Bate Felix; Editing by Andrew Callus)