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EDF extends outage at British reactor where cracks found

LONDON, Nov 22 (Reuters) - EDF Energy has extended an outage at its Hunterston B-7 nuclear reactor in Britain, offline since March when cracks were found in its core, until Feb. 21, it said in a market update.

The cracks were found at the reactor, which can produce enough electricity to power more than 800,000 homes, during a routine inspection.

Hunterston B-7 was initially scheduled to return to service on Nov. 17, later pushed back until Dec (Shanghai: 600875.SS - news) . 18. EDF Energy said it had extended the outage to prepare a safety case needed for Britain's nuclear regulator to allow the unit to restart.

"We are preparing to present a safety case for (the) return to service of Reactor 3 (turbine generator 7) to the regulator, the ONR (Office for Nuclear Regulation)," a spokeswoman for EDF (Swiss: EDF.SW - news) Energy, the UK arm of France's EDF (Paris: FR0010242511 - news) , said via email.

EDF Energy said a safety case has been submitted to the ONR for the Hunterston B-8 unit, which has been offline since October, but an outage at that reactor has been extended until Jan. 14 to allow the regulator time to review the case.

"We have updated (the outages) to reflect the further time needed for the preparation and assessment of the safety cases," the spokeswoman said.

EDF Energy's 15 nuclear reactors provide around 20 percent of Britain's electricity.

However almost half of this capacity, including Hunterston, which is over 40 years old, is due to go offline by 2025. (Reporting by Susanna Twidale; Editing by Jan Harvey)