UPDATE 1-FirstEnergy Pa. Beaver Vly 2 reactor in hot shutdown

(Updates with trader comments)

NEW YORK Nov 24 (Reuters) - FirstEnergy Corp's (FE.N) 846-megawatt Unit 2 at the Beaver Valley nuclear power station in Pennsylvania was in hot shutdown on Nov. 24, the company told the U.S. Nuclear Regulatory Commission in a report.

The unit shut for refueling and maintenance by Oct. 12.

The company made the report due to an unidentified leakage greater than 25 gallons per minute in the reactor coolant system. The company declared an unusual event, the lowest of the NRC's four emergency classifications, due to the leak.

Electricity traders guessed the unit had been close to exiting the refueling outage at the time of the leak.

The traders also noted the NRC would likely take this event seriously because the residual heat removal system was one of the last lines of defense to keep the core cool.

The leak was into the pressurizer relief tank during the shutdown of one of the trains in the residual heat removal system. The company stopped the leak by isolating the train.

The company said in the report the containment was closed and the leak did not cause any radiation to be released.

The unit last shut for refueling from about April 14-May 27, 2008. It is on an 18-month refueling cycle. (Reporting by Scott DiSavino; Editing by John Picinich) ((scott.disavino@thomsonreuters.com; +1 646 223 6072; Reuters Messaging: scott.disavino.reuters.com@reuters.net)) ((For help: Click "Contact Us" in your desk top, click here [HELP] or call 1-800-738-8377 for Reuters Products and +1-888-463-3383 for Thomson products; For client training: training.americas@thomsonreuters.com; +1 646-223-5546))