NEW YORK - FirstEnergy Corp shut the 1,231-megawatt Perry nuclear power station in Ohio on Oct. 16 after it exited an outage begun on Oct. 15, the company told the U.S. Nuclear Regulatory Commission in a couple of reports.

The company shut the unit on Oct. 15 due to an inoperable emergency service water system.

FirstEnergy restarted the reactor and brought it up to 30 percent by early Friday before shutting it on Oct. 16 due to a reactor recirculation pump trip.

The company did not say in the reports when the unit would again return to service. Electricity traders guessed it would return within a week.

The Perry station, which entered service in 1987, is located in North Perry in Lake County about 35 miles northeast of Cleveland.

One MW powers about 800 homes in Ohio.

FirstEnergy plans to file with the NRC in August 2013 to renew the reactor's original 40-year operating license for another 20 years.

FirstEnergy, of Akron, Ohio, owns and operates nearly 14,000 MW of generating capacity, markets energy commodities, and transmits and distributes electricity to about 4.5 million customers in Ohio, Pennsylvania and New Jersey. (Reporting by Scott DiSavino; Editing by John Picinich)