FirstEnergy spokesman Todd Schneider said that during a routine inspection in September, the company found a small spot of corrosion on the reactor head at the Beaver Valley Nuclear Power Station in Shippingport, Pa.

Schneider said the company believes the corrosion was caused by a flange leak in 1989, and that it never posed a safety threat. The damage was repaired and reported to the Nuclear Regulatory Commission, Schneider said.

FirstEnergy had shut down its Davis-Besse Nuclear Power Station near Oak Harbor Feb. 16 for a routine refueling and maintenance check. During the outage, workers found corrosion in the reactor head apparently caused by boric acid deposits.

The company found a 4-inch by 5-inch by 6 1/2-inch deep hole in the Davis-Besse reactor, Schneider said. The corrosion at the Beaver Valley reactor was less than1/8 inch deep.

A preliminary report shows a crack in a nozzle in the reactor head at Davis-Besse Nuclear Power Station began at least nine years ago.

The report, posted Monday on the Nuclear Regulatory Commission Web site, was developed by a team of experts enlisted by Davis-Besse officials to investigate the cause of corrosion.

Currently, a team of about 50 experts have been recruited from around the world to come up with a viable solution, and that solution could be cutting out the damaged area and welding a heavy piece of stainless steel on top.