OAK HARBOR, Ohio (AP) - Acid may have started leaking onto the steel cap of the Davis-Besse nuclear plant as long as eight years ago but the resulting decay was not noticed until recently, the plant's owner said in a preliminary report.
Earlier this month, plant workers discovered two holes in a steel cap that covers a reactor vessel of the nuclear power plant located about 25 miles east of Toledo. Federal inspectors said it was the most extensive corrosion ever found on top of a U.S. nuclear plant reactor.
Plant staff and management for years did not realize the significance of dry boric acid deposits on top of the vessel head, according to a five-page report by FirstEnergy Corp. provided to the Nuclear Regulatory Commission late Monday. Akron-based FirstEnergy operates the plant.
FirstEnergy spokesman Ralph DiNicola said Tuesday the report has no effect on plans to make repairs and expects to have the shutdown plant producing electricity again by late June.
At a recent planned maintenance shutdown, engineers found a 6-inch cavity of carbon steel that covers the radioactive fuel core. Later, they found a second cavity about 1 3/4 inch deep.
The discovery prompted the Nuclear Regulatory Commission to ask the nation's 68 other nuclear power plants of similar design to check for similar corrosion problems.