NEWPORT, Mich., Oct. 12 /PRNewswire/

The investigation into Thursday's discovery of one small hole and five small indentations in piping at the Fermi 2 Power Plant has determined that the damage was unintentional. The damage to the pipes does not cause a safety concern because the plant has been shut down for almost two weeks for a planned outage.

Fermi 2 site vice president Joseph Plona said the hole and indentations appear to be related to drilling done during the removal of insulating material from the pipes, which are located in an area of the plant referred to as the drywell. The insulation removal was performed earlier this week as part of the scheduled outage maintenance work.

The plant's planned refueling and maintenance outage, which typically occurs every 18 months at Fermi 2, began Sept. 29. Approximately 2,700 individual tests, inspections and maintenance activities are conducted, in addition to replacing about one fourth of the plant's fuel assemblies. The damaged steam lines all are associated with the plant's safety relief valves. These valves are designed to relieve pressure in the plant reactor under certain conditions. The safety relief valves do not serve a safety function when the plant is not operating.

Plona noted that the damage was discovered by plant personnel during a routine inspection of plant systems. Based on the site emergency plan, the company subsequently declared an Unusual Event, the lowest of the NRC's four emergency classifications. The classification is required when there is potential degradation of the safety in the plant. The Unusual Event was canceled late this afternoon.

"While we can confirm that the holes were not made deliberately, we will continue to look into the circumstances and adherence to procedures surrounding this incident, " Plona said. "Our inspections of plant systems are intended to ensure the integrity of plant equipment prior to startup following our refueling and maintenance outage."

The refueling and maintenance outage is scheduled to conclude in November. An assessment of the overall refueling outage schedule and associated impact from this incident is under review.

The Fermi 2 Nuclear Power Plant, which began commercial operation in 1988, is an 1,100-megawatt boiling water reactor owned and operated by Detroit Edison in Southeastern Michigan. The plant has produced more than 134 billion kilowatt hours of electricity for Detroit Edison customers.

Detroit Edison is an investor-owned electric utility serving 2.3 million customers in Southeastern Michigan and a subsidiary of DTE Energy (NYSE: DTE), a Detroit-based diversified energy company involved in the development and management of energy-related businesses and services nationwide. Information about DTE Energy is available at http://www.dteenergy.com.