By: Charles Slat Monroe News, Michigan story updated October 11. 2007 8:32PM
DTE finds holes drilled in Fermi safety system line.
DTE Energy declared a low-level emergency at its idled Fermi 2 nuclear plant Thursday after finding small holes that apparently were drilled into a steam line associated with a safety relief valve at the base of the reactor.
Plant officials said they don’t know how many holes exist, how they got there or whether they existed while the plant was operating.
The plant has been shut down for maintenance and refueling and the damage was discovered during routine inspections of the plant’s drywell, part of the system designed to contain radioactive steam and pressure during a rapid shutdown or accident at the plant.
After discovering the series of quarter-inch holes, the utility halted work in that area of the reactor and evacuated personnel so it could investigate the find.
"We don’t know why the holes were drilled in that location," said John J. Austerberry, a DTE spokesman.
"To facilitate a thorough inspection, we cleared all non-essential personnel from the drywell," he said.
He said it wasn’t clear whether the holes resulted from an error or might have been deliberate.
"We are conducting a vigorous and thorough investigation," he said. He said the holes were discovered during an equipment inspection designed to detect any abnormalities.
The utility declared an "unusual event," the lowest of four federal emergency classifications at nuclear plants, and notified federal, state and local officials of the discovery.
Mr. Austerberry said it was uncertain when the investigation would be completed.
He did not know if the discovery might somehow be related to a leaking valve that was discovered on a feedwater check line in the plant on Sunday. That also was reported to the federal Nuclear Regulatory Commission because it could have affected safety systems if the plant was operating.
Fermi 2, an 1,100-megwatt boiling water reactor that began operating in 1988, was shut down about two weeks ago for a refueling and maintenance outage that is expected to take little more than a month.