OAK HARBOR, Ohio - Davis-Besse's attempted restart is on hold because its turbine generator was recoiled with aluminum instead of copper, throwing it out of balance.
Todd Schneider, a FirstEnergy Corp. spokesman, last night declined to say whether that was a mistake on the part of the utility or an unnamed contractor that rebuilt the generator in the Chicago area.
The work was done while the Ottawa County nuclear plant was offline for its latest refueling outage starting Dec. 30.
"I'm not going to get into the blame game," Mr. Schneider said.
While refusing to discuss what went wrong with the generator, he confirmed the part is being fixed.
The problem has been another costly one for FirstEnergy: Nuclear plants can generate upward of $1 million a day in power. The utility has been trying to get the plant back online since Friday.
With Davis-Besse's reactor at 19 percent power, just shy of what is needed for the plant to start producing electricity again, FirstEnergy paused the restart because of excessive vibrations.
The Nuclear Regulatory Commission learned the weight difference between the aluminum and the copper apparently was enough to throw the rebuilt generator out of balance, causing the vibrations.
The utility kept trying to fix the problem with the reactor at 19 percent power until yesterday, when it decided it was time to shut it down and try again.
"Now we are removing the generator and replacing a component. Hopefully, that will eliminate the vibration problem," Mr. Schneider said.
He described the work as a "relatively short" procedure, but would not say when he expected the plant's restart effort to resume.
The latest work to the generator is being done on site, he said.
"We tried several ways to remedy the problem, but that didn't work," Mr. Schneider said.
Viktoria Mitlyng, an NRC spokesman, said the agency's reactor branch chief and its resident inspectors are being kept abreast of the situation.
The turbine and the generator associated with it are electrical components in a nonnuclear part of the plant.
The Toledo area's other nuclear plant, DTE's Fermi 2 in northern Monroe County, was back at full power yesterday, according to NRC records.
Fermi 2's reactor was shut down last Thursday because its recirculation pumps malfunctioned. DTE traced the problem to one of four switches associated with the plant's under-voltage relay system, which protects pumps from low voltage.
Ms. Mitlyng said there were no problems with Fermi 2's restart, which began Sunday.
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