FirstEnergy moves up installation of reactor head at Davis-Besse after NRC discussions

6/21/2010

OAK HARBOR, Ohio — FirstEnergy Corp. announced Monday it will move up installation of its new Davis-Besse reactor head by three years.

The device will be installed in the fall of 2011 instead of 2014.

According to the Nuclear Regulatory Commission, FirstEnergy expedited the timetable after learning the regulatory agency was uncomfortable with the utility's plans to keep Davis-Besse operating until its next refueling outage 21 months from now. Nuclear plans typically go two years between refuelings. Davis-Besse has been offline since Feb. 28.

The NRC wants the existing head, put into service in 2004, inspected more frequently.

"Our calculations were much more conservative," Viktoria Mitlyng, NRC spokesman, said. "After the discussions, the utility just decided to replace the head."

She said the NRC's findings will likely be released Wednesday.

The existing head was installed following the plant's record two-year outage that occurred after the plant's old reactor head nearly burst. If it had, radioactive steam would have formed.

Both devices were made years ago of Alloy 600, a type of metal being phased out in the nuclear industry because of its propensity to crack under prolonged heat and stress. The new head will be made of Alloy 690, a more robust type of metal.

The existing head is a temporary replacement brought in from a mothballed plant in Midland, Mich., that Consumers Power, now Consumers Energy, never completed.

Both the NRC and the utility initially thought the replacement head would last 10 to 15 years before showing signs of aging. Heads at other nuclear plants have lasted more than 25 years without developing leaks — but Davis-Besse has long been the nation's hottest-operating nuclear plant.

The replacement head was found to be leaking in one of its 69 control-rod drive mechanism nozzles following Davis-Besse's Feb. 28 shutdown. Tests showed flaws developing in another 23 of the nozzles, which jut out of the top of the head and are used by operators to move control rods. That controls the plant's nuclear fission process.

Contact Tom Henry at:

thenry@theblade.com

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