UPDATE 2-Exelon shuts Pa. Limerick 1 nuclear power reactor

By Scott DiSavino
July 18 (Reuters) - Exelon Corp shut down the
1,130-megawatt (MW) Unit 1 at the Limerick nuclear power plant
in Pennsylvania early Wednesday following an electrical
disturbance on the non-nuclear side of the plant, the company
said in a release.
The outage came at a bad time for the power grid: Homes and
businesses in the U.S. Mid-Atlantic are cranking up their air
conditioners amid a brutal heat wave blanketing the region.
The electrical disturbance caused a loss of power to
generator cooling equipment, the company said. The unit will
remain offline until repairs, inspections and testing are
completed, it said.
The company said the unit shutdown did not pose any threat
to the public.
The U.S. Nuclear Regulatory Commission (NRC) said the plant
experienced an electrical fault in a transformer that led to a
manual shutdown.
The failed 13-kilovolt (kv) transformer was located in the
plant's control structure, which houses the control room and is
also usually the location of electrical switchgear rooms,
battery rooms and other equipment rooms, the NRC said.
The NRC said there was no impact on the control room from
this event.
The 1,134-MW Limerick Unit 2 continued to operate at full
power, the company said.
The company also said it declared an "unusual event" as a
result of the electrical disturbance. An unusual event is the
lowest of four NRC emergency classifications.

----------------------------------------

PLANT BACKGROUND/TIMELINE
STATE: Pennsylvania
COUNTY: Montgomery
TOWN: Pottstown about 40 miles (64 km) northwest of
Philadelphia
OPERATOR: Exelon Nuclear
OWNER(S): Exelon Corp
CAPACITY: 2,264 MW
UNIT(S): 1 - 1,130-MW General Electric boiling water
reactor
2 - 1,134-MW General Electric boiling water
reactor
FUEL: Nuclear
DISPATCH: Baseload
TIMELINE:
1969 - Philadelphia Electric Co (PECO - now a part of
Exelon) selects the site
1974 - Construction starts following community protests
and other delays
1984 - Unit 1 starts producing power
1986 - Unit 1 enters commercial service
1989 - Unit 2 starts producing power
1990 - Unit 2 enters service
2011 - Exelon files with the NRC for 20-year extensions of
the original 40-year operating licenses
2013 - NRC likely to decide on license renewals
2024 - Unit 1 license expires
2029 - Unit 2 license expires