Operators of Limerick Generating Station shut down one of two electricity-generating reactors this morning following an electrical fault in non-safety equipment. Regional power supplies are not expected to be affected.
View full sizeBoth reactors at Exelon Corp.'s Limerick Generating Station in Montgomery County, Pa., are seen operating March 16, 2011. One was shut down this morning.The Limerick Generating Station entered into what the commission terms an unusual event, commission spokeswoman Diane Screnci said.
"It is stable and there was no impact on public health and safety," Screnci said, referring to the Unit 1 reactor.
There are about a dozen unusual events declared annually at the nation's 104 operating nuclear plants, Screnci said.
The Nuclear Regulatory Commission says it has resident inspectors at each plant, and those stationed at Limerick in Limerick Township, Pa., outside Pottstown, responded immediately.
The electrical fault occurred about 8:15 a.m. in a transformer that provides electricity to pumps that are part of electricity generation, not reactor cooling, the federal agency spokeswoman said. The plant operator, Chicago-based Exelon Corp., terminated the unusual event at 9:46 a.m.
"When the generation-cooling equipment is unavailable then our operators by procedure then begin to shut the plant down manually, and we were able to do that," Exelon spokesman David Tillman said. "That unit is offline this morning and it will remain offline until we can get in there, schedule the repairs, do the work, do the inspections" and complete testing to ensure safe operation.
Tillman said he could not estimate when the reactor would be restarted. He said the 1,200-megawatt reactor taken offline generates enough electricity for about 1 million homes. The plant's other 1,200-megawatt reactor was unaffected by the incident.
The shutdown comes amid high demand in soaring summer heat this week. It is not expected to affect the Mid-Atlantic power grid operated by PJM, also based in Montgomery County, in Lower Providence Township, Pa., a PJM spokesman said.
Allentown-based PPL Electric Utilities on Tuesday saw its highest power consumption of 2012 at just more than 7,000 megawatts between 5 and 6 p.m., spokesman Michael Wood said. The utility's usage record was more than 7,550 megawatts.
Due to high energy demand today, PPL is activating its load-control equipment for Peak Saver participants from noon to 6 o'clock, for a second straight day.
"With new curtailment programs, it is doubtful we will knock off any records this summer," Wood said in an email.
PJM said in May there is 185,180 megawatts worth of power-generation capacity for its 13-state region that includes Pennsylvania and New Jersey, plus the District of Columbia, and that peak demand this summer is forecast at 153,780 megawatts.
PJM spokesman Ray Dotter said the usage forecast for the grid includes a cushion to account for problems such as a reactor shutdown.
"We have not taken any steps that affect consumers and we don't expect to this afternoon," Dotter said, adding that the forecast for cooler weather heading into the weekend should reduce power consumption.
"In a nutshell, we expect that we have sufficient power supplies over the summer," Dotter said.
Of the unusual event, Screnci said: "It caused them to staff certain positions and make some communications, like they notified the state and NRC of such an event, but the plant responded as it is designed."
Public notification of such an incident is the responsibility of the governor's office and Pennsylvania Emergency Management Agency, Screnci said. PEMA spokeswoman Ruth Miller said the agency was in touch with both Exelon and the Pennsylvania Department of Environmental Protection Bureau of Radiation Protection.
"It wasn't at that point, the status of the incident did not require public notification," Miller said.