Skip to main content

Pump triggers Three Mile Island reactor shutdown, NRC says

By the CNN Wire Staff
September 20, 2012 -- Updated 2136 GMT (0536 HKT)
The Three Mile Island Nuclear Plant was shutdown Thursday.
The Three Mile Island Nuclear Plant was shutdown Thursday.
STORY HIGHLIGHTS
  • Three Mile Island plant shuts down for the second time in a month
  • Operators are trying to determine the cause of Thursday's shutdown
  • There was no danger to the public, the NRC and plant owner Exelon say
  • Three Mile Island's other reactor has been shut down since a partial meltdown in 1979

(CNN) -- The Three Mile Island nuclear power plant shut down unexpectedly Thursday when a reactor coolant pump failed, federal regulators said.

"This appears to be a fairly straightforward shutdown," said Neil Sheehan, a spokesman for the Nuclear Regulatory Commission. "Every indication we're getting is the reactor safety systems are performing the way they are designed."

The Unit 1 reactor shut off automatically about 2:20 p.m., the plant's owner, Exelon Corporation, reported. There is no danger to the public, but the release of steam in the process created "a loud noise heard by nearby residents," the company said.

Sheehan said one of the four reactor coolant pumps appears to have stopped working. Though three others remain, the system shuts down when an anomaly is detected, he said.

Thursday marked the second time in a month that the reactor has been shut down, following an August 22 leak in a heating system used to pressurize water. The unit was replaced, inspectors found no signs of a problem in two other units and the reactor returned to service on September 5, according NRC records.

The 825-megawatt pressurized water reactor at Three Mile Island, about 10 miles outside Harrisburg, Pennsylvania, has been in service since 1974 and can power about 800,000 homes. There was no loss of electrical service after Thursday's shutdown, Exelon said.

The Unit 2 reactor has been shut down since a partial meltdown in 1979. There were no injuries and little release of radiation from that incident, which remains the worst commercial nuclear accident in U.S. history.

2011: U.S. agencies provide insight into how to prepare for, respond to nuclear disaster

CNN's Mike M. Ahlers and Sonia Kennebeck contributed to this report.

ADVERTISEMENT
Part of complete coverage on
February 6, 2013 -- Updated 1526 GMT (2326 HKT)
Advocates say the exam includes unnecessarily invasive and irrelevant procedures -- like a so-called "two finger" test.
February 6, 2013 -- Updated 0009 GMT (0809 HKT)
Supplies of food, clothing and fuel are running short in Damascus and people are going hungry as the civil war drags on.
February 6, 2013 -- Updated 1801 GMT (0201 HKT)
Supporters of Richard III want a reconstruction of his head to bring a human aspect to a leader portrayed as a murderous villain.
February 5, 2013 -- Updated 1548 GMT (2348 HKT)
Robert Fowler spent 130 days held hostage by the same al Qaeda group that was behind the Algeria massacre. He shares his experience.
February 6, 2013 -- Updated 0507 GMT (1307 HKT)
As "We are the World" plays, a video shows what looks like a nuclear attack on the U.S. Jim Clancy reports on a bizarre video from North Korea.
The relationship is, once again, cold enough to make Obama's much-trumpeted "reset" in Russian-U.S. relations seem thoroughly off the rails.
Ten years on, what do you think the Iraq war has changed in you, and in your country? Send us your thoughts and experiences.
February 5, 2013 -- Updated 1215 GMT (2015 HKT)
Musician Daniela Mercury has sold more than 12 million albums worldwide over a career span of nearly 30 years.
Photojournalist Alison Wright travelled the world to capture its many faces in her latest book, "Face to Face: Portraits of the Human Spirit."
February 6, 2013 -- Updated 0006 GMT (0806 HKT)
Europol claims 380 soccer matches, including top level ones, were fixed - as the scandal widens, CNN's Dan Rivers looks at how it's done.
February 6, 2013 -- Updated 1237 GMT (2037 HKT)
That galaxy far, far away is apparently bigger than first thought. The "Star Wars" franchise will get two spinoff movies, Disney announced.
July 25, 2014 -- Updated 2327 GMT (0727 HKT)
It's an essential part of any trip, an activity we all take part in. Yet almost none of us are any good at it. Souvenir buying is too often an obligatory slog.
ADVERTISEMENT