Reportedly, the Unit 1 reactor at Three Mile Island ceased operating at about 2:20 p.m. on Sept. 20, said Exelon Corporation, the owner of the nuclear facility. A loud noise could be heard by residents in the area as the reactor shut down and steam was released.
Three Mile Island is the nuclear facility where one of the reactors, Unit 2, experienced a partial meltdown in 1979 and was one of the worst nuclear accidents
in U.S. history.
In this case, officials are saying the mechanisms acted as designed. There are four reactor coolant pumps, but if one goes, the reactor's computer system is designed to shut down "when an anomaly is detected."
"This appears to be a fairly straightforward shutdown," said Neil Sheehan, a spokesman for the Nuclear Regulatory Commission (NRC). "Every indication we're getting is the reactor safety systems are performing the way they are designed."
Exelon and the NRC both say this incident did not pose any danger to the public and no "detectable levels" of radiation were released.
According to CBS News
, the TMI alert group, a watch group, is concerned about the aging of Three Mile Island, noting the facility was relicensed in 2009.
"Anytime a plant shuts down on short notice it normally releases radiation. This is not good radiation is cumulative in nature it's going to take some time to reconstruct the even and see how much was actually released. The way to prevent this from occurring again is to make sure all the parts in the plant are operating as they should." Says Eric Epstein, TMI Alert.
According to CNN
, this was the second time in the past month Three Mile Island has shut down. The last shutdown was on Aug. 22 when a heating system leak occurred. Service was returned on Sept. 5.
As of this morning, the Nuclear Regulatory Commission website
has Three Mile Island listed as operating at "zero" power. The facility has been operational since 1974 and powers approximately 800,000 homes, said the CNN report.
Sheehan told the Associated Press
yesterday that as soon as the reactor cools down enough, workers can access the problem and then make repairs.
At this time it is not known how long the facility will be shut down.