Calvert Cliffs Shut Down Again

Unit 2, one of the 2 reactors at the Calvert Cliffs nuclear power plant in Southern Maryland, was unexpectedly shut down again on Tuesday May 21 around 5:30 am. Neil Sheehan, a spokesperson for the Nuclear Regulatory Commission (NRC), said that the reactor was manually taken off line because of high vibrations in the steam line. A failed coupling between the pump and the pump motor was the leading cause of these vibrations.

This same reactor was taken off line on Wednesday, May 8th, just two weeks prior to the latest shutdown. The first incident was blamed on an electrical malfunction that caused the valves to close, resulting in pressure buildup.

The reactor went back online at 8:50 am on Thursday after a 2 day shutdown. The NRC said that it is standard operating procedure to increase it's oversight at a facility that experiences 3 unplanned shutdowns within in a 10 month period.

The NRC Event Text Can be found here:
Event Number: 49054