One of two reactors at the Calvert Cliffs nuclear power plant in southern Maryland was shut down again Tuesday, the second unplanned outage in the past two weeks.
Plant operators powered down Unit 2 manually around 5:30 a.m. after a pump that feeds water to a steam generator shut down because of high vibrations, according to Neil Sheehan, spokesman for the Nuclear Regulatory Commission. The cause of the pump's vibrations appears to be a failed mechanical coupling between the pump's motor and the pump, he said.
Sheehan and Kory Raftery, spokesman for Constellation Energy Nuclear Group, said the manual shutdown went smoothly and posed no safety risks for plant workers or the public. Raftery said the reactor was in "stable condition."