The U.S. Nuclear Regulatory Commission (NRC) started special inspections at Constellation Nuclear Energy Group’s Calvert Cliffs nuclear power plant in Maryland following an unplanned shutdown of both units.
The team will begin work on Jan. 27 to review what happened during the event, including the response by plant operators and safety systems; the cause of the event and any related issues.
During a Jan. 21 winter storm, an electrical supply system that distributes some of the off-site power to the plant was temporarily interrupted. Initial reports say snow and ice affected a ventilation louver filter, causing a short-circuit that tripped Unit 2. The power loss also caused a malfunction in the Unit 1 main turbine control circuit, causing it to automatically shut down. Unit 2 returned to service on Jan. 25 and Unit 1 was back online on Jan. 26.
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