Whether it was a blown fuse or a build up of snow and ice, two nuclear plants either shut down or ended up forced to reduce power this week.
Calvert Cliffs nuclear power plant in Lusby, MD, ended up shut down Tuesday night following an electric malfunction as a result of a build up of snow and ice.
The outage, which occurred at 9:25 p.m., resulted from a breakdown on the non-nuclear side of the Calvert County facility, officials said. Electric service to regional homes and businesses did not suffer as backup power systems jumped into action.
Calvert Cliffs spokesman Kory Raftery said the plant is in stable condition and there is no threat to public health and safety due to the shutdown.
Operators said the incident came about because of snow and ice having an impact on a ventilation louver filter on the facility housing the electrical supply, which resulted in a tripped breaker.
Meanwhile, the Vermont Yankee nuclear power plant in Vernon, VT, had to reduce power Wednesday when it blew a fuse.
The Nuclear Regulatory Commission (NRC) said the fuse, located in an electrical control circuit for the plant’s condenser steam jet air ejectors, caused a lowering of the condenser vacuum.
NRC spokesman Neil Sheehan said the incident, which occurred at 12:30 a.m. Wednesday, forced plant operators to reduce power in order to maintain vacuum conditions in the condenser. He said the air ejectors remove water vapor and other non-condensable gases from the condenser. The condenser cools the steam after it leaves the turbine. Sheehan said workers replaced the fuse, but the reason behind the blown fuse was still under investigation.
Entergy Nuclear spokesman Robert Williams said the plant was back at full power by 6 a.m., after repairs.