Nuclear Event - Maryland : Reactors at nuclear power plant in southern Maryland shut down last week after an electrical malfunction

Nuclear regulators send inspectors to Calvert Cliffs

Reactors at nuclear power plant in southern Maryland shut down last week after an electrical malfunction

• 

By Jamie Smith Hopkins, The Baltimore Sun

7:50 p.m. EST, January 27, 2014

The Nuclear Regulatory Commission announced Monday that it is conducting a special inspection at the Calvert Cliffs nuclear power plant in Southern Maryland after an electrical malfunction caused the two reactors there to shut down.
The plant, which restarted both reactors over the weekend, suffered the shutdown after snow and ice during a storm Jan. 21 apparently affected a ventilation louver filter and caused a short circuit. After the electrical supply system shut down, so did several plant systems and components that rely on electricity, the nuclear regulatory agency said Monday.
Those components included motors for moving control rods and water circulating pumps for the Unit 2 reactor, the agency said. The main turbine control circuit for the Unit 1 reactor also malfunctioned after the electricity loss.

Both units shut down as a result, with "no impacts on public health and safety," the agency said.
The three-person inspection team began working at the plant Monday, the commission said.
"We want to gain a better understanding of the chain of events that caused both of the reactors to simultaneously shut down and equipment anomalies subsequent to the plant trips," said Bill Dean, the commission's administrator for the region that includes Maryland, in a statement. "This inspection is designed to shed additional light on not only why the outages happened but how the plant operators handled them."
A Constellation Energy Nuclear Group spokesman said in an email that federal reviews after shutdowns are common, adding that the company welcomed the inspection at its plant.
"Operators followed their training and performed well during the shutdowns," said Kory Raftery, the spokesman. "The site's multiple safety systems responded as designed."
But Neil Sheehan, a Nuclear Regulatory Commission spokesman, said such inspections are not common.
Read More Here
Related

• Control rod problem shuts down Calvert Cliffs reactor

• Electric malfunction shuts down Calvert Co. power plant

.....

• Inspections find flaws in nuclear plant mechanism during scheduled outage

• “NRC inspectors have been reviewing the plant’s inspections and assessments and are reviewing the licensee’s replacement and repair plans, which will be completed prior to plant startup,” said Viktoria Mitlyng, senior public affairs officer for the NRC in this region. “The NRC will continue to evaluate and validate the licensee’s response to the issue to ensure plant safety.”

  The plant shut down Jan. 19 to replace 64 fuel assemblies and conduct maintenance, tests and inspections on equipment including the reactor vessel and its two low-pressure turbines.

  The facility remains offline.

  The control rod drive mechanism housings are part of the reactor coolant system boundary designed to prevent reactor coolant from leaking, Mitlyng said. There was no evidence of leakage.

  Read More Here

.....

Related articles

• Calvert Cliffs nuclear plant shuts down following electric malfunction
• Nuclear regulators send inspectors to Calvert Cliffs
• 2 Nuclear Reactors Shut Down at Md. Plant
• Inspections find flaws in nuclear plant mechanism during scheduled outage
• During Palisades refueling shutdown, flaws discovered in control rod drive housings
• Calvert Cliffs nuclear power plant shut down due to electric malfunction