One of the two units at the Calvert Cliffs Nuclear Power Plant, located near Lusby, Md., was shut down after a malfunction.
Authorities are looking into an incident at the Calvert Cliffs nuclear plant, located 70 miles south of Baltimore in Maryland. The malfunction poses no risk to the public, but it did cause a major drop in power generation.
A spokesman said Monday that a control rod unexpectedly dropped into the reactor core. Control rods are used to regulate the pace of the nuclear reaction.
Dr. David Lochbaum is a nuclear expert with the Union of Concerned Scientists, a watchdog group. He says these types of events happen about once every two years at most U.S. nuclear plants.
"The event involved a malfunction that caused one of the control rods to drop into the reactor core as its designed to do — it's a failsafe mode," says Lochbaum.
The plant says it's inspecting Unit 1 and it will remain closed for maintenance. Most industry and outside experts including Lochbaum say the event does not pose a safety risk.
"The owner could have chosen to continue to operate the plant, but the owner also chose a prudent measure," says Lochbaum.
A plant spokesman says he can't predict when Unit 1 will return to operation. He says Unit 2 is running at full power.