Constellation Energy Nuclear Group (CENG) has announced automatic shut down both units of the Calvert Cliffs nuclear power plant (CCNPP), located in Lusby, Maryland, US, due to an electric malfunction.

CCNPP spokesman Kory Raftery said in an e-mail to SoMdNews that a 4kV electrical bus connected to components on both units would have either tripped or went offline, leading to automatic shutdown.

The teams are currently investigating the causes of malfunction and will also make necessary repairs and test the systems before connecting the units to the grid, Raftery added.

US Nuclear Regulatory Commission spokesman Neil Sheehan wrote in an e-mail that the no immediate safety concerns were identified as a result of the malfunction.

”Our two Resident Inspectors for the plant will continue to monitor the company’s efforts to troubleshoot exactly what occurred, whether any repairs are needed and plans to restart the units,” Sheehan added.

The Calvert Cliffs nuclear plant has two 2700MW thermal (MWth) Combustion Engineering Generation II two-loop pressurized water reactors (PWR), and produce over 1,700MW of electricity, which power more than one million homes.