The Calvert Cliffs nuclear power plant restarted its reactor that automatically shut down last week after a malfunction at the Southern Maryland facility.
Operator Exelon Corp. said Monday that the Unit 1 reactor returned to full power at 9 a.m. Sunday. The facility's second reactor continued to run during the outage, one of three incidents in the last eight months in which one or both of the units had unplanned shutdowns.
The malfunction that caused Unit 1 to power down Thursday morning happened during electrical breaker testing, Exelon said. The U.S. Nuclear Regulatory Commission said that day that safety systems functioned as designed during the shutdown.