While Limerick Unit 2 continues to operate at full power, Unit 1 will remain offline until repairs, inspections and testing are completed, the plant operator Exelon said in a statement.

An Unusual Event was declared at 8:39 a.m. and terminated at 9:46 a.m. on Wednesday in keeping with NRC procedures, due to the electrical disturbance.

The Nuclear Regulatory Commission classifies an Unusual Event as the lowest of the four of its emergency classifications.

Exelon Generation has notified the event to the concerned government bodies, and said that the event is no threat to the health and safety of the public.

Located approximately 21 miles northwest of Philadelphia, the Limerick Generating Station with both units at full power can generate enough carbon-free electricity for 2 million homes.