A nuclear reactor in Alabama automatically shut down because of an electrical problem, but regulators say there is no threat to the public.

Officials report the Unit 1 reactor at Plant Farley south of Dothan automatically shut down around 9 p.m. on Tuesday. No radiation was released. Plant operators did not report any damage that could threaten the public.

An initial report filed with the U.S. Nuclear Regulatory Commission said the plant experienced a failure with an electrical transformer. As a result, the reactor automatically shut down and one of its emergency diesel generators started up.

Plant officials reported that the cause of the failure is under investigation. Atlanta-based Southern Co. could not immediately comment, but officials planned to release more details later Wednesday.

The plant’s second reactor was unaffected.