The Unit 2 reactor at Diablo Canyon nuclear power plant shut down Sunday after an electrical disturbance occurred in equipment that moves power to the state’s electric grid.
Preliminary investigations indicate the disturbance was the result of a flashover event on a lightning arrester, which is located on the non-nuclear side of the plant, according to a PG&E news release. A flashover is an unintended arc between two pieces of electrical equipment.
The unit is designed to automatically go offline when disturbances occur to protect equipment, according to the news release.
Unit 2 will return to service after the equipment undergoes testing. PG&E has informed the U.S. Nuclear Regulatory Commission and local and state officials of the disturbance.
Unit 1 continues to generate power.