A nuclear reactor in California was shut down last night after a leak was found in a steam generation tube. The reactor supplies 1.1GW of energy and is one of a pair that provides enough power for 1.4 million average households in southern California.

The plant’s operators were confident there was no threat caused by the leak. Southern California Edison said in a statement: “The potential leak poses no imminent danger to the public or plant workers. There has been no release to the atmosphere.”