ADVERTISEMENT

BEIJING – The operator of the tsunami-damaged nuclear plant at Fukushima, Japan, said Tuesday that 300 tons of highly radioactive water has leaked from one of its storage tanks, the worst of a number of similar leaks since the catastrophic 2011 earthquake and tsunami.

Tokyo Electric Power Co. said that the leak, discovered Monday morning at the Fukushima Daichi nuclear power plant, posed no immediate threat to Pacific Ocean waters. The accident was classified by Japan’s nuclear regulator as a Level 1 incident, the second-lowest on the scale of nuclear accidents, as classified by the International Atomic Energy Authority.

Still, it was a serious setback in the efforts to contain and clean up the damage that crippled the plant in March 2011, the world’s worst nuclear disaster since Chernobyl in 1986.