Radioactive leak

about 20 tonnes of radioactive coolant water leaked from an eight-cm-long crack in a pipe at a nuclear power plant in Tsuruga, Fukui Prefecture, Japan, on July 12, officials of the Japan Atomic Power Co said. No radiation leaked outside the No 2 reactor building where the accident occurred, they said. It was the largest leak of coolant at a Japanese nuclear facility since 1979, when 95 tonnes spilled out at the No 2 reactor of the Takahama nuclear power plant, also in Fukui Prefecture. A similar accident hit the Tsuruga plant in December 1996, when a small amount of coolant leaked in the same reactor. The severity of the accident was assessed Level 1 by the Agency of Natural Resources and Energy, an affiliate of the Ministry of International Trade and Industry, which monitors accidents at nuclear power plants.

Level 1 is considered a "deviation" from normal operations on the international scale of 8 that begins at zero. A Level 2 event is regarded as an "abnormal" situation.