TOKYO - Water containing radioactive substances leaked at the decommissioning site of the nuclear reactor Fugen in Fukui Prefecture in central Japan on Tuesday, raising the possibility that several workers may have been exposed to radiation, local media reported.

According to Hokuriku Broadcasting, tritium levels increased during dismantling work at an auxiliary building at the prototype advanced thermal Fugen in Tsuruga City, Fukui Prefecture, which has been undergoing decommissioning.

No impact on the external environment has been confirmed, the report said.