Tokyo Electric Power Co. (9501.TO) said Tuesday that the sound of an explosion was heard at the Fukushima Daiichi nuclear complex, but radiation levels haven't increased and no injuries were reported, Kyodo News reported. The explosion was heard around 0530 GMT as wreckage was being removed by remotely controlled heavy machinery on the southern side of the No. 4 reactor building.
Tepco said it was possible that a machine ruptured a buried gas tank, causing the explosion, the report said. Source
