Tokyo Electric Power Co.'s stricken Fukushima No. 1 power plant has released rainwater tainted with radioactive substances into the Pacific Ocean at least seven times since April.
The Fukushima Prefectural Government, pressured by worried residents and fishermen, has pressed the Nuclear Regulation Authority to set maximum radiation limits for rainwater releases, but the regulator hasn't acted yet, citing the lack of specific laws on radioactive rainwater.
The plant's K channel, a gutter that was built to drain rainwater accumulated around the six reactors, leads directly to the sea. After rainwater was found tainted with radiation in April, Tepco, as a temporary fix, installed eight pumps and a special underwater curtain in its artificial bay to segregate the water from the open ocean.