The temporary storage sites, located in Kawamata, Naraha and other municipalities near the crippled Fukushima No. 1 nuclear power plant, store soil, grass and other radiation-tainted waste generated by decontamination work due to the 2011 triple meltdown.
In Iitate, Fukushima Prefecture, where all residents remain evacuated, at least 82 black polyethylene bags containing tainted grass and other waste were swept from a site of decontamination work into a river.
Each bag can hold 1 cubic meter of waste.
An Iitate town official alerted the Environment Ministry’s Fukushima Office for Environmental Restoration around 6 a.m. on Sept. 11 that bags of waste were being swept away.
By 6 p.m., officials had retrieved 37 of the 82 bags. The remaining 45 bags got stuck under bridges and other obstacles along the river.
Ministry officials said none of the bags located thus far had spilled their contents and the impact on the environment was minimal.
At the Fukushima No. 1 nuclear plant, heavy rain caused radiation-tainted rainwater to spill into the ocean outside the plant’s harbor from the drainage system that encircles the reactor buildings on Sept. 9 and Sept. 11, Tokyo Electric Power Co. said.
Floodgates normally block tainted water from reaching the ocean from drainage ditches, but the torrential rains overwhelmed the gates twice in the pre-dawn hours of Sept. 9 and Sept. 11, the plant operator said.
Utility officials said rainfall increases the radioactive level of the water in the drainage system as rainwater accumulates radioactive materials in surrounding soil when it flows in the ditches.
While the drainage water usually contains less than 100 becquerels of beta-ray-emitting radioactive substances per liter, the water measured 750 becquerels per liter on Sept. 11, TEPCO officials said.
Source: Asahi Shimbun