NIKKO, Tochigi Prefecture--At least 334 bags containing radioactive grass and soil from the Fukushima nuclear disaster cleanup have apparently been swept into a tributary of the Kinugawa river during recent torrential rains, according to Nikko city.
NIKKO, Tochigi Prefecture--At least 334 bags containing radioactive grass and soil from the Fukushima nuclear disaster cleanup have apparently been swept into a tributary of the Kinugawa river during recent torrential rains, according to Nikko city.
The city reported on Sept. 17 that 20 of the bags were recovered downstream but found to be empty, apparently having spilled their contents. The other 314 bags remain unaccounted for.
The sacks, each with a capacity of 1 cubic meter of waste, are filled with radioactive waste collected from the cleanup work following the accident at the Fukushima No. 1 nuclear power plant in March 2011.
Nikko Mayor Fumio Saito, however, said that the radiation level around the site where the bags are stored is still below the level at which decontamination work is required.
“The radiation level is so low that I believe there will not be a huge impact (on the surrounding environment),” he said.
A similar incident was reported earlier in Iitate, Fukushima Prefecture, where an estimated 395 black polyethylene bags containing tainted grass and other waste were confirmed Sept. 15 to have been swept from a decontamination work site into a river in torrential rain. At least 153 of the bags were found to be empty.
By 7 p.m. the same day, 393 bags were discovered and 202 of the 393 bags were retrieved. However, of 191 bags that have yet to be collected, the condition of 168 of the sacks remains unknown.
According to Nikko city, 558 bags holding radiation-tainted waste were stored at Kobyakugawa Sakura Koen park, which is situated alongside a tributary of the Kinugawa river.
The bags are protected by special sheets and mounds. However, at least 334 bags were apparently swept into the tributary after part of the embankment collapsed during the torrential rain. Some of the 132 bags of radioactive waste kept near the 558 bags also rolled down slopes in landslides that were triggered by the storms, the city said.
The radiation level around the storage site currently reads 0.14 microsieverts per hour at 1 meter above ground, below the threshold set by the central government of 0.23 microsieverts per hour that requires decontamination work.