Prefectural Govt. finds radioactive sediment in rivers

April 1, 2016

Radioactive sediment found in Fukushima rivers

http://www3.nhk.or.jp/nhkworld/en/news/20160401_01/

Researchers in Japan have detected relatively high levels of radioactive substances in sediment in multiple rivers running through Fukushima Prefecture.

The prefectural government in January surveyed the density of radioactive materials in soil and other sediment that has accumulated on the bottoms and banks of 72 rivers in the prefecture. The study came in response to the 2011 nuclear accident at the Fukushima Daiichi power plant.

The researchers found up to 54,500 becquerels per kilogram of radioactive substances in the Maeda River in Futaba Town, where the plant is situated, and 39,600 becquerels in the Hiru River in Fukushima City. They also detected more than 10,000 becquerels at 5 other locations in 4 municipalities.

The prefectural government plans to study restricting access to rivers with high concentrations of radioactive materials. It also plans to ask the central government to remove contaminated soil and other sediment.

Officials of the Environment Ministry say the guidelines do not require decontamination outside living areas. But they add they will consider what to do with highly radioactive sediment after assessing the situation.