3,000,000 Bq/m2 of cesium from the dam in Fukushima


Following up this article..Fukushima local gov is dumping radioactive mud from decontamination to Abukuma river

Ministry of Education, Culture, Sports, Science and Technology found out high level of cesium is concentrated in the bottom of the lake called Horai dam. This dam is to generate electricity, located in Nihonmatsu (60km North west to Fukushima plants), where is in Abukuma river.
Prof. Onda from Tsukuba university reported the mud sample taken in 20 cm deep underground of the bottom of the lake contained 3,000,000 Bq/m2 of cesium, where other samples taken in 4 other reservoirs around Horai lake showed 200,000~400,000 Bq/m2 of cesium.(July and August in 2011)  3,000,000 Bq/m2 is as contaminated as soil of 20km area.

Prof. Onda explains, cesium doesn’t melt into the water. Water of downstream is not harmful to drink.
However, they also found out that when the soil is highly contaminated, water of the downstream river is also highly contaminated, which proves Prof. Onda is wrong. Cesium was attached to the small swimming sand, which is smaller than 0.1mm diameter.
Ministry of Land, Infrastructure, Transport and Tourism states there is the risk of the contaminated mud to flow into the downstream in flood, but there is no plan of decontamination at the moment.

Other nuclides such as strontium or plutonium were not tested.

放射性物質:ダム底の泥に 雨で川へ流れ濃縮か 福島





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This website updates the latest news about the Fukushima nuclear plant and also archives the past news from 2011. Because it's always updated and added live, articles, categories and the tags are not necessarily fitted in the latest format.
I am the writer of this website. About page remains in 2014. This is because my memory about 311 was clearer than now, 2023, and I think it can have a historical value. Now I'm living in Romania with 3 cats as an independent data scientist.
Actually, nothing has progressed in the plant since 2011. We still don't even know what is going on inside. They must keep cooling the crippled reactors by water, but additionally groundwater keeps flowing into the reactor buildings from the broken parts. This is why highly contaminated water is always produced more than it can circulate. Tepco is planning to officially discharge this water to the Pacific but Tritium is still remaining in it. They dilute this with seawater so that it is legally safe, but scientifically the same amount of radioactive tritium is contained. They say it is safe to discharge, but none of them have drunk it.


March 2012