Study on decontamination for cesium polluted soils by a chlorination-volatilization method

对核事故污染土壤进行了氯化挥发法去除铯的实验研究。在氯化实验之前，我们试图研究福岛县样品土壤中铯的分布特征对粒径分类的影响。将土壤颗粒高度精确地划分为纳米级，并利用高纯锗探测器对铯137和铯134的放射性进行了评价。在此基础上，以粒径小于5 μ m的膨润土样品为研究对象，对氯化挥发法的适用性进行了评价。结果发现，900℃以上的高温是有效的，可以使铯的挥发量比不加氯时增加100倍以上。

The experimental studies on removal of cesium by a chlorination-volatilization method were carried out for the decontamination of the polluted soils generated in the nuclear accident. Before the chlorination experiments, we tried to investigate the properties of cesium distribution towards particle sizes classifications of the sample soils collected in Fukushima prefecture. The soil particles were highly precisely classified into nano-meter sizes, and evaluated the radioactivies of cesium 137 and 134 using high purity germanium detector. On the base of the results, the applicability of the chlorination-volatilization method was evaluated employing bentonite sample composed of particles smaller than 5 um which was contribute most to cesium adsorption onto soils. As the result, it was found that the higher temperature over 900 C was effective that it may enhance the volatilization amount of cesium larger than 100 times larger than without its chlorination.