Inhibition of 137CS contamination in cesium iodide

We have extensively studied the mechanism of the Cs-137 and (CS)-C-134 contamination in CsI compounds. The nuclei Cs-137 and (CS)-C-134 in various samples have been studied using a HPGe detector at deep underground. The main source of the (CS)-C-137 contamination in CsI powder was water dissolved (CS)-C-137 used in the chemical process of cesium extraction at company side. We also found that (CS)-C-134 was produced mainly from Cs-133 by neutron capture. We have successfully produced CsI powder containing no more than 2 mBq/kg of Cs-137 by using only ultra-pure water for whole extraction process from raw ore (pollucite). (c) 2005 Elsevier B.V. All rights reserved.