Comparison of 0.1 M Stable CsCl and 1 M NH 4 NO 3 as an Extraction Reagent to Evaluate Cs-137 Mobility in Soils

To evaluate the mobility and bioavailability of Cs in soils, we compared the extraction of Cs with stable Cs and ammonium solutions from Cs-contaminated minerals and soils. The extraction yields of Cs with stable Cs were significantly lower than those with ammonium for minerals with frayed edge sites, but such differences were not observed for minerals without frayed edge sites. The amount of Cs extracted with stable Cs from soils was lower than, or equal to, that extracted with ammonium. The above results suggest that stable Cs extracted the Cs from easily accessible sites. Plant available Cs was assessed using Kochia (Bassia scoparia) cultivated in pots of contaminated soils, and compared with soil parameters including extractable Cs and K, and radiocesium intercept potential. The Cs/K ratio extracted with stable Cs solution was found to be a potential index for evaluation of the easily mobile and bioavailable fraction of Cs in soil.