The influence of the percent weight local material bentonite, quartz and magnetite of the capacity sorption Sr-90 in the radioactive waste

An experimental investigation on the influence of the percent weight local material bentonite, quartz and magnetite of the capacity sorption on the nuclide of Sr-90 used as a backfill material has been done. The nuclide of Sr-90 has high toxicity, so an experimental investigation on its absorbability is necessary since this nuclide can not be dispersed to the environment. This investigation was carried out by varying some parameters which influence the sorption ability or sorptive capacity of the local material used. The variables investigated were the backfill material composition of bentonite/quartz and bentonite/magnetite. They were varied from 100/0 to 0/100% by weight. The sorption capacity of the maximum results was also determined. It can be concluded that the DF obtained from the local material of bentonite was 86.40, the quartz was 14.19 and the magnetite was 18.83. Varied the composition of local materials can improve DF. At the composition of 30% bentonite/70% quartz, the DF obtained was 183.33, where as at the composition of 80% bentonite/20% magnetite, the DF obtained was 165.35. The sorption capacity of bentonite 100% was 8.62 x 10-3 μCi/g is the best sorption capacity. The initial activity of Sr-90 about 84.251 x 10-3 μCi/ml. The best result of activity of Sr-90 nuclide as the sorption residue was about 4.55 x 10-6 μCi/ml is still the range of safety limit if it dispersed to the environment, which is on in accordance with the maximum permissible concentration based on the safety limit of radiation work which is 2.7 x 10-6 μCi/ml. (The Director General's Decree No. PN 03/180/DJ/89). (author)