Evaluation of the performance of bentonite and hematite mixture as ashield in radioactive waste landfills

Nuclear technology has basic applications in various industries, but one of the main concerns about this technology is radioactive waste management. Low level radioactive wastes are usually disposed of in the landfills that have been isolated using natural and impermeable clay soil. This waste material is the source of gamma-ray that can make radiation pollution. Therefore, the performance of clay liner as a radiation shielding material on top and around these disposals is important. In this research, the effect of adding hematite powder to clay soil as a gamma-ray shielding is evaluated. The reason for using hematite powder is its high specific gravity. The linear attenuation coefficient (μ) has been measured experimentally using the Nal (Tl) detector. The samples were made in pure form with three different percentages of ۱۵%, ۳۰%, and ۴۵% were exposed to ۱۱۷۳ and ۱۳۳۲ keV energy with cobalt ۶۰ radioactive source. The results show the linear attenuation coefficient (μ) for the mixture including ۴۵% hematite powder is ۳۰ and ۵۰ percent more than pure bentonite clay soil for ۱۱۷۳ and ۱۳۳۲ keV, respectively.