Effect of silver chloride deposition technique on modified bentonite operating properties for radioactive iodide-ions localization in geological disposal facility for radioactive waste

This work discusses the influence of the technique of silver chloride deposition (via one-stage or two-stage method) onto performance attributes of modified bentonite for iodine ions localization in radioactive waste repositories. It has been established that bentonite modified via both techniques in wide range of AgCl content has high sorption properties (more than 95%) towards iodide anions, the AgCl deposition method has little-to-no effect on sorption properties. Investigation by scanning electron microscopy and energy dispersive X-ray spectroscopy methods and studying of silver leaching in various media showed that two-stage technique yield more uniform AgCl distribution and significantly higher resistance of AgCl to leaching than one-stage technique. Therefore, as a component of bentonite engineered safety barrier in geological disposal facility for radioactive waste use of bentonite modified with two-stage technique is preferable.