Microbial influence on the sorption of137Cs onto materials relevant to the geological disposal of radioactive waste

A major concern in the geological containment of radioactive wastes is the speed of movement of radionuclides from the repository, after their eventual leaching and release, into the geosphere and finally into the biosphere. Radionuclide sorption onto the host rock is an important retarding mechanism. Experimental evidence shows that the presence of microbes in this environment influences the sorption capabilities of the host rock. Their presence can decrease the amount of retardation of137Cs, a common radionuclide in radioactive waste, by the solid phase. Sorption methods and data analysis procedures are presented and the implications for radioactive waste disposal assessments are discussed.