“…Previous studies have concentrated on pure bentonite (eg. Muurinen, 1990;Hsu et al, 1994;Jansson and Eriksen, 2001;Molera, 2002: Garcia-Gutierrez et al, 2006Suzuki et al, 2007) because of its proposed use in manmade barriers in radioactive waste disposal, and rocks from locations of prospective waste facilities (Sato et al, 1997;Lee et al, 2009;Wersin et al, 2008). Apparent diffusivities for various radionuclides are reported in many studies (Muurinen, 1990;Hsu et al, 1994;Sato et al, 1997) but, because the apparent diffusivity is affected by porosity and sorption, and the latter is sensitive to environmental conditions, these values are not readily applicable to other sites.…”