Apparent diffusion coefficients of uranium, neptunium and technetium in compacted bentonite under reducing conditions

*; Nakazawa, Toshiyuki*; Ueta, Shinzo*; Shibata, Masahiro

JNC TN8400 99-069, 41 Pages, 1999/11

JNC-TN8400-99-069.pdf:1.62MB

As a part of the evaluation for the sorption phenomena of nuclides in compacted bentonite, apparent diffusivities for uranium, neptunium and technetium that are redox-sensitive elements, were measured under reducing conditions. Bentonite used was a sodium bentonite, Kunigel V1. Apparent diffusivities were measured by using in-diffusion method (concentration profile method), under the conditions with varying dry densities of compacted bentonite and sorts of the solution used for water saturation of bentonite in diffusion experiments. As a result of the measurements, following ranges of values for apparent diffusivities were acquired. ...