Original paper(Vol.52 No.5 pp.458)

Micro/Macro Treatment in Diffusion Problem-Clay and a Possibility for Mudstone-

Kazumi KITAYAMA, Naoki FUJII, Satoru SUZUKI, Masahiro SIBATA, Katsuyuki KAWAMURA and Yasuaki ICHIKAWA

Abstract:Diffusion in clay and mudstone is a peculiar phenomenon because of involved clay minerals. Clay and mudstone are a microinhomogeneous material. In order to understand the true behavior, first we specify the microstructure by a conforcal laser scanning microscope (CLSM) together with SEM, second the material properties of each constituent component are identified by a molecular dynamics simulation (MD), and third the microscale characteristics are related to the macroscale behavior by a multiscale homogenization analysis method (HA). Note that the bentonite generally consists of montmorillonite with the size of about 100nm and chalcedony with the size of about 10-50ƒÊm, so we introduce the multiscale HA with mesoscale and microscale systems. We show diffusion characteristics of tritium water (HTO) in bentonite. The numerical results of this MD/HA procedure are consistent experimental ones.

Key Words:Diffusion, Microscale characterization, Conforcal laser scanning microscope (CLSM), Molecular dynamics (MD), Multiscale homogenization analysis (HA), HTO, Clay, Mudstone