The heat induced moisture movement in buffer materials to be used for
the geologic disposal of high-level radioactive waste is investigated
by a series of experiments and numerical simulations. Highly compacted
blocks of Japanese Na bentonite are used in the experiments as the bu
ffer materials. Mechanistic models including those proposed by Philip
et al. and Ewen et al. are formulated to the finite-element program wh
ich are applied to interpret the experimental results. The applicabili
ty of the mechanistic models to the compacted bentonite is examined. T
he numerical results agree well with the experimental results qualitat
ively, though a few quantitative discrepancies are found. Those discre
pancies demand better descriptions for material properties on compacte
d bentonite and introducing an effect of volume change associated with
change in water content.