Activation energy for diffusion of helium in water-saturated, compacted Na-montmorillonite |
| |
Authors: | Tomohiro Higashihara Tamotsu Kozaki |
| |
Affiliation: | Division of Quantum Energy Engineering, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan |
| |
Abstract: | It is important to clarify the migration behavior of hydrogen gas dissolved in water-saturated, compacted bentonite, which is a promising material for geologic disposal of high-level waste and TRU waste disposal. The diffusion coefficients of helium, which can be detected under extremely low background conditions, in water-saturated, compacted Na-montmorillonite were determined as a function of temperature by a transient diffusion method. The activation energies for diffusion of helium were then obtained. The activation energies were from 6.9 ± 4.8 to 19 ± 2.8 kJ mol− 1 and were regarded to be independent of dry density. The activation energies of helium in water-saturated Na-montmorillonite were roughly equal to those in bulk water, 14.9 kJ mol− 1, and in ice, from 11 to 13 kJ mol− 1. It is possible that helium diffuses not only in pore water but also in interlayer water. |
| |
Keywords: | Helium Diffusion coefficient Activation energy Na-montmorillonite Transient diffusion method Compacted bentonite Water saturation Mass spectrometry |
本文献已被 ScienceDirect 等数据库收录! |
|