Coupled thermo-hydro-mechanical modelling of bentonite buffer material

✍ Scribed by Kanno, T.; Fujita, T.; Takeuchi, S.; Ishikawa, H.; Hara, K.; Nakano, M.

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 807 KB
• Volume: 23
• Category: Article
• ISSN: 0363-9061
• DOI: 10.1002/(sici)1096-9853(199910)23:12<1281::aid-nag32>3.0.co;2-i

✦ Synopsis

Mechanistic model development and numerical analyses were carried out on coupled thermo-hydraulicmechanical processes in bentonite-based bu!er material for the geological disposal of high-level radioactive waste with small-scale laboratory experiments and a full-scale test. The mechanism of water movement in compacted bentonite was identi"ed by applying theoretical equations to the experimental results. The application clearly explained the observed results of the temperature dependence of the hydraulic conductivity in the saturated state and the water di!usivity in the unsaturated state for the compacted bentonite and the dry density dependence of the di!usivity. The full-scale coupled test, BIG-BEN, was conducted at PNC (Power Reactor and Nuclear Fuel Development Corporation) Tokai Works. The results of the numerical analyses for the full-scale test which are based on the present knowledge of coupled processes and our small-scale experiments were in good agreement with the measured results except for mechanical phenomena.