1. Hiroshima University, Civil and Environmental Engineering Program, 1-4-1 Kagamiyama, Higashi-Hiroshima-shi, Hiroshima 739-8527, Japan.
2. Taiheiyo Consultant Co. Ltd., Electric and Nuclear Power Technology Department, 2-4-2, Ohsaku, Sakura-shi 285-0802, Japan.
3. Radioactive Waste Management Funding and Research Center, Research and Development of Geological Disposal Barrier System, 6-4, Akashicho, Chuo-Ku, Tokyo 104-0044, Japan.
4. Paul Scherrer Institute, Laboratory for Waste Management, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland.