1. Geological Survey of Japan; Institute of Geology and Geoinformation; AIST, Higashi 1-1-1, Central 7 Tsukuba Ibaraki 305-8567 Japan
2. Faculty of Science; Ibaraki University; Bunkyo 2-1-1 Mito Ibaraki 310-8512 Japan
3. Moriya City Office; Ogashiwa 950-1 Moriya 302-0198 Japan
4. National Cooperative for the Disposal of Radioactive Waste (NAGRA); Hardstrasse 73 5430 Wettingen Switzerland