*Hiroki Nishimura1,2, Mariko Kouduka1, Akari Fukuda1, Toyoho Ishimura3, Yuki Amano5,4, Hikari Beppu5, Kazuya Miyakawa4, Yohey Suzuki1
(1.Graduate School of Science, Department of Earth and Planetary Science, The University of Tokyo, 2.Biogeochemistry Research Center (BGC), Research Institute for Marine Resources Utilization (MRU), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 3.Kyoto University, Graduate School of Human and Environmental Studies, 4.Horonobe Underground Research Center, Japan Atomic Energy Agency, 5.Nuclear Fuel Cycle Engineering Laboratories, Japan Atomic Energy Agency)