*Kazuya Miyakawa¹, Hisashi Imai², Satoru Hirai², Hirokazu Ohno¹, Kotaro Nakata³, Takuma Hasegawa³ (1.Japan Atomic Energy Argency, 2.Ando Hazama Corporation, 3.Central Research Institute of Electric Power Industry)

*Hiroki Nishimura^1,2, Mariko Kouduka¹, Akari Fukuda¹, Toyoho Ishimura³, Yuki Amano^5,4, 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)