Proceedings of Information and Opinion Exchange Conference on Geoscientific Study, 2019

Nishio, Kazuhisa*; Shimizu, Mayuko; Iyatomi, Yosuke; Hama, Katsuhiro

JAEA-Review 2020-013, 59 Pages, 2020/08

JAEA-Review-2020-013.pdf:19.64MB

The Tono Geoscience Center (TGC) of Japan Atomic Energy Agency (JAEA) has been conducting geoscientific study in order to establish a scientific and technological basis for the geological disposal of HLW. Technical information of the result on the geoscientific study conducted at TGC is provided at the annual Information and Opinion Exchange Conference on Geoscientific Study of TGC for exchanging opinions among researchers and engineers from universities, research organizations and private companies. This document compiles the research presentations and posters of the conference in Mizunami on November 20, 2019.

Mizunami Underground Research Laboratory Project; Synthesis report on the R&D concerning important issues

Matsuoka, Toshiyuki; Hama, Katsuhiro

JAEA-Research 2019-012, 157 Pages, 2020/03

JAEA-Research-2019-012.pdf:11.91MB

The Mizunami Underground Research Laboratory (MIU) Project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies for geological disposal of High-level Radioactive Waste through investigations of the deep geological environment within the host crystalline rock at Mizunami City in Gifu Prefecture, central Japan. The project proceeds in three overlapping phases, "Phase I: Surface-based investigation Phase", "Phase II: Construction Phase" and "Phase III: Operation Phase". The MIU Project has been ongoing the Phase III, as the Phase II was concluded for a moment with the completion of the excavation of horizontal tunnels at GL-500m level in February 2014. The present report summarizes the research and development activities carried out mainly in the GL-500m stage during Third Medium to Long-term Research Phase.

Mizunami Underground Research Laboratory Project, Annual report for fiscal year 2017

Takeuchi, Ryuji; Iwatsuki, Teruki; Matsui, Hiroya; Nohara, Tsuyoshi; Onoe, Hironori; Ikeda, Koki; Mikake, Shinichiro; Hama, Katsuhiro; Iyatomi, Yosuke; Sasao, Eiji

JAEA-Review 2019-005, 76 Pages, 2019/06

JAEA-Review-2019-005.pdf:24.91MB

The Mizunami Underground Research Laboratory (MIU) project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of geological disposal technologies through investigations of the deep geological environment in the crystalline rock (granite) at Mizunami City, Gifu Prefecture, central Japan. On the occasion of the research program and management system revision of the entire JAEA organization in 2014, JAEA identified three remaining important issues on the geoscientific research program based on the latest results of the synthesizing research and development: "Development of countermeasure technologies for reducing groundwater inflow", "Development of modeling technologies for mass transport" and "Development of drift backfilling technologies". The research and development on three remaining important issues have been carrying out on the MIU project. In this report, the current status of the research and development activities and construction in fiscal year 2017 is summarized.

Proceedings of Information and Opinion Exchange Conference on Geoscientific Study, 2018

Nishio, Kazuhisa*; Murakami, Hiroaki; Iyatomi, Yosuke; Hama, Katsuhiro

JAEA-Review 2018-037, 53 Pages, 2019/03

JAEA-Review-2018-037.pdf:79.22MB

The Tono Geoscience Center (TGC) of Japan Atomic Energy Agency (JAEA) has been conducting geoscientific study in order to establish a scientific and technological basis for the geological disposal of HLW. Technical information of the result on the geoscientific study conducted at TGC is provided at the annual Information and Opinion Exchange Conference on Geoscientific Study of TGC for exchanging opinions among researchers and engineers from universities, research organizations and private companies. This document compiles the research presentations and posters of the conference in Mizunami on November 29, 2018.

Proceedings of Information and Opinion Exchange Conference on Geoscientific Study, 2017

Nishio, Kazuhisa*; Iyatomi, Yosuke; Hama, Katsuhiro

JAEA-Review 2017-042, 61 Pages, 2018/03

JAEA-Review-2017-042.pdf:14.42MB

The Tono Geoscience Center (TGC) of Japan Atomic Energy Agency (JAEA) has been conducting geoscientific study in order to establish a scientific and technological basis for the geological disposal of HLW. Technical information of the result on the geoscientific study conducted at TGC is provided at the annual Information and Opinion Exchange Conference on Geoscientific Study of TGC for exchanging opinions among researchers and engineers from universities, research organizations and private companies. This document compiles the research presentations and posters of the conference in Mizunami on October 31, 2017.

Mizunami Underground Research Laboratory Project; Achievement during Phase I/II and important issues for Phase III

Hama, Katsuhiro

Proceedings of 6th East Asia Forum on Radwaste Management Conference (EAFORM 2017) (Internet), 6 Pages, 2017/12

The Mizunami Underground Research Laboratory project is being pursued by the JAEA in the crystalline host rock at Mizunami City in Gifu Prefecture. The project proceeds in three overlapping phases, Surface-based investigation Phase (Phase I), Construction Phase (Phase II) and Operation Phase (III). During Phase I, a step-wise investigation was conducted by iterating investigation, interpretation, and assessment, thereby understanding of geologic environment was progressively and effectively improved with progress of investigation. During Phase II, we have evaluated adequacy of techniques for investigation, analysis and assessment of the deep geological environment established in the Phase I. For Phase III, three important issues were identified based on the latest results. Development of countermeasure technologies for reducing groundwater inflow, Development of modeling technologies for mass transport, Development of drift backfilling technologies.

Diffusion experiment using block sample of the Toki granite

Hama, Katsuhiro; Iwasaki, Riyo*; Morikawa, Keita*

JAEA-Technology 2017-015, 45 Pages, 2017/07

JAEA-Technology-2017-015.pdf:16.57MB

Tono Geoscience Center of Japan Atomic Energy Agency has been carrying out the Mizunami Underground Research Laboratory Project. The goal of mass transport study is to obtain a better understanding of mass transport phenomena in the geological environment as well as to develop technologies for measurement of the mass transport parameters, model construction, numerical analysis and validation of those technologies. This experiment was planned to understand the influence of the microscopic structure in the rock mass on the mass transport property. The diffusion experiment using rock sample was carried out. The macroscopic and microscopic observations were carried out to understand the distribution of tracer (uranine) after the diffusion experiment. The uranine was observed in the plagioclase, in the grain boundary and in the microfracture in the mineral grains. These results suggested that distribution of mineral and of microfracture could affect the diffusion property of uranine.

Mizunami Underground Research Laboratory Project, Annual report for fiscal year 2015

Hama, Katsuhiro; Iwatsuki, Teruki; Matsui, Hiroya; Mikake, Shinichiro; Ishibashi, Masayuki; Onoe, Hironori; Takeuchi, Ryuji; Nohara, Tsuyoshi; Sasao, Eiji; Ikeda, Koki; et al.

JAEA-Review 2016-023, 65 Pages, 2016/12

JAEA-Review-2016-023.pdf:47.32MB

The Mizunami Underground Research Laboratory (MIU) project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of geological disposal technologies through investigations of the deep geological environment in the crystalline host rock (granite) at Mizunami City in Gifu Prefecture, central Japan. On the occasion of the reform of the entire JAEA organization in 2014, JAEA identified three important issues on the geoscientific research program: "Development of countermeasure technologies for reducing groundwater inflow", "Development of modelling technologies for mass transport" and "Development of drift backfilling technologies", based on the latest results of the synthesizing research and development (R&D). These R&D on three important issues have been carrying out on the MIU project. In this report, the current status of R&D activities and construction in 2015 is summarized.

Cross-checking groundwater age by He and C dating in a granite, Tono area, central Japan

Hasegawa, Takuma*; Nakata, Kotaro*; Tomioka, Yuichi*; Goto, Kazuyuki*; Kashiwaya, Koki*; Hama, Katsuhiro; Iwatsuki, Teruki; Kunimaru, Takanori*; Takeda, Masaki

Geochimica et Cosmochimica Acta, 192, p.166 - 185, 2016/11

https://doi.org/10.1016/j.gca.2016.07.013

Groundwater dating was performed simultaneously by the He and C methods in granite of the Tono area in central Japan. Groundwater was sampled at 30 packed-off sections of six 1000-m boreholes. He concentrations increased and C concentrations decreased along a groundwater flow path on a topographic gradient. He ages were calculated by using the in situ He production rate derived from the porosity, density, and U and Th content of the rock, neglecting external flux. The linear relation between the He ages and the noncorrected C ages, except in the discharge area. Simultaneous measurements make it feasible to estimate the accumulation rate of He and initial dilution of C, which cannot be done with a single method. Cross-checking groundwater dating has the potential to provide more reliable groundwater ages.

Mizunami Underground Research Laboratory Project, Plan for fiscal year 2016

Hama, Katsuhiro; Takeuchi, Ryuji; Iwatsuki, Teruki; Sasao, Eiji; Mikake, Shinichiro; Ikeda, Koki; Matsui, Hiroya; Osawa, Hideaki

JAEA-Review 2016-015, 29 Pages, 2016/07

JAEA-Review-2016-015.pdf:3.41MB

The Mizunami Underground Research Laboratory (MIU) project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of geological disposal technologies through investigations of the deep geological environment in the crystalline host rock (granite rock) at Mizunami City in Gifu Prefecture, central Japan. On the occasion of the reform of the entire JAEA organization in 2014, JAEA identified three important issues on the geoscientific research program: "Development of countermeasure technologies for reducing groundwater inflow", "Development of modelling technologies for mass transport" and "Development of drift backfilling technologies", based on the latest results of the synthesizing research and development (R&D). These R&D on three remaining important issues have been carrying out on the MIU project. This report summarizes the R&D activities planned for fiscal year 2016 based on the MIU Master Plan updated in 2015 and so on.