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Takeuchi, Ryuji; Mikake, Shinichiro; Ikeda, Koki; Nishio, Kazuhisa*; Kokubu, Yoko; Hanamuro, Takahiro
JAEA-Review 2023-007, 114 Pages, 2023/07
JAEA-Review-2023-007.pdf:12.02MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center has been conducting the Mizunami Underground Research Laboratory (MIU) Project 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 since fiscal year 1996. Backfilling and restoration works in the MIU site have been being conducted based on "the MIU Project from FY2020 onwards" which is defined the way forward of backfilling and restoration works and environmental monitoring investigations in the MIU site, since fiscal year 2020. This report summarizes the outline, process, and achievements of the construction and the safety patrol of the backfilling and restoration works in the MIU site performed from May 16, 2020 to January 16, 2022.
Nishio, Kazuhisa*; Hanamuro, Takahiro; Mikake, Shinichiro
JAEA-Review 2022-019, 42 Pages, 2022/08
JAEA-Review-2022-019.pdf:8.26MB
Research and development project, Mizunami Underground Research Laboratory (MIU) Project at the Tono Geoscience Center (TGC) of Japan Atomic Energy Agency (JAEA), has been performed since 1996 and ended in 2019 fiscal year. On January 14, 2022, construction work such as backfilling of the research tunnels of the MIU was also successfully completed. After the research results has been compiled, we decided to hold a final debriefing session to report the research results obtained from the project and the construction details such as backfilling of the tunnels. This report summarized the presentation materials used in "The Final Debriefing Session on the Mizunami Underground Research Laboratory Project" held on February 9, 2022.
Onoe, Hironori; Takeuchi, Ryuji
JAEA-Data/Code 2020-010, 112 Pages, 2020/10
JAEA-Data-Code-2020-010.pdf:6.22MB
JAEA-Data-Code-2020-010-appendix1(DVD-ROM).zip:169.12MBJAEA-Data-Code-2020-010-appendix2(DVD-ROM).zip:338.45MBJAEA-Data-Code-2020-010-appendix3(DVD-ROM).zip:448.05MB
The Mizunami Underground Research Laboratory (MIU) Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III), the project is being carried out under the Phase III. The main goals of the MIU Project from Phase I to Phase III are: to establish techniques for investigation, analysis and assessment of the deep geological environment, and to develop a base of engineering for deep underground application. One of the Phase III goals is to construct geological environment models and grasp deep geological changes when expanding the research gallery by research and investigations using research galleries. The long term hydro-pressure monitoring has been continued to achieve the Phase III goals. Furthermore, these monitoring were ceased at the end of FY2019 due to the completion of the MIU project. This report describes the results of the long term hydro-pressure monitoring from April 2017 to March 2020.
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.
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.
Iwasaki, Riyo*; Hama, Katsuhiro; Morikawa, Keita*; Hosoya, Shinichi*
JAEA-Technology 2016-037, 62 Pages, 2017/02
JAEA-Technology-2016-037.pdf:8.69MB
Mass transport study is mainly performed as part of Phase III in the Mizunami Underground Research Laboratory Project. In Phase III, 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 study was planned to understand the influence of the geological characteristics of fracture on the mass transport parameters.
Hama, Katsuhiro; Sasao, Eiji; Iwatsuki, Teruki; Onoe, Hironori; Sato, Toshinori; Fujita, Tomoo; Sasamoto, Hiroshi; Matsuoka, Toshiyuki; Takeda, Masaki; Aoyagi, Kazuhei; et al.
JAEA-Review 2016-014, 274 Pages, 2016/08
JAEA-Review-2016-014.pdf:44.45MB
We synthesized the research results from the Mizunami/Horonobe Underground Research Laboratories (URLs) and geo-stability projects in the second midterm research phase. This report can be used as a technical basis for the Nuclear Waste Management Organization of Japan/Regulator at each decision point from siting to beginning of disposal (Principal Investigation to Detailed Investigation Phase).
Hama, Katsuhiro
JAEA-Data/Code 2016-006, 23 Pages, 2016/07
JAEA-Data-Code-2016-006.pdf:1.6MB
The Mizunami Underground Research Laboratory project is being pursued by the Japan Atomic Energy Agency to enhance the reliability of relevant disposal technologies 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, Surface-based investigation Phase, Construction Phase and Operation Phase. The MIU Project has been ongoing the Phase III. As a part of the Phase III investigation, evaluation of mass transport property using natural Uranium-series and Thorium-series nuclides has been carried out. In this report, the compilation of existing data and preliminary evaluation was carried out.
Hama, Katsuhiro; Iwatsuki, Teruki; Matsui, Hiroya; Mikake, Shinichiro; Sasao, Eiji; Osawa, Hideaki
JAEA-Review 2016-004, 38 Pages, 2016/06
JAEA-Review-2016-004.pdf:7.07MB
The Mizunami Underground Research Laboratory project is being pursued by the Japan Atomic Energy Agency to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host crystalline rock at Mizunami City in Gifu Prefecture, central Japan. The present report summarizes the research and development activities planned mainly in the -500m gallery.
Ueno, Tetsuro; Takeuchi, Ryuji
JAEA-Data/Code 2015-031, 61 Pages, 2016/03
JAEA-Data-Code-2015-031.pdf:9.15MBJAEA-Data-Code-2015-031-1appendix(DVD-ROM).zip:174.29MBJAEA-Data-Code-2015-031-2-1appendix(DVD-ROM).zip:86.67MBJAEA-Data-Code-2015-031-2-2appendix(DVD-ROM).zip:268.33MBJAEA-Data-Code-2015-031-2-3appendix(DVD-ROM).zip:569.4MBJAEA-Data-Code-2015-031-2-4appendix(DVD-ROM).zip:103.25MBJAEA-Data-Code-2015-031-2-5appendix(DVD-ROM).zip:0.4MB
Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has carried out the subsurface water balance observation in order to estimate groundwater recharge rate for setting the upper boundary conditions on groundwater flow simulation and to obtain data for calibration of hydrogeological model. In the subsurface water balance observations, meteorogical data, river flow rate, groundwater level and soil moisture have been observed in the Shoma River watershed, the Shoma River model watershed and the MIU Construction Site. After missing or abnormal data in the monitoring data from the fiscal year 2014 were complemented or corrected, the data were compiled in data set. Furthermore the groundwater recharge rates in the Hazama River watershed were calculated using the river flow rate data obtained from the environment survey in the MIU construction work in the fiscal year 2014. Because many data were accumulated, these observations were finished in the end of March, 2015.
Onoe, Hironori; Saegusa, Hiromitsu; Takeuchi, Ryuji
Doboku Gakkai Rombunshu, C (Chiken Kogaku) (Internet), 72(1), p.13 - 26, 2016/01
The Japan Atomic Energy Agency is conducting the Mizunami Underground Research Laboratory (URL) project in Mizunami, Gifu, in order to establish scientific and technical basis for geological disposal of high-level radioactive waste. This paper comprehensively describes the result of groundwater flow modeling using data of hydraulic responses and hydrochemical changes due to URL construction. Technical know-how and methodology of hydrogeological monitoring and groundwater flow modeling were presented for characterization of hydraulic heterogeneities in fractured crystalline rock. Furthermore, effectivity of data acquisition of hydrochemical changes in groundwater for validation of result of groundwater flow modeling was indicated.
Saegusa, Hiromitsu; Onoe, Hironori; Ishibashi, Masayuki; Tanaka, Tatsuya*; Abumi, Kensho*; Hashimoto, Shuji*; Bruines, P.*
JAEA-Research 2015-011, 59 Pages, 2015/10
JAEA-Research-2015-011.pdf:49.44MB
It is important to evaluate groundwater flow characteristics on several spatial scales for assessment of long-term safety on geological disposal of high-level radioactive wastes. An estimation of hydraulic heterogeneity caused by fracture network is significant for evaluation of the groundwater flow characteristics in the region of tens of meters square. Heterogeneity of equivalent hydraulic properties is needed to estimate for evaluation of the groundwater flow characteristics in the region of several km square. In order to develop the methodology for multi-scale hydrogeological modeling taking into account the hydraulic heterogeneity, spatial distribution of fractures and their hydraulic properties have been modeled using discrete fracture network (DFN) model. Then, hydrogeological continuum model taking into account the hydraulic heterogeneity has been estimated based on the DFN model. Through this study, the methodology for multi-scale hydrogeological modeling according to type of investigation data has been proposed.
Onoe, Hironori; Kosaka, Hiroshi*; Takeuchi, Ryuji; Saegusa, Hiromitsu
JAEA-Research 2015-008, 146 Pages, 2015/08
JAEA-Research-2015-008.pdf:76.46MB
Mizunami Underground Research Laboratory (MIU) Project is being carried out by Japan Atomic Energy Agency (JAEA) in the Cretaceous Toki granite in the Tono area, central Japan. The MIU Project has three overlapping phases: Surface-based Investigation (Phase I), Construction (Phase II) and Operation (Phase III). In this study, calibration of hydrogeological model and groundwater flow simulation using the data obtained by the Phase I and Phase II were carried out in order to develop the methodology for construction and update of hydrogeological model on Site Scale. As a result, hydrogeological model on Site Scale, which is able to simulate comprehensively the obtained data regarding groundwater pressure distribution before excavation of the MIU facilities, hydraulic responses and inflow volume during excavation of the MIU facilities, was constructed.
Koide, Kaoru; Osawa, Hideaki; Ito, Hiroaki; Tanai, Kenji; Semba, Takeshi; Naito, Morimasa; Sugihara, Kozo; Miyamoto, Yoichi
Annual Waste Management Symposium (WM 2015), Vol.5, p.3631 - 3645, 2015/00
JAEA has promoted R&D on HLW geological disposal technology. JAEA launched the Mizunami and the Horonobe URL Projects to cover the diversity of geological environments in Japan. The Mizunami URL Project is a geoscientific research project in the crystalline rock environment. The Horonobe URL Project consists of geoscientific studies and R&D on geological disposal technology in the sedimentary rock environment. Both URL projects have been planned to proceed in three overlapping phases, Surface-based investigation Phase, Construction Phase and Operation Phase. Currently, the construction of research galleries in both of the Mizunami and the Horonobe URLs has been completed to 500 m and 350 m depths, respectively. JAEA will promote R&D activities in Phase III including study of the long-term evolution of the geological environment, and contribute to international cooperation, development of human resources and communication amongst stakeholders through both URL projects.
Kawamoto, Koji; Kuboshima, Koji*; Murakami, Hiroaki; Ishibashi, Masayuki; Sasao, Eiji
JAEA-Research 2014-021, 30 Pages, 2014/11
JAEA-Research-2014-021.pdf:6.79MB
The MIU (Mizunami Underground Research Laboratory) Project has three overlapping phases, Surface-based investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). Currently, the project is under Phase II and Phase III. One of Phase II goals is set up to develop and revise models of the geological environment using the investigation results obtained during excavation, and to determine and assess changes in the geological environment in response to excavation. This report aims at compiling results of study on geology and geological structure at the -500m Stage in the MIU construction site, investigated in the Phase II and provides the fundamental information on the geology and geological structure for future study and modeling of geological environment.
Hama, Katsuhiro
no journal, ,
The development of modeling methodology for the mass transport in the geological environment is one of the important issues in the Mizunami Underground Research Laboratory Project. The main goal of this issue is to develop methodology for the characterization of mass transport property in the fractured crystalline rock. To achieve this goal, the study concerning mass transport phenomena in the Toki Granite should be carried out. The current status of this study has been presented.
Hama, Katsuhiro
no journal, ,
The Mizunami Underground Research Laboratory project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host crystalline rock at Mizunami City in Gifu Prefecture, central Japan. The project has been ongoing the operation phase. The present report summarizes the achievement of the research and development activities.
Hama, Katsuhiro; Ishibashi, Masayuki; Tanaka, Yasuharu*
no journal, ,
Tono Geoscience Center of Japan Atomic Energy Agency has been carrying out the Mizunami Underground Research Laboratory Project. This project has three overlapping phases: Surface-based investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). Currently, the project is being carried out under the Phase III. The development of mass transport modeling methodology is one of the important issues in the Phase III investigation. This report presents the status and future plan for this study.
Sasao, Eiji
no journal, ,
The research status of geoscientific study, Mizunami Underground Research Laboratory project, geosphere stability for long-term isolation and geochronology are given lectures as the invited lectures of the 128th lecture of the Japan Geodetic Society.
Ishibashi, Masayuki
no journal, ,
Fractures in crystalline rock, such as granite, function as pathways for groundwater flow and mass transport. Understanding characteristics and long term behavior of fracture with groundwater inflow is important for evaluation of transfer the dissolved matter in groundwater. Therefor this paper describes the features of WCFs (water conducting fractures), the long-term behavior and the investigations. Result of detailed gallery wall mapping and borehole investigations at the ground level -300 m and -500m galleries in the Mizunami Underground Research Laboratory clarify that WCFs are is characterized by its occupy approximate 10 percent of all observed fractures, the size is relatively large and the fillings have layer structure including calcite.
