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Yamaguchi, Masaaki; Suzuki, Yuji*; Kabasawa, Satsuki; Kato, Tomoko
JAEA-Data/Code 2024-001, 21 Pages, 2024/03
JAEA-Data-Code-2024-001.pdf:3.45MB
JAEA-Data-Code-2024-001-appendix(CD-ROM).zip:8.0MB
Model catchments have developed for use in testing various assessment models that can consider specific surface environmental conditions such as topography, riverine systems, and land use in the biosphere assessment of HLW geological disposal. The model catchments consist of the topography and riverine system of the catchment area created using existing tools, as well as land use and population distribution, river discharge, sediment flux data set by algorithms from topographical data. Datasets of three types of model watersheds (Types 1 to 3, watershed area: 730 to 770 km
) with different topographical characteristics have released as raster data that can be handled by geographic information systems (GIS). Since the model catchments were created virtually reflecting as much as possible the main characteristics of Japan's surface environment, they can be used as a test bed for conducting hydraulic/mass transport analysis to set the GBI and compartment model.
Takeuchi, Ryuji; Kokubu, Yoko; Nishio, Kazuhisa*
JAEA-Data/Code 2023-014, 118 Pages, 2024/02
JAEA-Data-Code-2023-014.pdf:4.77MBJAEA-Data-Code-2023-014-appendix(CD-ROM).zip:249.03MB
The Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has been conducting the groundwater pressure and hydro-chemical monitoring to confirm the restoration process of the surrounding geological environment associated with the backfilling of shafts and tunnels of Mizunami Underground Research Laboratory (MIU). This report summarizes the data of the groundwater pressure and hydro-chemical monitoring from boreholes and forth at and around the MIU conducted in FY2022. In addition, unreported hydro-chemical monitoring data from the boreholes and forth at the MIU conducted in FY2021 were also compiled.
Aoyagi, Kazuhei; Ishii, Eiichi
Environmental Earth Sciences, 83(3), p.98_1 - 98_15, 2024/02
Times Cited Count：0 Percentile：0.04(Environmental Sciences)The long-term geological disposal of high-level radioactive waste relies on predictions of future changes in a disposal facility's hydro-mechanical characteristics to assess potential leakage through fractures in the excavation damaged zone (EDZ) after backfilling the facility. This study evaluated the transmissivity of EDZ fractures using in situ hydraulic tests around the area of a full-scale, experimental, engineered barrier system in the Horonobe Underground Research Laboratory, Hokkaido, Japan. After their installation, the buffer blocks swelled, altering the stresses within the EDZ fractures. The effects of these changing stresses on the fractures' transmissivity were assessed over a period of 4 years. The transmissivity continuously decreased in this period to about 41% of its value measured prior to the swelling. Using the Barton-Bandis normal-stress-dependent fracture-closure model, the decrease in transmissivity is quantitatively attributed to closure of the EDZ fractures, which was caused by the swelling pressure increasing up to 0.88 MPa. Evidence of fracture closure came from seismic tomography surveying, which revealed a slight increase in seismic velocity in the study area with increasing swelling pressure. The results show that EDZ fractures were closed by swelling of the full-scale buffer material. They also demonstrate the applicability of the Barton-Bandis model to preliminary estimation of the long-term transmissivity of EDZ fractures in facilities for the geological disposal of radioactive waste.
Takeuchi, Ryuji; Nishio, Kazuhisa*; Kokubu, Yoko
JAEA-Data/Code 2023-013, 74 Pages, 2024/01
JAEA-Data-Code-2023-013.pdf:4.2MB
The Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has been conducting the environmental monitoring investigation to confirm the environmental impacts associated with the backfilling of shafts and tunnels at the Mizunami Underground Research Laboratory (MIU). This report summarizes the results of the environmental impact investigations conducted as part of the environmental monitoring investigation around the MIU Site in FY2022, which include groundwater level measurement in wells, river flow rate measurement, water analysis of Hazama river, noise and vibration surveys, and soil survey.
Matsueda, Makoto
Chino To Joho, 35(4), P. 88, 2023/11
Radioactive waste is what contains radioactive materials generated through nuclear activities, radiopharmacy, research and development. The treatment and disposal of the waste are one of the key challenges facing people. This glossary describes the classification of radioactive waste, the challenges and the current efforts of its disposal and current efforts, and so on.
Tachi, Yukio
Kagaku To Kyoiku, 71(10), p.420 - 423, 2023/10
no abstracts in English
Sato, Hisashi*; Takayama, Yusuke; Suzuki, Hideaki*; Sato, Daisuke*
JAEA-Data/Code 2023-010, 47 Pages, 2023/09
JAEA-Data-Code-2023-010.pdf:1.45MB
When a high-level radioactive waste repository is constructed in a coastal area, it is necessary to fully evaluate the impact of seawater-based groundwater on engineered barriers, including buffer materials. In this report, one-dimensional saltwater infiltration tests were conducted to obtain data to understand the impact of seawater-based groundwater on the migration phenomena of water and solutes in the buffer material during the transient period. As a result, it was confirmed that the infiltration rate increased as the NaCl concentration in the infiltration solution increased. And it was confirmed that the water content ratio distribution changed as the NaCl concentration in the infiltration solution increased. As a result of analysis of the chloride ion concentration of the post-test specimens confirmed that chloride ion enrichment was occurred with infiltration. As a result of verifying the mechanism by which chloride ion enrichment occurs, it was confirmed that the phenomenon of chloride ion enrichment due to infiltration depends on the initial water content ratio.
Osawa, Hideaki
Gijutsushi "Chubu", (12), p.34 - 41, 2023/09
This introduces current status of Toki Geochronology Research Laboratory, Tono Geoscience Center, Japan Atomic Energy Agency.
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.
Takeuchi, Ryuji; Nishio, Kazuhisa*; Hanamuro, Takahiro; Kokubu, Yoko
JAEA-Data/Code 2022-010, 110 Pages, 2023/03
JAEA-Data-Code-2022-010.pdf:6.2MB
The Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has been conducting the environmental monitoring investigation to confirm the environmental impacts associated with the backfilling of shafts and tunnels at the Mizunami Underground Research Laboratory (MIU). This report summarizes the results of environmental impact investigations conducted as part of the environmental monitoring investigation around the MIU Site from FY2020 to FY2021, which include groundwater level measurement in wells, river flow rate measurement, water analysis of Hazama river, noise and vibration surveys, and soil survey.
Mitsui, Seiichiro
Kinzoku, 93(3), p.211 - 218, 2023/03
As part of research and development of geological disposal, "natural analogues" have been applied to validate concept of models and evaluation methodologies for performance assessment. By introducing our research results on natural analogues, this paper presents how we have utilized knowledge of excavated archaeological artifacts for geological disposal studies.
Yanagida, Akinobu*; Ura, Yoko*; Mitsui, Seiichiro; Ishidera, Takamitsu; Kawakita, Ryohei
Nara Bunkazai Kenkyujo Soritsu 70-Shunen Kinen Rombunshu; Bunkazai Ronso 5, p.843 - 856, 2023/03
To investigate chloride salt accumulation inside an iron artifact in soil, non-destructive analysis of three iron artifacts excavated from the Heijo Palace Site was conducted using elemental mapping by X-ray fluorescence analysis, micro-X-ray diffraction analysis, and X-ray computed tomography. Furthermore, the buried environments of the artifacts were presumed based on the previous reports of the environmental investigation at the Heijo Palace site. The results revealed the iron artifact's corrosion behavior was different individually- (1) the iron artifact that was presumed buried under oxidation environments had a goethite/magnetite corrosion layer and contained akageneite inside the corrosion layer. (2) the metal of the other iron artifacts buried under the oxidation environment had eluted absolutely and the artifacts had a rust layer formed by only goethite. (3) the other artifact buried in reduction environments had a rust layer composed of siderite. Accumulation of chloride salts inside an iron artifact was observed only in (1). Because each Cl
concentration measured in underground water observation holes at the Heijo Palace Site showed almost the same level concentrations, it was presumed that the accumulation of chloride salts depended on the environmental factor except for Cl concentration. Based on these results, there was a possibility that the occurrence of local corrosion attributed to the separation of anodic and cathodic regions through the formation of the goethite/magnetite rust layer caused chloride salts accumulation inside an iron artifact.
Takeuchi, Ryuji; Murakami, Hiroaki; Nishio, Kazuhisa*
JAEA-Data/Code 2022-008, 184 Pages, 2023/01
JAEA-Data-Code-2022-008.pdf:8.2MBJAEA-Data-Code-2022-008-appendix1(DVD-ROM).zip:327.79MBJAEA-Data-Code-2022-008-appendix2(DVD-ROM).zip:284.46MB
The Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has been conducting the groundwater pressure and hydro-chemical monitoring to confirm the restoration process of the surrounding geological environment associated with the backfilling of shafts and tunnels of Mizunami Underground Research Laboratory. This report summarizes the results of the groundwater pressure and hydro-chemical monitoring conducted from FY2020 to FY2021.
Geological Disposal Research and Development Department
JAEA-Evaluation 2022-007, 81 Pages, 2022/11
JAEA-Evaluation-2022-007.pdf:2.06MBJAEA-Evaluation-2022-007-appendix(CD-ROM).zip:37.06MB
Japan Atomic Energy Agency (JAEA) consulted the advisory committee, "Evaluation Committee on Research and Development (R&D) Activities for Geological Disposal of High-Level Radioactive Waste", for post- and pre-review assessment of R&D activities on high-level radioactive waste disposal in accordance with "General Guideline for the Evaluation of Government Research and Development (R&D) Activities" by the Cabinet Office, Government of Japan, "Guideline for Evaluation of R&D in Ministry of Education, Culture, Sports, Science and Technology" and JAEA's "Regulation on Conduct for Evaluation of R&D Activities". In response to JAEA's request, the Committee reviewed mainly the progress of the R&D project on geological disposal, the relevance of the project outcome and the efficiency of the project implementation during the period of the current and next plan. This report summarizes the results of the assessment by the Committee with the Committee report attached.
Makino, Hitoshi; Semba, Takeshi; Shibata, Masahiro
NEA/RWM/R(2018)7 (Internet), p.315 - 322, 2022/11
This presentation summarize challenge on development of an advanced KMS by JAEA including the background to this initiative, the basic approach selected, a developed prototype of the JAEA KMS, and challenges and practical issues for introduction and also sustainable maintenance of the JAEA KMS.
Murakami, Hiroaki; Takeuchi, Ryuji; Iwatsuki, Teruki
JAEA-Technology 2022-022, 34 Pages, 2022/10
JAEA-Technology-2022-022.pdf:3.47MB
Japan Atomic Energy Agency (JAEA) has been conducting the hydro-pressure and hydrochemical monitoring for more than two decades to understand the hydrochemical disturbance due to the excavation of tunnels at Mizunami Underground Research Laboratory (MIU). To understand the environmental influence due to the backfilling of research tunnels that started in 2019, environmental monitoring of groundwater has been performed and recovery status of groundwater is being confirmed. In order to observe the deep-groundwater environment from the ground, the groundwater pressure monitoring and sampling, which have been performed in the research tunnel, are to be performed from the ground. However, backfilling of a large-scale underground facilities such as MIU is globally unprecedented, thus it was necessary to develop a new observation system. Accordingly, we developed a new observation network to observe the environment around the research tunnels of the MIU. This system enables monitoring of groundwater pressure and water sampling of the backfilled tunnel from the ground while utilizing the existing-monitoring system installed in the tunnels. Accordingly, we demonstrated its technology through the environmental monitoring of groundwater. The results of the environmental monitoring and the existing groundwater data of MIU indicate that this system is able to monitor the groundwater environment in the backfilled tunnels.
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.
Yamaguchi, Masaaki
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 29(1), p.38 - 41, 2022/06
This presentation outlined the framework and background of Japan's geological disposal research that has been underway since the 1970s and outlined research and development on the engineering technology of geological disposal and the performance assessment of geological disposal systems in the research and development fields. Specific assessment methods used in both R & D fields and recent research topics were also explained.
Sugihara, Kozo
JAEA-Review 2022-006, 74 Pages, 2022/05
JAEA-Review-2022-006.pdf:7.09MB
As a trial to show the history of Tono Mine, this report summarizes the abstracts of literature, which is hit in the JAEA Originated Papers Searching System (JOPSS) referred with a word of "Tono Mine", in time order. 214 JAEA Reports, 54 papers and 9 oral presentations have been hit with free-word search using a word of "Tono Mine" in the JOPSS on February 1st, 2022. This report summarizes the abstracts of JAEA Reports mainly, as JAEA Reports are prepared in each activity in the mine. However there are few JAEA Reports of uranium exploration, some reports can be found out in the JOPSS and describe the history of uranium exploration activities in and around the Tono Mine. Histories of the Power Reactor and Nuclear Fuel Development Corporation also contain some descriptions and chronological tables relating to the Tono Mine. The extracts of these reports and histories are shown in this report as the history of Tono Mine during the time of uranium exploration.
Osawa, Hideaki; Matsui, Hideki
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 28(2), p.18 - 25, 2021/12
The Japan Atomic Energy Agency had offered visitor's tour to the underground and surface facilities of the Mizunami Underground Research Laboratory (URL) at the Tono Geoscience Center in order to promote the understanding of the R&D of geological disposal technology and geological disposal for the public. We analyzed questionnaires distributed after visiting these facilities from FY2010 to FY2019, except for FY2016, in the hopes of using risk communication for geological disposal. Results suggest that visiting these facilities is a valuable experience to understand geological disposal because some people, knew even just a little bit about it, have positively evaluated appropriateness of geological disposal by a tour of the Mizunami URL. While some people who have negatively evaluated safety of geological disposal are highly interested in issues of nuclear power and site selection, some people who have positively evaluated safety of geological disposal are highly interested in public understanding of geological disposal. Furthermore, both these groups believe that long-term safety is a technical issue.
