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He and 
C dating in a granite, Tono area, central JapanHasegawa, 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
Times Cited Count：10 Percentile：38.79(Geochemistry & Geophysics)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.
Hama, Katsuhiro; Sato, Toshinori; Sasao, Eiji; Iwatsuki, Teruki; Kunimaru, Takanori; Matsuoka, Toshiyuki; Takeuchi, Ryuji; Onoe, Hironori; Mikake, Shinichiro
JAEA-Data/Code 2013-010, 58 Pages, 2013/10
JAEA-Data-Code-2013-010.pdf:14.94MB
JAEA at Tono Geoscience Center is pursuing a geoscientific research and development project namely the Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment to construct scientific and technological basis for geological disposal of High-level Radioactive Waste. The MIU project is planned in three overlapping phases; Surface-based Investigation Phase (Phase I), Construction Phase (Phase II) and Operation Phase (Phase III). Currently, the project is under the Phase II and Phase III. In Phase II, adequacy of geological environment model is evaluated. Applicability and feasibility assessment of various elemental technologies adopted to characterize geological environment in Phase I will be evaluated. Furthermore, from a design, construction and safety assessment point of view, a series of evaluation procedures are organized and Geosynthesis Data Flow Diagram is established. This is the integrated data flow from investigation through modeling and analysis. It proposes the rational combinations of investigation items which make the investigation results reflect the safety assessment and designing. In this sense, Geosynthesis Data Flow Diagram indicates the rational framework, from investigation to modeling and analysis, for achieving individual goals and tasks. This report summarizes the Geosynthesis Data Flow Diagram optimized during Phase II investigation. The Geosynthesis Data Flow Diagram will be revised based on the research progress.
Kunimaru, Takanori; Mikake, Shinichiro; Nishio, Kazuhisa; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Ishibashi, Masayuki; Sasao, Eiji; Hikima, Ryoichi; Tanno, Takeo; Sanada, Hiroyuki; et al.
JAEA-Review 2013-018, 169 Pages, 2013/09
JAEA-Review-2013-018.pdf:15.71MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is pursuing a geoscientific research and development project namely the Mizunami Underground Research Laboratory (MIU) Project in crystalline rock environment in order to construct scientific and technological basis for geological disposal of High-level Radioactive Waste (HLW). The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). The MIU Project has been ongoing the Phase II and the Phase III in 2011 fiscal year. This report shows the results of the investigation, construction and collaboration studies in fiscal year 2011, as a part of the Phase II and Phase III based on the MIU Master Plan updated in 2010.
Yokota, Hideharu; Amano, Kenji; Maekawa, Keisuke; Kunimaru, Takanori; Naemura, Yumi*; Ijiri, Yuji*; Motoshima, Takayuki*; Suzuki, Shunichi*; Teshima, Kazufumi*
JAEA-Research 2013-002, 281 Pages, 2013/06
JAEA-Research-2013-002.pdf:13.03MB
To evaluate permeable heterogeneity in a fracture and scale effects which are problems to be solved based on the 
mass transportation data of fractures in hostrock, a number of tracer tests are simulated in a fictitious single plate fracture generated on computer in this study. And the transport parameters, e.g. longitudinal dispersion length, true velocity and dilution rate, are identified by fitting one- and two-dimensional models to the breakthrough curves obtained from the simulations in order to investigate the applicability of these models to the evaluation of tracer test. As a result, one-dimensional model yields larger longitudinal dispersion length than two-dimensional model in the both cases of homogeneous and heterogeneous hydraulic conductivity fields of the fictitious fracture. And, the longitudinal dispersion length identified from a tracer test is smaller and/or larger than the macroscopic longitudinal dispersion length identified from whole fracture. It is clarified that these are occurred by shorter or longer distance between boreholes compare to the correlation length of geostatistical heterogeneity of fictitious fracture.
Yuguchi, Takashi; Ishibashi, Masayuki; Morikawa, Keita; Kunimaru, Takanori
JAEA-Data/Code 2013-004, 38 Pages, 2013/06
JAEA-Data-Code-2013-004.pdf:15.49MB
Tono Geoscientific Research Unit of Japan Atomic Energy Agency (JAEA) is carrying out the Underground Research Laboratory Project, which is a scientific study revealing the deep geological environment as a basis of research and development for geological disposal of high level radioactive wastes. Nowadays, the project is under the Phase II and Phase III. In the 2011 fiscal year, rock specimens accompanied with grout-filling fracture were collected from -300m Access / Research Gallery of the Mizunami Underground Research Laboratory Construction Site, which were processed into thin sections, and then observed through polarizing microscopy. The grout-filling fracture can be identified as groundwater flow path and thus mass transfer pathway. Investigation methodology and petrological / mineralogical data are basic information for the study of mass transfer in Phase III. This paper presents sampling procedure of rock specimen accompanied with grout-filling fracture and compiles the results of these petrographical observations and analyses.
Doughty, C.*; Tsang, C.-F.*; Yabuuchi, Satoshi; Kunimaru, Takanori
Journal of Hydrology, 482, p.1 - 13, 2013/03
Times Cited Count：16 Percentile：51.79(Medical Informatics)To improve the field method to provide heterogenety data for modeling of solute transport in complex fractured rock, the analysis of the flowing fluid electric conductivity(FFEC) logging was examined. FFEC logging was conducted in the pilot borehole in fractured sedimentary rock in Japan as part of the Horonobe Underground Research Laboratory Project. FFEC logs were collected under unpumped conditions and at two different pumping rates, nominally 8L/min and 16L/min. Though the data have a number of complications, the analysis was successful to identify 17 hydraulically conducting fractures, and to estimate their hydraulic transimissivities, inherent pressure heads and salinities (in terms of fluid electric conductivities). The results are confirmed in comparison with hydraulic packer tests and hydrochemical data.
Iwatsuki, Teruki; Mizuno, Takashi; Kunimaru, Takanori; Amano, Yuki; Matsuzaki, Tatsuji; Semba, Takeshi
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 19(2), p.51 - 63, 2012/12
Various engineers from different generations concern with geological disposal project of high-level radioactive waste (HLW) over time. It requires to manage information to ensure the traceability of the decision making process and the inheritance of technique involved in project management. We developed Expert system available on the web to manage inheritable knowledge related to procedure, know-how and the notice of investigation techniques for deep geological environment. This report provides an overview of expert system and the one of contents regarding hydrochemical modeling and the updating method in literature survey stage 
detail investigation stage of geological disposal project.
Komatsu, Mitsuru*; Nishigaki, Makoto*; Seno, Shoji*; Hirata, Yoichi*; Takenobu, Kazuyoshi*; Tagishi, Hirotaka*; Kunimaru, Takanori; Maekawa, Keisuke; Yamamoto, Yoichi; Toida, Masaru*; et al.
JAEA-Research 2012-001, 77 Pages, 2012/09
JAEA-Research-2012-001.pdf:4.85MB
This research focused on methods of estimating the amounts of groundwater recharge, which are normally required as upper boundary conditions in groundwater flow analyses, based on measurements of infiltrating water in the ground, to systematize the methods and establish systems which are stable and measurable on site over a long time. Regarding developing measurement systems, fiber-optic strain measurement methods that enable multiple-point and long-distance measurement were used for measuring three quantities: suction pressure, soil moisture and volumetric water content rate obtained by applying water absorption swelling material, and each measurement was discussed. The results showed that the fiber-optic soil aquameter has two types of practical application: one for measuring suction pressure (Type I), and the other for measuring volumetric water content rate obtained by applying water absorption swelling material (Type III). Furthermore, by using measurement instruments in actual fields, the validity of the two methods for estimating the rainfall infiltration capacities of shallow-layer soils, that is, estimating the capacities either directly by measurements of soil water or from unsaturated hydraulic conductivities, was confirmed.
Kunimaru, Takanori; Mikake, Shinichiro; Nishio, Kazuhisa; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Ishibashi, Masayuki; Kuboshima, Koji; Takeuchi, Ryuji; Mizuno, Takashi; Sato, Toshinori; et al.
JAEA-Review 2012-028, 31 Pages, 2012/08
JAEA-Review-2012-028.pdf:3.86MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is pursuing a geoscientific research and development project namely the Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to construct scientific and technological basis for geological disposal of High-level Radioactive Waste (HLW). The MIU project is planned in three overlapping phases; Surface-based Investigation Phase (Phase I), Construction Phase (Phase II) and Operation Phase (Phase III). Currently, the project is under the Construction Phase and the Operation Phase. This document introduces the research and development activities planned for 2012 fiscal year based on the MIU Master Plan updated in 2010, construction plan and research collaboration plan, etc.
Kunimaru, Takanori; Morikawa, Keita; Tachi, Yukio; Kuno, Yoshio*; Hosoya, Shinichi*; Shimoda, Satoko*; Kato, Hiroyasu*; Nakazawa, Toshiyuki*; Ikuse, Hiroyuki*; Kubota, Masako*
JAEA-Data/Code 2012-013, 96 Pages, 2012/07
JAEA-Data-Code-2012-013.pdf:7.41MBJAEA-Data-Code-2012-013(errata).pdf:0.13MB
For the purpose to understand the relationship between characteristic of mass transport and characteristic of fracture, the following experiments were carried out using core sample, which was sampled from the -300 m Stage. This paper compiled the results of these experiment. (1) Diffusion experiments of Cs, Sr, I and uranin in granite samples (2) Sorption experiments of Cs and Sr on crushed granite (3) Measurement of pore physicality by Mercury Intrusion and water saturation
Kunimaru, Takanori; Mikake, Shinichiro; Nishio, Kazuhisa; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Ishibashi, Masayuki; Ueno, Takashi; Tokuyasu, Shingo; Daimaru, Shuji; Takeuchi, Ryuji; et al.
JAEA-Review 2012-020, 178 Pages, 2012/06
JAEA-Review-2012-020.pdf:33.16MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is pursuing a geoscientific research and development project namely the Mizunami Underground Research Laboratory (MIU) Project in crystalline rock environment in order to construct scientific and technological basis for geological disposal of High-level Radioactive Waste (HLW). The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). The MIU Project has been ongoing the Phase II. And Phase III started in 2010 fiscal year. This report shows the results of the investigation, construction and collaboration studies in fiscal year 2010, as a part of the Phase II based on the MIU Master Plan updated in 2002.
Iwatsuki, Teruki; Mizuno, Takashi; Amano, Yuki; Kunimaru, Takanori; Semba, Takeshi
JAEA-Research 2011-049, 68 Pages, 2012/03
JAEA-Research-2011-049.pdf:7.24MB
This report summarizes technical basis and the Know-how on hydrochemical investigations for deep underground as a part of METI project "Development of Information Synthesis and Interpretation System (ISIS)". We describe the procedures and methods of hydrochemical investigation in following stages; (1) initial analysis of previous information, (2) planning of borehole investigation, (3) borehole investigation at field, and (4) construct the "hydrochemical model" representing hydrochemical condition and the evolution process. The contents of this report are inputted to "Expert system" developed by METI project and are available via WEB system (internet).
Nanjo, Isao; Amano, Yuki; Iwatsuki, Teruki; Kunimaru, Takanori; Murakami, Hiroaki; Hosoya, Shinichi*; Morikawa, Keita
JAEA-Research 2011-048, 162 Pages, 2012/03
JAEA-Research-2011-048.pdf:8.53MBJAEA-Research-2011-048-appendix(CD-ROM)-1.pdf:0.74MBJAEA-Research-2011-048-appendix(CD-ROM)-2.pdf:7.55MBJAEA-Research-2011-048-appendix(CD-ROM)-3.pdf:18.71MBJAEA-Research-2011-048-appendix(CD-ROM)-4.pdf:0.11MBJAEA-Research-2011-048-appendix(CD-ROM)-5.pdf:0.07MBJAEA-Research-2011-048-appendix(CD-ROM)-6.pdf:0.68MB
The observation technique of hydrochemical condition in low permeable sedimentary rock around the facility is one of R&D subjects. We report, (1) development of hydrochemical monitoring system to observe water pressure, pH, electric conductivity, dissolved oxygen, redox potential and temperature, (2) hydrochemical observation results around URL under construction. The applicability of the hydrochemical monitoring system is evaluated for low permeable sedimentary rock bearing abundant dissolved gases. The hydrochemical observation during facility construction demonstrates that pH and redox potential of groundwater almost did not changed even at hydraulic disturbed zone (water pressure decreased zone).
Amano, Yuki; Yamamoto, Yoichi; Nanjo, Isao; Murakami, Hiroaki; Yokota, Hideharu; Yamazaki, Masanori; Kunimaru, Takanori; Oyama, Takahiro*; Iwatsuki, Teruki
JAEA-Data/Code 2011-023, 312 Pages, 2012/02
JAEA-Data-Code-2011-023.pdf:5.46MBJAEA-Data-Code-2011-023(errata).pdf:0.08MB
In the Horonobe Underground Research Laboratory (URL) Project, ground water from boreholes, river water and precipitation have been analyzed for the environmental monitoring since the fiscal year 2001. This report shows the data set of water chemistry since the fiscal year 2001 to the fiscal year 2010.
Yabuuchi, Satoshi; Kunimaru, Takanori; Kishi, Atsuyasu*; Komatsu, Mitsuru*
Doboku Gakkai Rombunshu, C (Chiken Kogaku) (Internet), 67(4), p.464 - 473, 2011/11
Japan Atomic Energy Agency has been conducting the Horonobe Underground Research Laboratory (URL) project in Horonobe, Hokkaido, as a part of the research and development program on geological disposal of high-level radioactive waste. Pore water pressure and water content around a horizontal drift in the URL have been monitored for over 18 months since before the drift excavation was started. During the drift excavation, both pore water pressure and water content were decreasing. Pore water pressure has been still positive though it continued to decrease with its gradient gradually smaller after excavation, while water content turned to increase about 6 months after the completion of the excavation. It turned to fall again about 5 months later. An unsaturated zone may have been in homogeneously formed around the horizontal drift considering a degassing.
Yuguchi, Takashi; Tsuruta, Tadahiko; Mizuno, Takashi; Kunimaru, Takanori
JAEA-Data/Code 2011-009, 85 Pages, 2011/09
JAEA-Data-Code-2011-009.pdf:8.93MB
Tono Geoscientific Research Unit of Japan Atomic Energy Agency (JAEA) is carrying out the Underground Research Laboratory Project, which is a scientific study revealing the deep geological environment as a basis of research and development for geological disposal of high level radioactive wastes. The aim of the project is to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in fractured crystalline rock, and to develop a range of engineering techniques for deep underground application. This project has three overlapping phases: Surface-based investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III), with a total duration of about 20 years. Nowadays, the project is under the Phase II. Phase I and II conducted the following kinds of analyses for rock samples, which was collected from the Mizunami Underground Research Laboratory construction site. (1) Bulk chemical composition analyses (major and minor elements), (2) X-ray diffraction analyses, and (3) Mineral composition analyses. Petrological and mineralogical data is a basic information for the planning of mass transfer study in Phase III investigation. Thus, this paper compiled the results of these analyses. Thus, this paper compiled the results of these analyses.
Kunimaru, Takanori; Takeuchi, Ryuji; Matsuzaki, Tatsuji
Proceedings of 14th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2011) (CD-ROM), p.1185 - 1194, 2011/09
This study will be demonstrated the selection process for the URL area and URL site in sequence. Horonobe URL has been declared to be constructed within whole Horonobe Town to be selected early in the fiscal year 2002. The Horonobe URL area/site is required existence of host argillaceous sedimentary formations and saline groundwater. Further fundamental requirements are rock mechanical property and underground flammable (e.g. methane) gas content which meet with safe construction and operation of underground facility. Next, based on surveys of existing information and aerial and ground reconnaissance surveys on a regional scale, and taking into consideration preliminary requirements on the geological environment and safety, as well as social and environmental constraints, an area of 3 km 
3 km in the north-central part of Horonobe Town was selected as the main area for the surface-based investigations (URL area). A site for constructing the underground and surface facilities (URL site) was subsequently selected in the URL area, 3 km from the center of Horonobe Town. The selection was based on social conditions and the availability of infrastructure, including roads and land use restrictions, in addition to available geological and hydrogeological information. This study is only fruit of selecting the URL site based on the social and technical requirements in Japan. These stepwise approaches and experiences for selecting the site are applicable when the implementer (e.g. Nuclear Waste Management Organization of Japan) will select the site such as the phase of literature survey, preliminary investigation and detailed investigation in the future.
Kunimaru, Takanori; Mikake, Shinichiro; Nishio, Kazuhisa; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Takeuchi, Ryuji; Saegusa, Hiromitsu; Mizuno, Takashi; Sato, Toshinori; Ogata, Nobuhisa; et al.
JAEA-Review 2011-027, 30 Pages, 2011/08
JAEA-Review-2011-027.pdf:4.18MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is pursuing a geoscientific research and development project namely the Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to construct scientific and technological basis for geological disposal of High-level Radioactive Waste (HLW). Geoscientific research and the MIU project is planned in three overlapping phases; Surface-based Investigation Phase (Phase1), Construction Phase (Phase2) and Operation Phase (Phase3). Currently, the project is under the Construction Phase, and the Operation Phase. This document introduces the research and development activities planned for 2011 fiscal year plan based on the MIU Master Plan updated in 2010, Investigation Plan, Construction Plan and Research Collaboration Plan, etc.
Saegusa, Hiromitsu; Matsui, Hiroya; Hama, Katsuhiro; Sato, Toshinori; Tsuruta, Tadahiko; Takeuchi, Ryuji; Kunimaru, Takanori; Matsuoka, Toshiyuki; Mizuno, Takashi
JAEA-Review 2011-022, 78 Pages, 2011/06
JAEA-Review-2011-022.pdf:10.05MBJAEA-Review-2011-022(errata).pdf:0.5MB
Japan Atomic Energy Agency (JAEA) is being performed Mizunami Underground Research Laboratory (MIU) Project, which is a broad scientific study of the deep geological environment as a basis of research and development for geological disposal of nuclear wastes, in order to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in fractured crystalline rock. The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III), with a total duration of about 20 years. The project goals of the MIU Project from Phase I through to Phase III are: (1) to establish techniques for investigation, analysis and assessment of the deep geological environment, and (2) to develop a range of engineering for deep underground application. This document presents the concept and procedure of geoscientific study on Phase II and III to 500m depth.
Kunimaru, Takanori; Ota, Kunio; Alexander, W. R.*; Yamamoto, Hajime*
JAEA-Research 2011-010, 52 Pages, 2011/06
JAEA-Research-2011-010.pdf:2.29MB
Work has been currently ongoing to establish an appropriate quality management system (QMS), which is applicable to all aspects of the site characterisation process, in the Horonobe Underground Research Laboratory project. A quality assurance (QA) audit of hydrochemical datasets for JAEA's deep boreholes HDB-1 to HDB-8 was carried out, along similar lines to that of the previous study for boreholes HDB-9 to HDB-11, by applying both the groundwater QA methodology employed in the recent site assessments in Sweden and a porewater QA regime proposed in this study. The results of the QA audit indicated that data were classified into low QA categories because mainly of a lack of relevant information, such as the records of groundwater sampling, which are necessary for more fully assessing the data quality. As such, a formalised field manual for hydrochemical sampling was developed. In addition, work to further improve the site characterisation QMS progressed.
