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Hama, Katsuhiro; Iwasaki, Riyo*; Morikawa, Keita*
JAEA-Technology 2017-015, 45 Pages, 2017/07
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
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.
Yamashita, Riyo; Hama, Katsuhiro; Takeuchi, Ryuji; Morikawa, Keita*; Hosoya, Shinichi*; Nakamura, Toshiaki*; Tanaka, Yumiko*
JAEA-Technology 2014-029, 118 Pages, 2014/09
This study is to gain a better understanding of mass transfer phenomena in the geological environment as well as to develop technologies for: measurement of the solute transport parameters, model construction, numerical analysis and validation of all those technologies based on the existing information. As part of solute transport study, laboratory experiments were planned to understand the influence of the geological characteristics of fracture on the solute transport parameters, also understand the differences in test results by the different sizes of the samples used for an experiment, and moreover to validate the parameters obtained by numerical analysis.
Hama, Katsuhiro; Mikake, Shinichiro; Nishio, Kazuhisa; Matsuoka, Toshiyuki; Ishibashi, Masayuki; Sasao, Eiji; Hikima, Ryoichi*; Tanno, Takeo*; Sanada, Hiroyuki; Onoe, Hironori; et al.
JAEA-Review 2013-050, 114 Pages, 2014/02
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 fiscal year 2012. This report presents the results of the investigations, construction and collaboration studies in fiscal year 2012, as a part of the Phase II and Phase III based on the MIU Master Plan updated in 2010.
Yuguchi, Takashi; Ishibashi, Masayuki; Morikawa, Keita; Kunimaru, Takanori
JAEA-Data/Code 2013-004, 38 Pages, 2013/06
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.
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
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
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.
Nanjo, Isao; Amano, Yuki; Iwatsuki, Teruki; Kunimaru, Takanori; Murakami, Hiroaki; Hosoya, Shinichi*; Morikawa, Keita
JAEA-Research 2011-048, 162 Pages, 2012/03
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).
Iwatsuki, Teruki; Morikawa, Keita*; Hosoya, Shinichi*; Yoshikawa, Hideki
Chikasui Gakkai-Shi, 51(3), p.205 - 214, 2009/08
Physicochemical parameters of deep groundwater at the depth of 500 m were measured at ground surface and the in-situ sampling depth of borehole to understand the redox condition and dominant redox process. The results show that the redox potential at the depth was approximately -100 mV and was controlled by the reaction of chemical pairs of (Fe, SO)/(FeS) or (SO, FeCO)/(FeS). The pH value at ground surface changed approximately 0.4 from that at the in-situ depth by degassing of dissolved carbon dioxide. The time to reach the stable ORP value in monitoring depends on the shape and surface area of Pt electrode. The columnar-shape Pt electrode is more sensitive for deep groundwater rather than a dot-shape Pt electrode. It is important to correct the pH measured at ground surface for the analysis of in-situ redox reaction process.
Morikawa, Keita*; Iwatsuki, Teruki; Hosoya, Shinichi*
no journal, ,
Measurement of redox potential in deep groundwater was conducted at ground surface and in-situ monitoring part of borehole to refine the properties of ORP electrode. The results show that the time to reach the stable value of redox potential depends on shape of Pt electrode.
Nanjo, Isao; Kunimaru, Takanori; Iwatsuki, Teruki; Hosoya, Shinichi*; Morikawa, Keita*
no journal, ,
The instrument for groundwater monitoring technique, which can continuously monitor the pore water pressure and physico-chemical parameters has developed, to monitor the hydrological and geochemical disturbances caused by underground facility construction. The pore water pressure was observed almost the same value after the circulation for the measurement of physico-chemical parameters. It was able to be confirmed that the continuous measurement for physico-chemical parameters doesn't influence the observation of pore water pressure.
Morikawa, Keita; Kunimaru, Takanori
no journal, ,
no abstracts in English
Tanaka, Yasuharu*; Goto, Kazuyuki*; Miyagawa, Kimio*; Tsukuda, Kazuhiro*; Goshima, Keiichiro*; Kunimaru, Takanori; Tsuruta, Tadahiko; Morikawa, Keita; Yuguchi, Takashi
no journal, ,
no abstracts in English
Yuguchi, Takashi; Kunimaru, Takanori; Morikawa, Keita; Uehara, Tomoko
no journal, ,
no abstracts in English
Yuguchi, Takashi; Kunimaru, Takanori; Morikawa, Keita; Uehara, Tomoko; Ishibashi, Masayuki; Yoshida, Hidekazu*; Tanaka, Yasuharu*
no journal, ,
no abstracts in English
Morikawa, Keita; Kunimaru, Takanori; Yuguchi, Takashi; Uehara, Tomoko
no journal, ,
no abstracts in English
Morikawa, Keita; Yuguchi, Takashi; Kunimaru, Takanori; Ishibashi, Masayuki; Hayano, Akira; Sawada, Atsushi
no journal, ,
no abstracts in English
Morikawa, Keita; Kunimaru, Takanori; Yuguchi, Takashi; Hosoya, Shinichi*
no journal, ,
no abstracts in English
Hosoya, Shinichi*; Seno, Shoji*; Nakajima, Makoto*; Atsumi, Hiroyuki*; Ishibashi, Masayuki; Morikawa, Keita; Onoe, Hironori; Kunimaru, Takanori
no journal, ,
Discrete Fracture Network (DFN) model provides the basis of groundwater flow analysis and solute transport analysis for crystalline rock. Due to its complexity, it is difficult to estimate how the input parameters influence the result of the analysis. In this study, using the data obtained in the Mizunami Underground Research Laboratory (MIU) project conducted by Japan Atomic Energy Agency (JAEA), we examined how the modeling methodology influenced the result of groundwater flow analysis and solute transport analysis.
Morikawa, Keita; Yuguchi, Takashi; Hama, Katsuhiro; Takeuchi, Ryuji
no journal, ,
no abstracts in English