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Ogata, Misa*; Okawa, Hirotada*; Fujisawa, Kotaro*; Yasutake, Nobutoshi; Yamamoto, Yu*; Yamada, Shoichi*
Monthly Notices of the Royal Astronomical Society, 521(2), p.2561 - 2576, 2023/05
Times Cited Count：1 Percentile：21.38(Astronomy & Astrophysics)Okawa, Hirotada*; Fujisawa, Kotaro*; Yasutake, Nobutoshi; Ogata, Misa*; Yamamoto, Yu*; Yamada, Shoichi*
Monthly Notices of the Royal Astronomical Society, 520(1), p.24 - 43, 2023/03
Times Cited Count：1 Percentile：21.38(Astronomy & Astrophysics)Sasao, Eiji; Suzuki, Keiichi*; Yamada, Nobuto*; Kuboshima, Koji*
Proceedings of 12th SEGJ International Symposium (USB Flash Drive), 4 Pages, 2015/11
We performed investigation of a fault with thick and clay-altered damaged zone in granitic rock using cosmic ray muons at the Mizunami Underground Research Laboratory. Geology of the Laboratory consists of sedimentary rock and underlying granite with unconformable contact at the 170 meters below ground level (G.L.). A vertical fault with a thick, clay-altered damaged zone is present in the granite. The muon telescopes were settled at the G.L.-200 and -300 meters to estimate densities of granite and fault. Densities of granite, fault and sedimentary rock are calculated as 3.38, 2.88 and 1.99 g/cm
, respectively. The obtained density is obviously higher than absolute value, though the reason of such difference is not clear at the moment. If the density of granite is assumed to be 2.6 g/cm, then the densities of fault and sedimentary rock are re-calculated as 2.2 and 1.5 g/cm. This result indicates that cosmic ray muons have good potential to detect geological structure.
13MI44 Boreholes)Hasegawa, Takashi; Kawamoto, Koji; Yamada, Nobuto; Onuki, Kenji; Omori, Kazuaki; Takeuchi, Ryuji; Iwatsuki, Teruki; Sato, Toshinori
JAEA-Technology 2015-011, 135 Pages, 2015/07
JAEA-Technology-2015-011.pdf:28.63MB
JAEA-Technology-2015-011-appendix(CD-ROM).zip:566.32MB
The geological, hydraulic and geochemical data such as rock mass classification, groundwater inflow points and the volume, water pressure, and hydraulic conductivity were obtained from boreholes (13MI3813MI44) in the -500m Access/Research Gallery-North of Mizunami Underground Research laboratory (MIU). In addition to data acquisition, monitoring systems were installed to observe hydrochemical changes in the groundwater, and rock strain during and after the groundwater recovery experiment.
14MI51 Boreholes)Kuroiwa, Hiroshi*; Kawamoto, Koji; Yamada, Nobuto; Sasao, Eiji
JAEA-Data/Code 2015-003, 108 Pages, 2015/06
JAEA-Data-Code-2015-003.pdf:10.4MBJAEA-Data-Code-2015-003(errata).pdf:1.51MBJAEA-Data-Code-2015-003-appendix(CD-ROM).zip:1150.87MB
Japan Atomic Energy Agency (JAEA) is performing the Mizunami Underground Research Laboratory (MIU) Project, which is a scientific study of the deep geological environment as a basis of research and development for geological disposal of high level radioactive wastes (HLW), in order to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in the crystalline rock. The MIU Project has three overlapping phases, Surface-based investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). This report compiles the data of results from borehole investigations which has been carried out in the research gallery in the fiscal year from 2012 to 2014. These data include results of core observation, geophysical logging, and so on.
Hama, Katsuhiro; Mikake, Shinichiro; Nishio, Kazuhisa; Kawamoto, Koji; Yamada, Nobuto; Ishibashi, Masayuki; Murakami, Hiroaki; Matsuoka, Toshiyuki; Sasao, Eiji; Sanada, Hiroyuki; et al.
JAEA-Review 2014-038, 137 Pages, 2014/12
JAEA-Review-2014-038.pdf:162.61MB
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 2013. This report presents the results of the investigations, construction and collaboration studies in fiscal year 2013, as a part of the Phase II and Phase III based on the MIU Master Plan updated in 2010.
Kawamoto, Koji; Kuroiwa, Hiroshi; Yamada, Nobuto; Onuki, Kenji; Omori, Kazuaki; Takeuchi, Ryuji; Ogata, Nobuhisa; Omori, Masaki; Watanabe, Kazuhiko
JAEA-Technology 2014-011, 92 Pages, 2014/07
JAEA-Technology-2014-011.pdf:24.65MBJAEA-Technology-2014-011-appendix(DVD).zip:331.54MB
This document summarizes the data of pilot boreholes (12MI32) in the -500m Access/Research Gallery-South. The geological, hydraulic and geochemical data were obtained. In addition, groundwater monitoring system was installed to observe the groundwater pressure in initial condition and change during the excavation of gallery. The results of investigation, biotite granite with medium to coarse-grained equigranular texture are characterized. Rock mass classification is B from CM class. Minor fault with fault breccia are observed around 48.90mabh. However, S200_13 fault and IF_SB3_13_3 fault (that were presumed by an original model) were not observed. Density of fracture is large in the section of 40.00 to 80.00mabh. Water inflow was a maximum of 600 L/min in 78.83mabh. Permeability ranges from 2.0E-9 to 1.5E-08m/sec at the zone with low inflow, from 1.1E-05 to 1.6E-05m/sec at the zone with high inflow, respectively. Groundwater chemistry is rich in Na and Cl ion.
Hasegawa, Ken; Yamada, Nobuto; Koide, Kaoru
JAEA-Research 2014-004, 177 Pages, 2014/06
JAEA-Research-2014-004.pdf:36.19MB
Tono Geoscience Center conducted CSMT and MT surveys in the region of the Toki granite from 1997 to 1999, as a part of the Regional Hydrogeological Study. After these surveys were performed, applicability of MT method to prospecting of the deeper part of the granite was evaluated. As a result, several problems of CSMT and MT surveys were pointed out. Accordingly, we checked the quality of data obtained through the surveys and found out that the interpretation results of the underground resistivity distribution are deficient in reliability because almost all data contain large artificial electromagnetic noise. Major reason behind its poor results is adoption of the high-frequency tensor CSMT system. Because of its ease of data acquisition, it was adopted without investigation of electromagnetic noises around the survey area. This fact indicated that we must investigate details of the noise around survey area in advance and select optimum equipment and survey specifications, which can distinguish a signal from data containing such large noise.
Tsuyuguchi, Koji; Kuroiwa, Hiroshi; Kawamoto, Koji; Yamada, Nobuto; Onuki, Kenji; Iwatsuki, Teruki; Takeuchi, Ryuji; Ogata, Nobuhisa; Suto, Masahiro; Mikake, Shinichiro
JAEA-Technology 2013-044, 89 Pages, 2014/02
JAEA-Technology-2013-044.pdf:11.09MBJAEA-Technology-2013-044-appendix(CD-ROM).zip:316.8MB
This document summarizes the data of pilot boreholes (12MI27, 12MI33) in the -500m Access/Research Gallery-North. The geological, hydraulic and geochemical data were obtained. In addition, groundwater monitoring system was installed in closure test gallery for the flooding test in phase III research. The results of investigation, biotite granite with medium to coarse-grained equigranular texture are characterized. Rock mass classification is B from CH class. Minor fault with fault gouge that was not presumed by an original model are observed in 12MI33. Density of fracture in 12MI27 near the Main-shaft fault tends to be compared to 12MI33. Water inflow in both boreholes is less. Permeability ranges from 4.8E-10 to 6.1E-09m/sec at the zone without alteration and with low inflow, from 1.1E-07 to 2.7E-07m/sec at the zone without alteration and with high inflow, respectively. Groundwater chemistry is rich in Na and Cl ion.
Hasegawa, Ken; Yamada, Nobuto; Endo, Yoshinobu*; Koide, Kaoru
JAEA-Research 2013-028, 83 Pages, 2013/12
JAEA-Research-2013-028.pdf:18.29MB
To evaluate the applicability of the airborne geophysical methods to granitic area, Tono Geoscience Center conducted the airborne geophysical survey using helicopter in the region of the Toki granite from 1997 to 1999. Data of electromagnetic survey, magnetic survey and radiometric survey were collected. This time, we re-interpreted these data. The following is the summary of the results obtained. (1) Electromagnetic survey; We developed the new calculation method and the data was reprocessed. As a result, it made us possible to obtain the apparent resistivity value corresponding to the rock resistivity. And the new apparent resistivity contour map clearly shows the depth changes of the granitic rock. (2) Magnetic survey; Magnetic susceptibility of the target granite is not uniform. From the viewpoint of magnetic susceptibility, the granite is divided into about five parts using a color shaded relief map. This map is a very useful tool for a qualitative interpretation of magnetic data. (3) Radiometric Survey; Some local anomalies were obtained. It is inferred that they correspond with the autocrops of the granitic rocks or the uranium deposits, not with the open fractures. These results indicate that an airborne geophysical survey using helicopter provides the useful information for planning of the geological and geophysical ground surveys.
Matsuoka, Toshiyuki; Hodotsuka, Yasuyuki*; Yamada, Nobuto
JAEA-Research 2012-028, 70 Pages, 2012/11
JAEA-Research-2012-028.pdf:19.33MB
Reverse Vertical Seismic Profiling (R-VSP) using vibration during the construction of underground facility has been carried out at the MIU construction site to develop the technique that estimate the 3-dimensional geological structure. In this report, we apply plural data processing/analysis methods (VSP-CDP transform, VSP migration, IP transform and seismic interferometory) to observed vibration data (blasting data, drilling vibration data and construction noise data), and discuses the applicability of the R-VSP. In this study, geological structures such as unconformities between sedimentary rocks and granite, and steep faults were extracted using applied prual data processing/analysis methods. We conclude that it is likely that the R-VSP using various vibration data and prual data processing/analysis, can apply to estimate the 3-dimensional geological structure.
Kawaguchi, Masanao; Nakanishi, Tatsuro; Kishi, Hirokazu; Nobuto, Jun*; Yamada, Tsutomu*; Fujita, Tomoo; Hatanaka, Koichiro
JAEA-Data/Code 2012-007, 250 Pages, 2012/11
JAEA-Data-Code-2012-007.pdf:20.55MB
Cementitious materials are commonly used for rock support, lining, and grouting, their pH plume are considered to have an adverse effect on long-term safety of a geological disposal system. In addition, during the emplacement of waste package with buffer material, it is required to limit amount of groundwater inflow to a certain level by grouting. Therefore, it is necessary to develop new grout materials with penetrability for smaller fractures. We have developed new grout materials, which have better penetrability and are environmentally more friendly than exinting cementitious grout materials since FY 2007. This sequel report shows the most appropriate composition and the penetration characteristic of new grout materials to be suitable for the 
experiment based on the result of indoor test carried out after FY 2008.
Fukuoka, Naomi; Shinkai, Fumiaki; Miura, Norihiko*; Nobuto, Jun*; Yamada, Tsutomu*; Naito, Morimasa
JAEA-Data/Code 2010-005, 353 Pages, 2010/07
JAEA-Data-Code-2010-005-01.pdf:8.91MBJAEA-Data-Code-2010-005-02.pdf:46.47MB
High-level radioactive waste management in Japan is based on the multi-barrier concept, composed of the engineered barrier system and the surrounding geological formations. Although cementitious materials are commonly used for rock support, lining, and grouting, their pH plume are considered to have an adverse effect on long-term safety of a geological disposal system. In addition, during the emplacement of waste package with buffer material, it is required to limit amount of groundwater inflow into a disposal pit or tunnel to a certain level by grouting because the bentonite clay buffer is easy to swell in time by contact with the groundwater. Therefore, it is necessary to develop new grout materials with penetrability for smaller fractures. This report shows the most appropriate composition of new grout materials to be suitable for the in-situ experiment based on the result of indoor test.
Hodotsuka, Yasuyuki; Matsuoka, Toshiyuki; Tsuruta, Tadahiko; Yamada, Nobuto*; Ishigaki, Koichi*; Yamaguchi, Shinji*
Shadan Hojin Butsuri Tansa Gakkai Dai-119-Kai (Heisei-20-Nendo Shuki) Gakujutsu Koenkai Koen Rombunshu, p.61 - 64, 2008/10
Seismic interferometry using the vibration under the construction works such as borehole drilling, mucking, blasting etc., had been carried out to develop the method that obtain three-dimensional geological image, around the Mizunami Underground Research Laboratory. In this study, we discussed the applicability of this method analytical accuracy depending on vibration resource types.
Matsuoka, Toshiyuki; Hodotsuka, Yasuyuki; Tsuruta, Tadahiko; Ishigaki, Koichi*; Yamada, Nobuto*; Yamaguchi, Shinji*
Shadan Hojin Butsuri Tansa Gakkai Dai-119-Kai (Heisei-20-Nendo Shuki) Gakujutsu Koenkai Koen Rombunshu, p.65 - 67, 2008/10
A reverse VSP (R-VSP) using the blasting vibration been carried out to obtain three-dimensional geological image around the Mizunami Underground Research Laboratory under the shaft excavation works. In this study, the applicability of this method was discussed.
Yamada, Nobuto*; Ishigaki, Koichi*; Yamaguchi, Shinji*; Narita, Norifumi*; Matsuoka, Toshiyuki; Hodotsuka, Yasuyuki; Matsuoka, Toshifumi*
Shadan Hojin Butsuri Tansa Gakkai Dai-117-Kai (Heisei-19-Nendo Shuki) Gakujutsu Koenkai Koen Rombunshu, p.146 - 148, 2007/10
Seismic interferometry synthesizes the Green's function between two receivers by calculating cross-correlation of records measured at their locations. In Japan Atomic Energy Agency(JAEA), Seismic Interferometry using blasting vibration caused by the shafts excavation had been carried out to investigate the geologic structure in the surrounding area. The result was identical to the existing seismic reflection section. In this study, we applied this technique to long time measured microtremor. The result was also identical to the results of existing section and seismic interferometry using blasting vibration caused by the shafts excavation.
Ishibashi, Masayuki; Kawamoto, Koji; Sasao, Eiji; Murakami, Hiroaki; Yamada, Nobuto
no journal, ,
no abstracts in English
Yamada, Nobuto; Suzuki, Keiichi*; Kanazawa, Sunao*; Tsuge, Takashi*
no journal, ,
To evaluate the distribution of geological discontinuity such as fractures around the underground gallery is one of the important factors to conduct high level radioactive waste disposal, but it is difficult to evaluate them enough only by geological survey such as boring investigations. We carried out GPR to obtain the distribution of fractures exist nearby the underground gallery of granite in Mizunami Underground Research Laboratory, and understand that we can detect them by GPR.
Yamada, Nobuto; Sasao, Eiji; Kuboshima, Koji*; Suzuki, Keiichi*
no journal, ,
JAEA and KGE perform the joint research on cosmic ray muons applying detection of sub-surface geological structure such as fault, using the research gallery of the Mizunami Underground Research Laboratry. We set the detectors of cosmic ray muons in the underground gallery to assess its applicability for estimating geological structure in deep underground. We estimate the geological structure by the number of cosmic ray muons observed from November 2013 to August 2014 and confirm that we can observe the substantial number of cosmic ray muons to estimate the geological structure in the research gallery of granite at G.L.-300m.
Sasao, Eiji; Yamada, Nobuto; Kuroiwa, Hiroshi; Kuboshima, Koji; Kawamoto, Koji; Ishibashi, Masayuki; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Murakami, Hiroaki
no journal, ,
no abstracts in English
