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Takayasu, Kentaro; Onuki, Kenji*; Kawamoto, Koji*; Takayama, Yusuke; Mikake, Shinichiro; Sato, Toshinori; Onoe, Hironori; Takeuchi, Ryuji
JAEA-Technology 2017-011, 61 Pages, 2017/06
JAEA-Technology-2017-011.pdf:9.15MB
The Groundwater REcovery Experiment in Tunnel (GREET) was put into effect as development of drift backfilling technologies. This test was conducted by making the Closure Test Drift (CTD) recovered with water after carrying out a plug around 40m distance from northern edge face of horizontal tunnel of depth 500m, for the purpose of investigation of recovering process of rock mass and groundwater under the influence of excavation of tunnel. This report presents the efforts of backfilling investigation using bentonite composite soil and execution of backfilling into borehole pits excavated in the CTD which were carried out in fiscal 2014 as a part of GREET, and succeeding observation results inside pits from September 2014 to March 2016.
Hama, Katsuhiro; Mikake, Shinichiro; Ishibashi, Masayuki; Sasao, Eiji; Kuwabara, Kazumichi; Ueno, Tetsuro; Onuki, Kenji*; Beppu, Shinji; Onoe, Hironori; Takeuchi, Ryuji; et al.
JAEA-Review 2015-024, 122 Pages, 2015/11
JAEA-Review-2015-024.pdf:80.64MB
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 technical 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 III, as the Phase II was concluded for a moment with the completion of the excavation of horizontal tunnels at GL-500m level in February 2014. This report presents the results of the investigations, construction and collaboration studies in fiscal year 2014.
Toya, Naruhisa*; Ogawa, Ken*; Iwatsuki, Teruki; Onuki, Kenji
JAEA-Technology 2015-023, 35 Pages, 2015/09
JAEA-Technology-2015-023.pdf:9.44MB
One of the major subjects of the ongoing geoscientific research program is the Mizunami Underground Research Laboratory (MIU) Project in the Tono area, central Japan is accumulation of knowledge about a recovery of the geological environment during and after the facility closure. Then it's necessary to plan the observation system which can use after the backfill of research tunnels. The main purpose of this report is contribution to the detailed design for relocation of the underground monitoring systems to ground surface. We discussed the restriction and requirement for the underground monitoring systems which can use after the backfill. Furthermore, we made the conceptual design for relocation of the current underground monitoring systems to ground surface.
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.
Takayama, Yusuke; Sato, Toshinori; Onoe, Hironori; Iwatsuki, Teruki; Saegusa, Hiromitsu; Onuki, Kenji
Dai-43-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koenshu (CD-ROM), p.313 - 318, 2015/01
In the Mizunami Underground Research Laboratory, groundwater recovery experiment is being conducted to construct the method to understand the transition of geological environment due to groundwater recovery at the -500m access and research gallery-north. As a part of this experiment, backfill test is planned using drilling pits filled with artificial materials (clay and concrete) to evaluate the influence on the surrounding rock mass due to the interaction of rock and artificial materials. In this study, numerical simulation of the backfill test has been carried out to predict the qualitative hydro-mechanical behavior.
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.
Onoe, Hironori; Iwatsuki, Teruki; Saegusa, Hiromitsu; Onuki, Kenji; Takeuchi, Ryuji; Sanada, Hiroyuki; Ishibashi, Masayuki; Sato, Toshinori
Proceedings of 8th Asian Rock Mechanics Symposium (ARMS-8) (USB Flash Drive), 10 Pages, 2014/10
The selection of a geological disposal site for high-level radioactive waste (HLW) will be done taking into consideration performance of the geological environment. Geological environments would likely be influenced for several decades by changes due to the construction and operation of a large underground facility such as a HLW repository. Therefore, the post-closure recovery of the geological environment after backfilling of a facility is an important aspect for the safety assessment of geological disposal of HLW. With a focus on the hydraulic pressure and hydrochemical recovery processes around underground galleries in fractured crystalline rock, the groundwater recovery experiment will be conducted at the Mizunami Underground Research Laboratory to evaluate the natural groundwater and hydrochemical recovery of the rock mass. This paper provides an outline of the groundwater recovery experiment plan and progress of the supporting field investigations.
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.
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.
Onoe, Hironori; Daimaru, Shuji*; Onuki, Kenji; Karino, Tomoyuki; Takeuchi, Ryuji
no journal, ,
The Mizunami Underground Research Laboratory (MIU) is now under construction by the Japan Atomic Energy Agency, in the Cretaceous Toki granite in the Tono area, Central Japan. In Phase II of the MIU Project, hydrogeological investigations and long-term groundwater pressure monitoring are to be carried out in order to confirm adequacy of the groundwater flow conceptual model constructed in Phase I. In this paper, adequacy of the groundwater flow conceptual model is confirmed using groundwater flow simulation based on data from pumping test was carried out from the -300 m Access/Research Gallery.
Onuki, Kenji; Daimaru, Shuji*; Onoe, Hironori; Takeuchi, Ryuji
no journal, ,
The Mizunami Underground Research Laboratory (MIU) is now under construction by the Japan Atomic Energy Agency, in the Cretaceous Toki granite in the Tono area, Central Japan. In Phase I and Phase II of the MIU Project, distribution of low permeable fault was confirmed in the MIU construction site. And it was estimated that the fault is significant structure for groundwater flow condition around the MIU construction site. In this paper, hydrogeological characteristics of the fault are evaluated based on data from hydraulic packer test was carried out from the -300 m Access/Research Gallery.
Karino, Tomoyuki; Tsuyuguchi, Koji; Onoe, Hironori; Sato, Seiji; Onuki, Kenji; Takeuchi, Ryuji
no journal, ,
In this paper, a part of the result of long-term hydraulic pressure monitoring during the URL excavation in Phase 2 of MIU project were introduced. And, trend of long-term groundwater pressure changes of monitoring boreholes in and around the MIU construction site due to the 2011 off the Pacific coast of Tohoku Earthquake were introduced.
Iwatsuki, Teruki; Sato, Toshinori; Takeuchi, Ryuji; Onoe, Hironori; Onuki, Kenji; Saegusa, Hiromitsu; Hasegawa, Takashi; Kuroiwa, Hiroshi; Tsuyuguchi, Koji; Ikeda, Koki; et al.
no journal, ,
Closure experiment of gallery of MIU is planned to understand the recovery process of geological environments after the closure. Flooding test gallery and monitoring boreholes are designed at 500 m access gallery to observe recovery of water pressure, chemistry around cement and burial materials, rock stress. Evaluation of numerical analysis methods on hydraulic, chemical and mechanical change will be conducted based on the results of upcoming closure experiment.
Beppu, Shinji; Onoe, Hironori; Sato, Seiji; Onuki, Kenji; Takeuchi, Ryuji; Ogata, Nobuhisa
no journal, ,
no abstracts in English
Tsuyuguchi, Koji*; Takeuchi, Ryuji; Onoe, Hironori; Sato, Seiji; Onuki, Kenji; Beppu, Shinji; Ogata, Nobuhisa
no journal, ,
no abstracts in English
Onoe, Hironori; Beppu, Shinji; Onuki, Kenji; Kohashi, Akio; Takeuchi, Ryuji; Saegusa, Hiromitsu
no journal, ,
no abstracts in English
Sakaki, Toshihiro*; Sanada, Hiroyuki; Onuki, Kenji; Takeuchi, Ryuji
no journal, ,
no abstracts in English