Study on geology on the Mizunami Underground Research Laboratory Project; Geology and geological structure at the -500m stage

Kawamoto, Koji; Kuboshima, Koji*; Murakami, Hiroaki; Ishibashi, Masayuki; Sasao, Eiji

JAEA-Research 2014-021, 30 Pages, 2014/11

JAEA-Research-2014-021.pdf:6.79MB

The MIU (Mizunami Underground Research Laboratory) Project has three overlapping phases, Surface-based investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). Currently, the project is under Phase II and Phase III. One of Phase II goals is set up to develop and revise models of the geological environment using the investigation results obtained during excavation, and to determine and assess changes in the geological environment in response to excavation. This report aims at compiling results of study on geology and geological structure at the -500m Stage in the MIU construction site, investigated in the Phase II and provides the fundamental information on the geology and geological structure for future study and modeling of geological environment.

Mizunami Underground Research Laboratory Project, Annual report for fiscal year 2012

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

JAEA-Review-2013-050.pdf:19.95MB

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.

Mizunami Underground Research Laboratory Project, Annual report for fiscal year 2011

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.

Ab initio path integral molecular dynamics simulations of FH and FH

Suzuki, Kimichi*; Ishibashi, Hiroaki*; Yagi, Kiyoshi*; Shiga, Motoyuki; Tachikawa, Masanori*

Progress in Theoretical Chemistry and Physics, 26, p.207 - 216, 2012/08

https://doi.org/10.1007/978-94-007-5297-9_10

The quantum nature of the strong hydrogen bonds for the FH and FH ions and their deuterated isotopomers at the room temperature has been studied using ab initio path integral molecular dynamics (PIMD) simulations. It is found that, for both of these ions, the hydrogen-bonded H/D atoms largely fluctuate around the central position of two F atoms. The average FH/FF distances of FH and FH are longer than the average FD/FF distances of FD and FH due to the primary/secondary isotope effects, which stem from the difference of the quantum nature of H and D nuclei. These results are compared with the family of Zundel-type ions, OH, NH, OH, and NH, which have been studied previously with the same ab initio PIMD approach. A comparison is also made with the previous experimental and ab initio vibrational configuration interaction results of FH.

Geometric isotope effect on the NH cation and NH anion by path integral molecular dynamics simulation

Ishibashi, Hiroaki*; Hayashi, Aiko*; Shiga, Motoyuki; Tachikawa, Masanori*

ChemPhysChem, 9(3), p.383 - 387, 2008/02

https://doi.org/10.1002/cphc.200700570

no abstracts in English

Measures of closing report of outside waste storage pits

; Ishibashi, Yuzo; Yoshida, Michihiro; Miyo, Hiroaki; Sukegawa, Yasuhiro*; *; Suzuki, Satoshi*

JNC TN8440 2000-020, 500 Pages, 2000/10

JNC-TN8440-2000-020.pdf:25.91MB

At outside waste storage pits, containers for storage of wastes corroded and were flooded, and it was confirmed on August 26, 1997. Confirmation of contamination of the pits outskirts, installation of sheets to prevent rainwater from flowing into the pits, drawing stay water were executed, promptly. Design and authorization works of the work house and waste treatment devices to take out wastes of the pits were executed too. After construction of the work house, taking out wastes of the pits started, and finished on April 10, 1998. Investigations of the inflow point of rainwater and leak of stay water were executed next. The results were reported to Science and Thechnology Agency (STA), adjoining authorities on December 21, 1998. After decontamination of the pits inner walls to background level of the radioactivity which included general concrete, control area was removed, and the pits were closed by concrete. Measures of closing of the pits were prepared from the middle of August, 1999, and dismantlement of unnecessary instruments started. Decontamination of the pits started from the begining of September, 1999. The above works finished on June 30, 2000. After decontamination of the pits, STA, adjoining authorities confirmed the circumstances. Work pouring concrete into the pits was executed three times (three levels), and finished on August 31, 2000. In addition t0 above, the amount of concrete poured into the pits was about 1,200 m.

Denitrification in groundwater at 140 m depth in sedimentary horizon

Katsuyama, Chie*; Nashimoto, Hiroaki*; Ishibashi, Tomotaka*; Furuta, Kazuki*; Nagaosa, Kazuyo*; Yoshikawa, Hideki; Asano, Takahiro; Sasaki, Yoshito; Aoki, Kazuhiro; Suwa, Yuichi*; et al.

no journal, , 

no abstracts in English

Study on influence of fault activity to geological environment; Case study at the Mizunami Underground Research Laboratory

Sasao, Eiji; Ishibashi, Masayuki; Kuboshima, Koji*; Murakami, Hiroaki

no journal, , 

Understanding of a range influenced by fault activity is quite important, because fault activity could lead to form and/or grow crushed zone and to increase water conductivity. We described fracture frequency, fracture filling and alteration along fracture, and then discuss relationship between those features and fault at the Mizunami Underground Research Laboratory. As a result of the study, those features are dominant around faults in the Laboratory. Alteration along fracture and some of the fracture filling suggest inflow of hydrothermal fluid. This implies opening of fracture or reopening of existed fracture. We try to find the evidence of shear fracture in the future study, because fault activity would form shear fracture.

Hydrological and geological characterization of deep subsurface structures in and around the main shaft fault at the Mizunami Underground Research Laboratory

Nohara, Tsuyoshi; Sakai, Toshihiro; Murakami, Hiroaki; Ishibashi, Masayuki

no journal, , 

Existing data was analyzed in order to understand Hydrological and Geological Characterization of deep subsurface structures in and around the Main Shaft fault at the Mizunami Underground Research Laboratory. As a result, in response to the low permeability structure of the Main Shaft Fault, fault gouges and alteration parts are found to be continuously distributed in the wall of the Main Shaft. One of the most high-permeable structure was estimated to be constituted by low-angle fractures with a sheet-like calcite. Shear of low angle fractures showed relatively low permeability. It may be possible to understand the permeability structure of these features in a drilling survey of granitic rocks.

Study on distribution of micropore in granitic rock in Japan

Ishibashi, Masayuki; Sasao, Eiji; Yuguchi, Takashi*; Morikawa, Keita*; Murakami, Hiroaki

no journal, , 

Understanding of matrix diffusion is important for geological disposal of high-level radioactive waste in terms of retardation of mass transport in deep underground. Micropore is known to act as pathway of matrix diffusion. The authors found that micropore in plagioclase is important for matrix diffusion by the study of the Toki Granite, central Japan. Micropore in plagioclase is ubiquitous in the Toki Granite, while there is not much information in the other granitic rock in Japan. We investigated distribution of micropore in granitic rocks. Though only four samples were investigated at the moment, micropore in plagioclase was ubiquitously observed. Distribution of miecrocrack is heterogeneous in the different rock bodies and between two thin sections of one rock sample. We continue the observation of thin sections to confirm the distribution of micropore, and will perform through-diffusion experiment to understand relationship between micropore and matrix diffusion.