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Nara, Yoshitaka*; Kato, Masaji*; Niri, Ryuhei*; Kono, Masanori*; Sato, Toshinori; Fukuda, Daisuke*; Sato, Tsutomu*; Takahashi, Manabu*
Pure and Applied Geophysics, 175(3), p.917 - 927, 2018/03
Times Cited Count：14 Percentile：57.88(Geochemistry & Geophysics)Information on the permeability of rock is essential for various geoengineering projects. It is especially important to investigate how fractures and pores influence the physical and transport properties of rock. Infiltration of groundwater through the damage zone fills fractures in granite with fine-grained minerals. However, the permeability of rock possessing a fracture naturally filled with fine-grained mineral grains has yet to be investigated. In this study, the permeabilities of granite samples, including a macro-fracture filled with clay and a mineral vein, are investigated. The permeability of granite with a fine-grained mineral vein agrees well with that of the intact sample, whereas the permeability of granite possessing a macro-fracture filled with clay is lower than that of the macro-fractured sample. The decrease in the permeability is due to the filling of fine-grained minerals and clay in the macro-fracture. It is concluded that the permeability of granite increases due to the existence of the fractures, but decreases upon filling them with fine-grained minerals.
Mizuno, Takashi; Aosai, Daisuke; Shingu, Shinya; Hagiwara, Hiroki; Yamamoto, Yuhei; Fukuda, Akari
Nihon Genshiryoku Gakkai Wabun Rombunshi, 12(1), p.89 - 102, 2013/03
no abstracts in English
Fukuda, Akari; Mizuno, Takashi; Aosai, Daisuke; Hagiwara, Hiroki; Yamamoto, Yuhei; Shingu, Shinya; Ito, Kazumasa*; Suzuki, Yohei*; Kozuka, Mariko*; Konno, Yuta*
no journal, ,
no abstracts in English
Mizuno, Takashi; Hagiwara, Hiroki; Aosai, Daisuke; Shingu, Shinya; Yamamoto, Yuhei; Fukuda, Akari
no journal, ,
no abstracts in English
Aosai, Daisuke; Hagiwara, Hiroki; Shingu, Shinya; Yamamoto, Yuhei; Fukuda, Akari; Suzuki, Yohei*; Mizuno, Takashi
no journal, ,
The hydrochemical investigation focused on the deep groundwater is generally conducted by using groundwater samples taken from deep boreholes. It is impossible to avoid the contamination of the groundwater from drilling fluid during borehole drilling. Although the groundwater samples taken from borehole is contaminated with drilling fluid, the ratio of the contamination can be evaluated based on the tracer (e.g. fluorescence dye) concentration that is added to the drilling fluid, quantitatively. This methodology can apply to quantitative determination of major element and isotopic composition in groundwater by extrapolating. However, it is not argued about the applicability of this methodology for the quantitative and/or qualitative determination of minor elements, microbes, organics and colloid in groundwater. This study aimed to understand the impact caused by borehole drilling to hydrochemical properties focused on the concentration of dissolved oxygen (DO). As the result, some knowledge was obtained as follows; (1) Oxygen intruded into in-situ groundwater during drilling even though borehole was artesian condition. (2) The contamination of DO during borehole drilling can be monitored by measurement of DO concentration. (3) It is recommended that DO concentration should be measured by Winkler method in addition to common electrode method for obtaining the reliable result.
Mizuno, Takashi; Aosai, Daisuke; Shingu, Shinya; Yamamoto, Yuhei; Fukuda, Akari; Hagiwara, Hiroki
no journal, ,
no abstracts in English
Aosai, Daisuke; Hagiwara, Hiroki; Shingu, Shinya; Yamamoto, Yuhei; Fukuda, Akari; Mizuno, Takashi
no journal, ,
no abstracts in English
Mizuno, Takashi; Aosai, Daisuke; Shingu, Shinya; Hagiwara, Hiroki; Yamamoto, Yuhei; Fukuda, Akari
no journal, ,
no abstracts in English
Fukuda, Akari; Mizuno, Takashi; Aosai, Daisuke; Hagiwara, Hiroki; Yamamoto, Yuhei; Shingu, Shinya; Takeno, Naoto*; Suzuki, Yohei*; Konno, Yuta*; Kozuka, Mariko*
no journal, ,
no abstracts in English
Fukuda, Yuhei; Arai, Yoichi; Suganuma, Takashi; Hinai, Hiroshi; Sano, Yuichi; Shibata, Atsuhiro; Nomura, Kazunori
no journal, ,
no abstracts in English
Fukuda, Yuhei; Suganuma, Takashi; Hinai, Hiroshi; Ikeda, Akira*; Obata, Masamichi*; Shibata, Atsuhiro; Nomura, Kazunori
no journal, ,
no abstracts in English
Fukuda, Yuhei; Suganuma, Takashi; Hinai, Hiroshi; Ikeda, Akira*; Obata, Masamichi*; Shibata, Atsuhiro; Nomura, Kazunori
no journal, ,
no abstracts in English
Fukuda, Yuhei; Hinai, Hiroshi; Shibata, Atsuhiro; Nomura, Kazunori; Ikeda, Akira*; Obata, Masamichi*; Ichikawa, Masashi*; Takahashi, Ryota*; Hirayama, Fumio*
no journal, ,
no abstracts in English
Fukuda, Yuhei; Arai, Yoichi; Hinai, Hiroshi; Nomura, Kazunori; Ikeda, Akira*; Obata, Masamichi*; Ichikawa, Masashi*; Takahashi, Ryota*; Hirayama, Fumio*
no journal, ,
no abstracts in English
Hinai, Hiroshi; Arai, Yoichi; Fukuda, Yuhei; Kurosawa, Akira; Koma, Yoshikazu; Shibata, Atsuhiro; Nomura, Kazunori
no journal, ,
Multi-Radionuclide Removal System (MRRS) has been operating to decontaminate the contaminated water in Fukushima Daiichi Nuclear Power Station. MRRS consist of pretreatment facilities (Iron coprecipitation treatment facility and Carbonate precipitation treatment facility) and adsorption towers. This system is able to remove most of the radioactive materials except Tritium. However, Associated with a this process, the secondary radioactive wastes (slurry, spent adsorbent) were generated and stored temporary in the High Integrity Container (HIC). It is necessary to various properties investigation for the inventory evaluation and future disposal. Therefore, the carbonate slurry samples were transported from Fukushima Daiichi Nuclear Power Station to our laboratories in Tokai-mura and analyzed. High concentration of Sr-90 (1.3
10
[Bq/cm
]) was determined in the sample by the radioactive measurement, it is inferred that the contaminated water has been concentrate. And small amount of 
-ray emitting nuclides were determined. As the result of ICP-AES, it is estimated that most of slurry occupy CaCO
and Mg(OH)
. These obtained data showed that decontamination system is operating normally. Also, the particle size of the slurry was analyzed by image analyzing method. The particles of slurry was found to have a median particle diameter of several 
m.
