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Yamaguchi, Tetsuji; Sakamoto, Yoshifumi; Akai, Masanobu; Takazawa, Mayumi; Iida, Yoshihisa; Tanaka, Tadao; Nakayama, Shinichi
Physics and Chemistry of the Earth, 32(1-7), p.298 - 310, 2007/00
Times Cited Count：44 Percentile：72.78(Geosciences, Multidisciplinary)Dissolution rate of montmorillonite, diffusivity of hydroxide ion and permeability coefficient in compacted sand-bentonite mixtures were experimentally determined and formulated. A coupled mass-transport/chemical-reaction code was developed to predict variation in permeability of engineered bentonite barrier with alkaline fluid by using the formulae.
Yamaguchi, Tetsuji; Sakamoto, Yoshifumi; Iida, Yoshihisa; Negishi, Kumi; Taki, Hiroshi; Akai, Masanobu; Jinno, Fumika; Kimura, Yuichiro; Ueda, Masato; Tanaka, Tadao; et al.
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10
no abstracts in English
Tanaka, Tadao; Sakamoto, Yoshifumi; Yamaguchi, Tetsuji; Takazawa, Mayumi; Akai, Masanobu; Negishi, Kumi; Iida, Yoshihisa; Nakayama, Shinichi
JAERI-Conf 2005-007, p.105 - 110, 2005/08
Highly alkaline environments induced by cementitious materials in radioactive waste repositories are likely to dissolve and to alter montmorillonite, the main constituent of bentonite buffer materials. For the prediction of the long-term variations in permeability of compacted sand-bentonite mixtures, long-term alteration of bentonite should be quantified based on information accumulated by using the compacted or powdered bentonite materials, with batch experiments or column experiments. In this study, we summarize distinctive information obtained from various experimental systems, and propose functional and effective integration of experimental approaches to prediction of bentonite alteration.
Takazawa, Mayumi; Negishi, Kumi; Sakamoto, Yoshifumi; Akai, Masanobu; Yamaguchi, Tetsuji; Iida, Yoshihisa; Tanaka, Tadao; Nakayama, Shinichi
JAERI-Conf 2005-007, p.236 - 241, 2005/08
no abstracts in English
Nakayama, Shinichi; Sakamoto, Yoshifumi; Yamaguchi, Tetsuji; Akai, Masanobu; Tanaka, Tadao; Sato, Tsutomu*; Iida, Yoshihisa
Applied Clay Science, 27(1-2), p.53 - 65, 2004/10
Times Cited Count：83 Percentile：89.21(Chemistry, Physical)Alkaline environments induced by cement in radioactive waste repositories are likely to alter montmorillonite, the main constituent of bentonite buffer materials. Over long time periods, the alteration may cause the physical and/or chemical properties of the buffer to deteriorate. For the purpose of acquiring numerical data to quantify the effect of alteration on permeability of bentonite buffer, dissolution rates of montmorillonite and diffusivity of hydroxide ions in compacted sand-bentonite mixture specimens have been measured under highly alkaline, simulated groundwater conditions. The dissolution rate of montmorillonite was given by the linear dependence on time under the employed experimental conditions of pH 13 to 14 and temperatures of 90 to 170
C. The diffusivity of hydroxide ions was obtained in through-diffusion experiments combined with a pore diffusion model. The experiments were performed under relatively low temperatures of 10 to 50C to minimize the effect of alteration of bentonite. The effective diffusivity was on the order of 10
to 10
m
/s.
Takazawa, Mayumi; Yamaguchi, Tetsuji; Sakamoto, Yoshifumi; Akai, Masanobu; Tanaka, Tadao; Nakayama, Shinichi
NUMO-TR-04-05, p.A3_59 - A3_62, 2004/10
no abstracts in English
Yamada, Fumika; Yamaguchi, Tetsuji; Maeda, Toshikatsu; Mizuno, Tsuyoshi; Sakamoto, Yoshifumi*; Negishi, Kumi*; Tanaka, Tadao; Iida, Yoshihisa
no journal, ,
no abstracts in English
Iida, Yoshihisa; Yamaguchi, Tetsuji; Yamada, Fumika; Maeda, Toshikatsu; Sakamoto, Yoshifumi*; Mizuno, Tsuyoshi; Tanaka, Tadao; Nakayama, Shinichi
no journal, ,
no abstracts in English
Tanaka, Tadao; Yamaguchi, Tetsuji; Iida, Yoshihisa; Kimura, Yuichiro; Taki, Hiroshi; Fujiwara, Takeshi; Ueda, Masato*; Mukai, Masayuki; Yamada, Fumika; Mizuno, Tsuyoshi; et al.
no journal, ,
no abstracts in English
