Radiochemical analysis of rubble and trees collected from Fukushima Daiichi Nuclear Power Station

Tanaka, Kiwamu; Shimada, Asako; Hoshi, Akiko; Yasuda, Mari; Ozawa, Mayumi; Kameo, Yutaka

Journal of Nuclear Science and Technology, 51(7-8), p.1032 - 1043, 2014/07

https://doi.org/10.1080/00223131.2014.921583

Experimental and modeling study on long-term alteration of compacted bentonite with alkaline groundwater

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

https://doi.org/10.1016/j.pce.2005.10.003

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.

Long-term alteration of bentonite; For safety evaluation of deep geological disposal

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

https://jopss.jaea.go.jp/pdfdata/JAERI-Conf-2005-007.pdf

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.

Modeling of variation in permeability of compacted bentonite with alkaline fluid for long-term safety assessment of geological disposal system

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

Development of methodlogy for the groundwater monitoring in natural barrier

Tanaka, Mayumi*; Toida, Masaru*; Atsumi, Hiroyuki*; Seno, Shoji*; Nakajima, Makoto*

no journal, , 

Ground penetrating radar with modulating frequency combined with static pressure measurement using hydrotesting tool for damaged zone, which were developed by Kajima coporation, has been applied to the drift of Tono mine for the evaluation of hydraulic characteristics of the damaged zone around the drift.

Radiochemical analysis of waste debris and stagnant water in Fukushima-1 Nuclear Power Plan, 1; Analysis of -ray emitting nuclides, H-3, C-14, Sr-90

Kameo, Yutaka; Tanaka, Kiwamu; Ozawa, Mayumi; Sato, Kenji; Unno, Toshimichi; Kimiyama, Kazuhiro; Seki, Shuhei; Hoshi, Akiko

no journal, , 

no abstracts in English