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Takebe, Shinichi; Fujiwara, Keiji*; Moriyama, Hirotake*
Nihon Genshiryoku Gakkai "Shisetsu, Kankyo Hoshano Dotai" Kenkyu Senmon Iinkai Hokokusho, p.1 - 9, 2003/03
no abstracts in English
Tachi, Yukio; Suyama, Tadahiro; Kitamura, Akira; Shibata, Masahiro; Shibutani, Sanae*; Goto, Takahiro*; Inagaki, Manabu*
no journal, ,
As part of the NUMO-JAEA collaborative research program, the methodology of parameter setting for performance assessment in preliminary investigation stage was developed and tested through the parameter setting exercises for key radionuclides sorption on rocks.
Yotsuji, Kenji; Tachi, Yukio; Hato, Shinji*
no journal, ,
We carried out the uncertainty analyses for the porewater chemistry and distribution coefficients in compacted bentonite using the PHREEQC code.
Sato, Haruo*; Niizato, Tadafumi; Tanaka, Shingo*; Abe, Hironobu; Aoki, Kazuhiro
no journal, ,
The authors derived an analytical theory for calculating apparent diffusion coefficient (D
) based on evolution of depth distribution of radiocaesium (Cs-134 and Cs-137) in soil contaminated by the Fukushima Dai-ichi Nuclear Power Plant (1F-NPP) accident in March 2011, and calculated D and distribution coefficient (K
) by analyzing evolution of depth distributions from after 3 months to after 1 year from the 1F-NPP accident. In conventional analysis, the D-values of radiocaesium in the investigations after 3 months and 1 year, 10
m
/s orders and 10
m/s orders, respectively, lowered with increasing time. The K-values, also lower than 20ml/g, largely differed from batch K-values. Similar trend is found in the Chernobyl nuclear accident. This is considered because the effect of transport by dispersion with advection of rainwater after radiocaesium deposited is included in the depth distributions. The D-values and K-values from evolutional analysis of depth distributions excluded such effect, 10
m/s orders and 10
10
ml/g, respectively, were consistent with batch K-values.
Tachi, Yukio; Akagi, Yosuke*; Nemoto, Kazuaki; Matsumoto, Kazuhiro; Ishii, Eiichi
no journal, ,
To validate radionuclide migration model in single fractures in sedimentary rocks, the mudstone sample with single fracture from Wakkanai Formation at Horonobe Underground Research Laboratory was investigated. The migration behaviors of deuterated water, iodine and cesium were measured by series of laboratory experiments including batch sorption, through-diffusion and flow-through experiments.
Ito, Miki*; Akagi, Yosuke*; Kitamura, Akira
no journal, ,
Distribution coefficient of Sn onto Na-type and Ca-type montmorillonite samples was determined under high-pH conditions with a batch method. It was suggested that sorption behavior of Sn under cementitious conditions was affected through changing major aqueous species accompanied with pH change.
Ito, Tsuyoshi*; Tachi, Yukio; Nemoto, Kazuaki*; Sato, Tomofumi*; Takeda, Masaki; Ono, Hirokazu
no journal, ,
To validate the mass transfer model in sedimentary rocks, in-situ tracer test in rock matrix was conducted at rock matrix at 350 m deep drift in the Horonobe URL. The modeling results were evaluated to be reasonable by comparing in-situ and laboratory data.
Takahashi, Yuta
no journal, ,
no abstracts in English