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Journal Articles

None

Matsubara, Ryuta*; Hamamoto, Takafumi*; Ishidera, Takamitsu

NUMO-TR-24-03, p.65 - 70, 2024/10

no abstracts in English

Journal Articles

None

Hamamoto, Takafumi*; Koike, Ayaka*; Ishidera, Takamitsu; Iwata, Hajime; Fukatsu, Yuta; Taneichi, Yayoi

NUMO-TR-24-03, p.85 - 86, 2024/10

no abstracts in English

Journal Articles

Trivalent lanthanide sorption onto illite in the presence of carbonate; A Study combining thermodynamic sorption modeling, time-resolved laser fluorescence spectroscopy, and parallel factor analysis

Sugiura, Yuki; Ishidera, Takamitsu; Aoyagi, Noboru; Mei, H.; Saito, Takumi*; Tachi, Yukio

Applied Clay Science, 258, p.107476_1 - 107476_10, 2024/09

 Times Cited Count:2 Percentile:51.28(Chemistry, Physical)

Journal Articles

Evaluation of thermodynamic model of Pd(II) complex formation with isosaccharinic acid

Kimuro, Shingo; Taneichi, Yayoi; Iwata, Hajime; Ishidera, Takamitsu; Kitamura, Akira; Tachi, Yukio; Tanaka, Takeru*; Hirano, Kana*; Hieda, Manami*; Miyabe, Shunsuke*; et al.

Journal of Solution Chemistry, 53(6), p.854 - 868, 2024/06

 Times Cited Count:0 Percentile:0.00(Chemistry, Physical)

Journal Articles

Long-term alteration behavior of buffer material by the interaction with overpack and cement

Hamamoto, Takafumi*; Ishidera, Takamitsu; Sasamoto, Hiroshi

NUMO-TR-24-01, p.87 - 90, 2024/05

no abstracts in English

Journal Articles

Evaluation of the effects of bentonite colloids

Matsubara, Ryuta*; Hamamoto, Takafumi*; Ishidera, Takamitsu

NUMO-TR-24-01, p.91 - 94, 2024/05

no abstracts in English

Journal Articles

Development of the methodology for setting radionuclide migration parameters reflecting site investigations and data acquisition

Hamamoto, Takafumi*; Ishidera, Takamitsu; Tachi, Yukio

NUMO-TR-24-01, p.102 - 103, 2024/05

no abstracts in English

Journal Articles

A Raman spectroscopy study of bicarbonate effects on UO$$_{2+x}$$

McGrady, J.; Kumagai, Yuta; Watanabe, Masayuki; Kirishima, Akira*; Akiyama, Daisuke*; Kimuro, Shingo; Ishidera, Takamitsu

Journal of Nuclear Science and Technology, 60(12), p.1586 - 1594, 2023/12

 Times Cited Count:2 Percentile:46.61(Nuclear Science & Technology)

Journal Articles

Sorption of Sn and Nb on montmorillonite at neutral to alkaline pH

Ishidera, Takamitsu; Okazaki, Mitsuhiro*; Yamada, Yoshihide*; Tomura, Tsutomu*; Shibutani, Sanae*

Journal of Nuclear Science and Technology, 60(5), p.536 - 546, 2023/05

 Times Cited Count:2 Percentile:29.47(Nuclear Science & Technology)

The distribution coefficient (${it K$_{d}$}$) value of radionuclides is an important parameter in the radionuclide migration analysis in the safety assessment of the geological disposal of high-level radioactive waste. The ${it K$_{d}$}$ values must be extensively evaluated especially under conditions where they might be decreased to improve the reliability of safety assessment. In this study, the pH dependence of the ${it K$_{d}$}$ values for Sn and Nb on montmorillonite was evaluated using batch sorption experiments at neutral to alkaline pH, which might be caused by the leaching of cementitious materials and the corrosion of carbon steel. The ${it K$_{d}$}$ values were determined in the range 8 $$<$$ pH $$<$$ 12 by the experiments and were found to decrease with increasing pH. A model calculation using a thermodynamic sorption model was conducted on the measured pH dependence of the ${it K$_{d}$}$ values. Two different sorption sites were required to describe the pH dependence of the ${it K$_{d}$}$ values of Sn in the model calculation, whereas one sorption site was considered predominant in the sorption of Nb.

Journal Articles

None

Hamamoto, Takafumi*; Ishida, Keisuke*; Ishidera, Takamitsu

NUMO-TR-22-02, p.58 - 61, 2023/03

no abstracts in English

Journal Articles

None

Hamamoto, Takafumi*; Ishida, Keisuke*; Ishidera, Takamitsu; Tachi, Yukio

NUMO-TR-22-02, p.88 - 89, 2023/03

no abstracts in English

Journal Articles

None

Ichikawa, Nozomi*; Hamamoto, Takafumi*; Ishidera, Takamitsu; Sasamoto, Hiroshi

NUMO-TR-22-02, p.55 - 57, 2023/03

no abstracts in English

Journal Articles

Effects of buried environment on corrosion of iron artifacts excavated from Heijo Palace Site; Examination of the chloride salt accumulation inside of an iron artifact in soil

Yanagida, Akinobu*; Ura, Yoko*; Mitsui, Seiichiro; Ishidera, Takamitsu; Kawakita, Ryohei

Nara Bunkazai Kenkyujo Soritsu 70-Shunen Kinen Rombunshu; Bunkazai Ronso 5, p.843 - 856, 2023/03

To investigate chloride salt accumulation inside an iron artifact in soil, non-destructive analysis of three iron artifacts excavated from the Heijo Palace Site was conducted using elemental mapping by X-ray fluorescence analysis, micro-X-ray diffraction analysis, and X-ray computed tomography. Furthermore, the buried environments of the artifacts were presumed based on the previous reports of the environmental investigation at the Heijo Palace site. The results revealed the iron artifact's corrosion behavior was different individually- (1) the iron artifact that was presumed buried under oxidation environments had a goethite/magnetite corrosion layer and contained akageneite inside the corrosion layer. (2) the metal of the other iron artifacts buried under the oxidation environment had eluted absolutely and the artifacts had a rust layer formed by only goethite. (3) the other artifact buried in reduction environments had a rust layer composed of siderite. Accumulation of chloride salts inside an iron artifact was observed only in (1). Because each Cl$$^{-}$$ concentration measured in underground water observation holes at the Heijo Palace Site showed almost the same level concentrations, it was presumed that the accumulation of chloride salts depended on the environmental factor except for Cl$$^{-}$$ concentration. Based on these results, there was a possibility that the occurrence of local corrosion attributed to the separation of anodic and cathodic regions through the formation of the goethite/magnetite rust layer caused chloride salts accumulation inside an iron artifact.

Journal Articles

Selenide [Se(-II)] immobilization in anoxic, Fe(II)-rich environments; Coprecipitation and behavior during phase transformations

Francisco, P. C. M.; Matsumura, Daiju; Kikuchi, Ryosuke*; Ishidera, Takamitsu; Tachi, Yukio

Environmental Science & Technology, 56(5), p.3011 - 3020, 2022/03

 Times Cited Count:2 Percentile:12.53(Engineering, Environmental)

Journal Articles

Diffusion of acetic acid, butyric acid, and butanol in compacted montmorillonite

Ishidera, Takamitsu

Journal of Radioanalytical and Nuclear Chemistry, 330(1), p.149 - 158, 2021/10

 Times Cited Count:2 Percentile:20.79(Chemistry, Analytical)

Journal Articles

Development of evaluation method for diffusion and filtration behavior of colloid in compacted bentonites using dendrimers

Endo, Takashi*; Tachi, Yukio; Ishidera, Takamitsu; Terashima, Motoki

Nihon Genshiryoku Gakkai Wabun Rombunshi, 20(1), p.9 - 22, 2021/03

Evaluation method of colloid diffusion and filtration in compacted bentonites was developed using dendrimers. Diffusion and filtration behavior of PAMAM dendrimers with the size of 5.7$$sim$$7.2nm was investigated by the through-diffusion experiment in bentonite compacted to 0.8 Mg/m$$^{3}$$ and saturated with 0.005$$sim$$0.5mol/L NaCl. Effective diffusivities (De) and filtration ratios (Rf) of dendrimers were determined from the breakthrough curves and the depth profiles in compacted bentonite, respectively. The De values of negatively charged dendrimer increased when porewater salinity increased and dendrimer size decreased as influenced by anion exclusion effect in negatively charged clay surfaces. The Rf values increased when porewater salinity decreased and dendrimer size increased, demonstrating significant fractions of dendrimer were filtered by narrow pores in complex pore networks. These trends consistent with the previous studies emphasize the validity of the evaluation method using dendrimer.

Journal Articles

Surface complexation of Ca and competitive sorption of divalent cations on montmorillonite under alkaline conditions

Sugiura, Yuki; Ishidera, Takamitsu; Tachi, Yukio

Applied Clay Science, 200, p.105910_1 - 105910_10, 2021/01

 Times Cited Count:14 Percentile:75.75(Chemistry, Physical)

Journal Articles

Key factors controlling radiocesium sorption and fixation in river sediments around the Fukushima Daiichi Nuclear Power Plant, 2; Sorption and fixation behaviors and their relationship to sediment properties

Tachi, Yukio; Sato, Tomofumi*; Takeda, Chizuko*; Ishidera, Takamitsu; Fujiwara, Kenso; Iijima, Kazuki

Science of the Total Environment, 724, p.138097_1 - 138097_10, 2020/07

 Times Cited Count:13 Percentile:45.76(Environmental Sciences)

To understand and predict radiocesium transport behaviors in the environment, sorption and fixation behaviors of radiocesium on river sediments from Ukedo and Odaka rivers around the Fukushima Daiichi Nuclear Power Plant were investigated systematically focusing on Cs sorption and fixation mechanisms and their relationship with Cs concentrations and sediment properties including clay mineralogy and organic matter.

Journal Articles

Sorption behavior of selenide on montmorillonite

Sugiura, Yuki; Tomura, Tsutomu*; Ishidera, Takamitsu; Doi, Reisuke; Francisco, P. C. M.; Shiwaku, Hideaki; Kobayashi, Toru; Matsumura, Daiju; Takahashi, Yoshio*; Tachi, Yukio

Journal of Radioanalytical and Nuclear Chemistry, 324(2), p.615 - 622, 2020/05

 Times Cited Count:5 Percentile:35.32(Chemistry, Analytical)

Journal Articles

Interaction of Fe$$^{rm II}$$ and Si under anoxic and reducing conditions; Structural characteristics of ferrous silicate co-precipitates

Francisco, P. C. M.; Mitsui, Seiichiro; Ishidera, Takamitsu; Tachi, Yukio; Doi, Reisuke; Shiwaku, Hideaki

Geochimica et Cosmochimica Acta, 270, p.1 - 20, 2020/02

 Times Cited Count:19 Percentile:74.11(Geochemistry & Geophysics)

80 (Records 1-20 displayed on this page)