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Journal Articles

Matrix diffusion and sorption of Cs$$^{+}$$, Na$$^{+}$$, I$$^{-}$$ and HTO in granodiorite; Laboratory-scale results and their extrapolation to the in situ condition

Tachi, Yukio; Ebina, Takanori*; Takeda, Chizuko*; Saito, Toshihiko*; Takahashi, Hiroaki*; Ouchi, Yuji*; Martin, A. J.*

Journal of Contaminant Hydrology, 179, p.10 - 24, 2015/08

 Times Cited Count:27 Percentile:78.93(Environmental Sciences)

Matrix diffusion and sorption are important processes in the assessment of radionuclide transport in crystalline rocks. Diffusion and sorption parameters for Cs$$^{+}$$, Na$$^{+}$$, I$$^{-}$$ and HTO were determined by through-diffusion and batch sorption experiments using granodiorite samples from the Grimsel Test Site, Switzerland. The De values were in the order Cs$$^{+}$$, Na$$^{+}$$, HTO, I$$^{-}$$. The capacity factor and Kd values show the same trends. The dual depth profiles for Cs$$^{+}$$ and Na$$^{+}$$ can be interpreted by a near-surface Kd increment. The microscopic analysis indicated that this is caused by high porosity and sorption capacities in disturbed biotite minerals on the sample surface. The Kd values derived from the dual profiles are likely to correspond to Kd dependence on the grain sizes of crushed samples in the batch experiments. The results of the in situ LTD experiments were interpreted reasonably well by using transport parameters derived from laboratory data and extrapolating them to in situ conditions.

Journal Articles

Comparative modeling of an in situ diffusion experiment in granite at the Grimsel Test Site

Soler, J. M.*; Landa, J.*; Havlov$'a$, V.*; Tachi, Yukio; Ebina, Takanori*; Sardini, P.*; Siitari-Kauppi, M.*; Eikenberg, J.*; Martin, A. J.*

Journal of Contaminant Hydrology, 179, p.89 - 101, 2015/08

 Times Cited Count:33 Percentile:84.06(Environmental Sciences)

Matrix diffusion is a key process for radionuclide retention in crystalline rocks. An in-situ diffusion experiment in granite matrix was performed at the Grimsel Test Site (Switzerland). Several tracers (HTO, Na$$^{+}$$, Cs$$^{+}$$) were circulated through a borehole and the decrease in tracer concentrations was monitored for 2.5 years. Then, the borehole section was overcored and the tracer profiles in the rock were analyzed. Transport distances in the rock were 20 cm for HTO, 10 cm for Na$$^{+}$$ and 1 cm for Cs$$^{+}$$. The dataset was analyzed with diffusion-sorption models by different teams using different codes, with the goal of obtaining effective diffusivities (De) and rock capacity factors. There was a rather good agreement between the values from different teams, implied that De and capacity factors in the borehole damaged zone are larger than those in the bulk rock. However, HTO seems to display large discrepancies between measured and modeled results.

Journal Articles

Evaluation of uncertainties originating from the different modeling approaches applied to analyze regional groundwater flow in the Tono area of Japan

Ijiri, Yuji*; Saegusa, Hiromitsu; Sawada, Atsushi; Ono, Makoto*; Watanabe, Kunio*; Karasaki, Kenji*; Doughty, C.*; Shimo, Michito*; Fumimura, Kenichi*

Journal of Contaminant Hydrology, 103(3-4), p.168 - 181, 2009/01

 Times Cited Count:8 Percentile:29.63(Environmental Sciences)

Qualitative evaluation of the effects of uncertainties originating from scenario development, conceptual models, and parameter values is an important subject in the area of safety assessment for high-level nuclear waste disposal. In this study, regional-scale groundwater flow analyses for the Tono area, Japan were conducted using three continuous models which were designed to handle heterogeneous porous media. We evaluated the simulation results to quantitatively analyze uncertainties originating from conceptual models. We found that uncertainties originating from conceptual models (1) greatly depend on boundary conditions and hydrological structures to be modeled, which are assigned by modelers, and (2) are larger than uncertainties originating from the variance in realizations of the Monte Carlo method in stochastic modeling.

Journal Articles

Use of X-ray absorption imaging to examine heterogeneous diffusion in fractured crystalline rocks

Uchida, Masahiro

Journal of Contaminant Hydrology, 69(1-2), p.1 - 26, 2004/00

 Times Cited Count:22 Percentile:51.45(Environmental Sciences)

None

Journal Articles

Diffusion and Migration of Ions in Sedimentary Rock Matrix: Thermodynamic Properties of Porewater in Sandstone

Sato, Haruo

Journal of Contaminant Hydrology, 0 Pages, 2003/00

The thermodynamic properties (activity, relative partial molar Gibbs free energy, enthalpy and entropy) of porewater in sandstone were obtained as a function of water content and temperature by vapor pressure measurements.

Journal Articles

Influence of the Mode of Matrix Porosity Determination on Matrix Diffusion Calculations; Laboratory Data Relevant to in Situ Conditions?

; Alexander, W. R.*; Frieg, B.*; Schild M*

Journal of Contaminant Hydrology, 61, p.131 - 145, 2002/00

 Times Cited Count:23 Percentile:50.64(Environmental Sciences)

None

Journal Articles

Apparent diffusion coefficients and chemical species of neptunium(V) in compacted na-montmorillonite

Kozai, Naofumi; Inada, Koichi*; Kozaki, Tamotsu*; Sato, Seichi*; Ohashi, Hiroshi*; Bamba, Tsunetaka

Journal of Contaminant Hydrology, 47(2-4), p.149 - 158, 2001/02

 Times Cited Count:15 Percentile:43.35(Environmental Sciences)

no abstracts in English

Journal Articles

Development and testing of radionuclide transport models for fractured rock; Examples from the Nagra/JNC Radionuclide Migration Programme in the Grimsel Test Site, Switzerland

; W.R.Alexan*; W.Kickmaie*; Frieg, B.*; McKinl, I. G.*

Journal of Contaminant Hydrology, 47, p.335 - 348, 2001/00

 Times Cited Count:25 Percentile:58.31(Environmental Sciences)

None

Journal Articles

EXPERIMENTAL AND MODELING STUDIES ON SORPTION AND DIFFUSION OF RADIUM IN BENTONITE

; ; Sato, Haruo; Yui, Mikazu

Journal of Contaminant Hydrology, 0 Pages, 2001/00

None

Journal Articles

In situ resin impregnation for investigating radionuclide retardation in fractured repository host rocks

; W.R.Alexan*; H.Dollinge*; Ch.Buhler*; P.Haag*

Journal of Contaminant Hydrology, 35, p.115 - 130, 1999/00

 Times Cited Count:28 Percentile:63.3(Environmental Sciences)

None

Journal Articles

Hydrothermal redistribution of rare earth elements in Toki granitic rock,central Japan

; Onuki, Toshihiko; Isobe, Hiroshi; Yanase, Nobuyuki; Sekine, Keiichi; *; *

Journal of Contaminant Hydrology, 35, p.191 - 199, 1998/00

 Times Cited Count:4 Percentile:19.23(Environmental Sciences)

no abstracts in English

Journal Articles

Characteristics of Chernobyl-derived radionuclides in particulate form in surface waters in the exclusion zone around the Chernobyl Nuclear Power Plant

Matsunaga, Takeshi; Ueno, Takashi; Amano, Hikaru; Y.Tkatchenko*; A.Kovalyov*; Watanabe, Miki*; Onuma, Yoshikazu*

Journal of Contaminant Hydrology, 35, p.101 - 113, 1998/00

 Times Cited Count:42 Percentile:75.27(Environmental Sciences)

no abstracts in English

Journal Articles

Experimental study on neptunium migration under in situ geochemical conditions

Kumata, Masahiro; Vandergraaf, T. T.*

Journal of Contaminant Hydrology, 35(1-3), p.31 - 40, 1998/00

 Times Cited Count:6 Percentile:24.89(Environmental Sciences)

no abstracts in English

Journal Articles

Diffusivity of U, Pu and Am carbonate complexes in a granite from Inada, Ibaraki, Japan studied by through diffusion

Yamaguchi, Tetsuji;

Journal of Contaminant Hydrology, 35, p.55 - 65, 1998/00

 Times Cited Count:29 Percentile:64.5(Environmental Sciences)

no abstracts in English

Journal Articles

Sorption and Diffusion Behavior of Selenium in Tuff

; Shibutani, Tomoki; Sato, Haruo;

Journal of Contaminant Hydrology, 35, p.77 - 89, 1998/00

 Times Cited Count:35 Percentile:70.02(Environmental Sciences)

None

Journal Articles

Effective diffusivity of the uranyl ion in a granite from Inada, Ibaraki, Japan

Yamaguchi, Tetsuji; Sakamoto, Yoshiaki; ; T.T.Vandergraaf*

Journal of Contaminant Hydrology, 26, p.109 - 117, 1997/00

 Times Cited Count:29 Percentile:67.17(Environmental Sciences)

no abstracts in English

16 (Records 1-16 displayed on this page)
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