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Diffusion Behavior for Se and Zr in Sodium-Bentonite

Published online by Cambridge University Press:  15 February 2011

Haruo Sato
Affiliation:
Power Reactor and Nuclear Fuel Development Corporation, 4–33 Muramatsu, Tokai-mura, Ibaraki-ken 319–11, Japan
Mikazu Yui
Affiliation:
Power Reactor and Nuclear Fuel Development Corporation, 4–33 Muramatsu, Tokai-mura, Ibaraki-ken 319–11, Japan
Hideki Yoshikawa
Affiliation:
Power Reactor and Nuclear Fuel Development Corporation, 4–33 Muramatsu, Tokai-mura, Ibaraki-ken 319–11, Japan
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Abstract

Apparent diffusion coefficients for Se and Zr in bentonite were measured by in-diffusion method at room temperature using water-saturated sodium-bentonite. KunigelVl® * containing 50wt% Na-smectite as a major mineral was used as the bentonite material. The experiments were carried out in the dry density range of 400–1800kg/m3. Bentonite samples were immersed with distilled water and saturated before the experiments. The experiments for Se were carried out under N2 atmospheric condition (O2: 2.5ppm). Those for Zr were carried out under aerobic condition. The apparent diffusion coefficients decrease with increasing density of the bentonite. Since dominant species of Se in the pore water is predicted SeO32-, Se may be retarded by anion-exclusion because of negative charge on the surface of the bentonite and little sorption. The dominant species of Zr in the porewater is predicted Zr(OH)5- or HZrO3-. Distribution coefficient measured for Zr on the bentonite was about 1.0m3/kg from batch experiment. Therefore, the retardation may be caused by combination of the sorption and the anion-exclusion. A modelling for the diffusion mechanisms in the bentonite were discussed based on an electric double layer theory. Comparison between the apparent diffusion coefficients predicted by the model and the measured ones shows a good agreement.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

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References

REFERENCES

1. Umeki, H., Ishiguro, K., Takase, H., Yui, M., Sasaki, N., and Masuda, S., in Proceedings of High Level Radioactive Waste Management, 2, 17151733 (1991).Google Scholar
2. Sato, H., Ashida, T., Kohara, Y., and Yui, M., in Scientific Basis for Nuclear Waste ManagementXVI. edited by Interrante, C.G. and Pabalan, R.T. (Mater. Res. Soc. Proc. 294, Boston, 1992 ) pp.403408.Google Scholar
3. For example, Torstenfelt, B., Andersson, K., Kipatsi, H., Allard, B., and Olofsson, U., in Scientific Basis for Nuclear Waste ManagementV, edited by Topp, S.V. ( Mater. Res. Soc. Proc. 6, Boston, 1982) pp.295302.Google Scholar
4. PNC Technical report, PNC TN8430 93–003 (1993 )(in Japanese).Google Scholar
5. Crank, J.. The Mathematics of Diffusion. 2nd ed. (Oxford Univ. Press. London, 1975 ).Google Scholar
6. Brookins, D.G., Eh-pH Diagrams for Geochemistry, Springer-Verlag Berlin Heidelberg (1988).Google Scholar
7. Shibutani, T., Yui, M., and Yoshikawa, H., in Scientific Basis for Nuclear Waste ManagementXVII. edited by Barkatt, A. and Van Konynenburg, R.A. (Mater. Res. Soc. Proc. 333, Boston, 1993 ) pp.725730.Google Scholar
8. PNC Technical report, PNC TN8410 92–163 (1992 )(in Japanese).Google Scholar
9. Sato, H., Ashida, T., Kohara, Y., Yui, M., and Sasaki, N., Journal of Nuclear Science and Technology, 29. (9), 873882 (1992 ).Google Scholar
10. McKinley, I.G. and Hardermann, J., NAGRA Technical report NTB 84–40 (1984 ).Google Scholar
11. Cross, J.E., Ewart, F.T., and Tweed, C.J., Thermochemical Modelling with Application to Nuclear Waste Proceeding and Disposal, AERE-R12324 (1987 ).Google Scholar
12. Parkurst, D.L., Thorstenson, D.C., and Plummer, L.N., PHREEOE-A Computer Program for Geochemical Calculations, U.S. Geochemical Survey, Water-Resources Investigations 8096 (1980).Google Scholar
13. Brandberg, F. and Skagius, K., SKB Technical report, SKB 91–16 (1991 )Google Scholar
14. Taki, H., Shibutani, T., and Sato, H., Study on Distribution Coefficient for Some Rocks and Bentonite, in Proceedings of 1992 Annual Meeting at the Atomic Energy Society of Japan. C16 ( 1992 )(in Japanese ).Google Scholar
15. Muurinen, A., Diffusion of Anions and Cations in Compacted Sodium Bentonite, VTT Chemical Technology, VTT Publications 168, Technical Research Centre of Finland ESPOO (1994).Google Scholar
16. Nakano, M..“Tsuti No Busshitsu Idogaku”(Mass Transport of Soil), The University of Tokyo, Japan ( 1991 )(in Japanese ).Google Scholar
17. Kitahara, A. and Watanabe, A.,“Kaimen Denki Gensho”(Electric Phenomena at an Interface), Kyoritsu (1972 )(in Japanese).Google Scholar
18. Idemitsu, K., Furuta, H., Murayama, K., and Inagaki, Y., in Scientific Basis for Nuclear Waste ManagementXV. edited by Sombret, C.G. ( Mater. Res. Soc. Proc. 257, Strasburg, 1991 ) pp.625632.Google Scholar
19. Robinson, R.A. and Stokes, R.H., Electrolyte Solutions, The Meaurement and Interpretation of Conductance, Chemical Potential and Diffusion in Solutions of Simple Electrolytes, London Butter Worths (1959).Google Scholar
20. Kato, H., Muroi, M., Yamada, N., Ishida, H., and Sato, H., in Scientific Basis for Nuclear Waste ManagementXVIII. (Mater. Res. Soc. Proc. XXX, Kyoto, 1994 ) pp.XXX000 (to be published ).Google Scholar
21. Sasaki, Y., Shibata, M., Yui, M., and Ishikawa, H., in Scientific Basis for Nuclear Waste ManagementXVIII. (Mater. Res. Soc. Proc. XXX, Kyoto, 1994) pp.XXX000 (to be published).Google Scholar
22.Kagaku Binran” (Handbook of Chemistry), 2nd ed. The Chemical Society of Japan (1975 )(in Japanese ).Google Scholar