Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-26T23:41:13.210Z Has data issue: false hasContentIssue false

Coprecipitation Experiments Using Simulated Spent Fuel Solutions in the Presence of Metallic Iron in Synthetic Bentonitic-Granitic Water Under Oxidising Conditions

Published online by Cambridge University Press:  17 March 2011

Javier Quiñones
Affiliation:
Nuclear Fission Department, Ciemat, Avda Complutense 22. 28040 – Madrid, Spain Email:, [email protected]
Ángel González de la Huebra
Affiliation:
Nuclear Fission Department, Ciemat, Avda Complutense 22. 28040 – Madrid, Spain
Aurora Martínez Esparza
Affiliation:
ENRESA, C/ Emilio Vargas 7, 28043 – Madrid, Spain
Get access

Abstract

This paper presents the results obtained from coprecipitation experiments of uranyl solutions in the presence of metallic iron and/or its alteration phases in synthetic bentonitic-granitic composition water. Experiments were done under oxidising conditions at room temperature. The pH range covered was 7.4 – 8.8. Changes in the uranium concentrations and the characterisation of the secondary phases formed in the experiments were done using XRD and SEM-EDS and are presented herein.

Final uranium concentration values were in the range of 2·10−5 – 5·10−4 mol (kg of H2O)−1. In all cases, results from these experiments did not show evidence of a clear effect due to the presence of iron (metallic or previously corroded) on the uranium concentration. These data were similar to those obtained by coprecipitation in similar conditions but in absence of iron material. Boltwoodite was observed [K2(UO2)2(SiO3)2(OH)2·3H2O] in iron surface materials and characterized in all experiments. Based on the experimental data obtained (uranium concentration in solution and bulk solid phase characterisation) we propose the following surface-mediated reaction:

2 K+ + 2 H4SiO4 + 2 UO2+2 + 3 H2O ⇔ K2(UO2)2(SiO3)2(OH)2·3H2O + 6 H+

Type
Research Article
Copyright
Copyright © Materials Research Society 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Liger, E., Charlet, L., and Cappellen, P. Van, Geochimica et Cosmochimica Acta, 63, 29392955 (1999).Google Scholar
[2] Bruno, J., Pablo, J. de, Duro, L., and Figuerola, E., Geochimica et Cosmochimica Acta, 59, 41134123 (1995).Google Scholar
[3] Stumm, W. and Sulzberger, B., Geochimica et Cosmochimica Acta, 56, 32333257 (1992).Google Scholar
[4] Lucuta, P. G., Balmer, B. J., Matzke, H. j., and Hartwig, D. S., Atomic Energy of Canada Limited AECL-1017, (1989).Google Scholar
[5] Martinez, B., Melon, A., and Valladares, J., in Informes Técnicos, PR-X8-01. Madrid: Ciemat (1996).Google Scholar
[6] Quiñones, J., Grambow, B., Loida, A., and Geckeis, H., J. Nucl. Mater., 238, 38 (1996).Google Scholar
[7] Quiñones, J., Serrano, J. A., and Arocas, P. P. Díaz, J. Nucl. Mater., 298, 6368 (2001).Google Scholar
[8] Grambow, B. and Müller, R., 176: Materials Research Society (1990).Google Scholar
[9] Quiñones, J., Serrano, J. A., Arocas, P. P. Díaz, Almazán, J. L. Rodríguez, Cobos, J., Esteban, J. A., and Esparza, A. Martínez, in Scientific Basis for Nuclear Waste Management XXIV, 663, Mat. Res. Soc. Symp. Proc., Hart, K. P. and Lumpkin, G. R., Eds.: The Materials Research Society, 435–439 (2001).Google Scholar
[10] Quiñones, J., Agejas, J. A. Serrano, Arocas, P. P. Díaz, Cobos, J., Almazán, J. L. Rodríguez, Esparza, A. Martínez, and Esteban, J. A., presented at WM'99, Tucson, Arizona, USA (1999).Google Scholar
[11] Behrends, T. and Cappellen, P. Van, Journal of Conference Abstract s, 5, 207 (2000).Google Scholar
[12] Aamrani, F. El, Casas, I., Pablo, J. de, Duro, L., Grivé, M., and Bruno, J., in SKB Technical Report, 99-21: SKB (1999).Google Scholar
[13] Khamskii, E. V.. New York - London: Edt. Consultants Bureau (1969).Google Scholar
[14] Walton, A. G.: Interscience Publishers John Wiley & Sons (1967).Google Scholar
[15] Wronkiewicz, D. J., Bates, J. K., Wolf, S. F., and Buck, E. C., J. Nucl. Mater., 238, 7895 (1996).Google Scholar
[16] Finn, P. A., Finch, R. J., Buck, E. C., and Bates, J., in Scientific Basis for Nuclear Waste Management XXI, 506, Mat. Res. Soc. Symp. Proc., McKinley, I. G. and McCombie, C., Eds.: The Materials Research Society, 123131 (1998).Google Scholar
[17] Finch, R. J., Buck, E. C., Finn, P. A., and Bates, J. K., in Scientific Basis for Nuclear Waste Management XXII, 556, Mat. Res. Soc. Symp. Proc., Wronkiewicz, D. J. and Lee, J. H., Eds.: The Materials Research Society, 431438 (1999).Google Scholar
[18] Burns, P. C., The Canadian Mineralogist, 36, 10691075 (1998).Google Scholar