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New insight studies of the secondary phase formation under repository conditions

Published online by Cambridge University Press:  17 February 2020

N. Rodríguez-Villagra*
Affiliation:
Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Av. Complutense, 40, 28040 Madrid, Spain
L.J. Bonales
Affiliation:
Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Av. Complutense, 40, 28040 Madrid, Spain
J. Cobos
Affiliation:
Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Av. Complutense, 40, 28040 Madrid, Spain
*
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Abstract

In a deep geological repository (DGR) scenario, uranium oxidized in aqueous systems will be stabilized as UO22+ (hexavalent uranium), as a consequence of tetravalent uranium oxidation by radiolytic byproducts. Uranyl cationic species (UO22+) in different speciation forms are expected to be found at the whole pH range conditions. The importance of UO22+ lies in its potential incorporation of trace radioelements onto secondary uranyl phases. In view of the difficulty of U chemistry in natural groundwater, it is necessary to improve speciation assessment techniques so as to understand chemical processes. Raman spectroscopy has been shown as a powerful tool to analyze the speciation of various actinyl (UO22+,NpO2+ and PuO22+) and to determine the distribution of those elements which are more likely to be stable in a near-field groundwater environment. Therefore, the aim of this work is to follow UO22+ changes as a consequence of γ radiation in aqueous media under DGR conditions, and to understand the behavior of UO22+ as a function of aqueous media, which help to understand and predict the potential precipitation of the solid phases formed. In this work, the use of Raman spectroscopy adapted to the empirical analysis of different nuclear applications for initial uranium concentrations 0.04M at ambient atmosphere is shown, i.e. as monitoring tool for UO22+ precipitation as a function of pH, studying UO2(NO3)2·6H2O stability in aqueous solutions representative of groundwater, in particular at ionic strength I = 0.02 – 0.4 M and pH from 7 to 13.2; and to evaluate the effect of γ radiation fields. At 10−4-10-3 M of radiolytically formed H2O2 concentration, the amount of uranium in solution decreased, as a results of secondary phases precipitation. The results obtained will be useful to the performance assessment studies of the Spent Nuclear Fuel (SNF) stored in DGRs. The work performed provides a partial picture of secondary phase formations, as a result of corrosion of SNF in a DGR.

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Articles
Copyright
Copyright © Materials Research Society 2020

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References

REFERENCES

Broczkowski, M. E., Noel, J. J., and Shoesmith, D. W., "The inhibiting effects of hydrogen on the corrosion of uranium dioxide under nuclear waste disposal conditions.," J. Nuc. Mat. , vol. 346, pp. 16-23, 2005/11/1 2005.CrossRefGoogle Scholar
Rudnicki, J. D., Russo, R. E., and Shoesmith, D. W., "Photothermal deflection spectroscopy investigations of uranium dioxide oxidation," J. Electroanal. Chem. , vol. 372, pp. 63-74, 1994/7/8 1994.CrossRefGoogle Scholar
Amme, M., Pehrman, R., Deutsch, R., Roth, O., and Jonsson, M., "Combined effects of Fe(II) and oxidizing radiolysis products on UO2 and PuO2 dissolution in a system containing solid UO2 and PuO2," J. Nucl. Mat. , vol. 430, pp. 1-5, 2012/11/01/ 2012.CrossRefGoogle Scholar
Yakabuskie, P. A., "The Influence of Long-Term Gamma-Radiation and Initially Dissolved Chemicals on Aqueous Kinetics and Interfacial Processes," The University of Western Ontario, London, Ontario, Canada 2014.Google Scholar
Draganic, I., The Radiation Chemistry of Water vol. 26, 1971.Google Scholar
Dzaugis, M. E., Spivack, A. J., and D’Hondt, S., "A quantitative model of water radiolysis and chemical production rates near radionuclide-containing solids," Radiation Physics and Chemistry , vol. 115, pp. 127-134, 2015/10/01/ 2015.CrossRefGoogle ScholarPubMed
Hanson, B., McNamara, B., Buck, E., Friese, J., Jenson, E., Krupka, K., et al. , "Corrosion of comercial spent nuclear fuel. 1. Formation of studtite and metastudtite," Radiochimica Acta , vol. 93, pp. 159-168, 2005.CrossRefGoogle Scholar
Golovich, E. C., Wellman, D. M., Serne, R. J., and Bovaird, C. C., "Summary of Uranium Solubility Studies in Concrete Waste Forms and Vadose Zone Environments," Pacific Northwest National Laboratory, Richland, Washington2011.CrossRefGoogle Scholar
Brownsword, M., Buchan, A. B., Ewart, F. T., McCrohon, R., Ormerod, G. J., Smith-Briggs, J. L., et al. , "The Solubility and Sorption of Uranium (VI) in a Cementitious Repository," MRS Proceedings , vol. 176, p. 577, 2011.CrossRefGoogle Scholar
Glasser, F. P., Rahman, A. A., Macphee, D., McCulloch, C. E., and Angus, M. J., "Immobilization of radioactive waste in cement based matrices," United Kingdom1985.Google Scholar
Zhao, P., Allen, P. G., Sylwester, E. R., and Viani, B. E., "The partitioning of uranium and neptunium onto hydrothermally altered concrete," Radioch. Acta , vol. 88, pp. 729 - 738, 1999.Google Scholar
Lu, G., Forbes, T. Z., and Haes, A. J., "Evaluating Best Practices in Raman Spectral Analysis for Uranium Speciation and Relative Abundance in Aqueous Solutions," Analytical Chemistry , vol. 88, pp. 773-780, 2016/01/052016.CrossRefGoogle ScholarPubMed
Lu, G., Haes, A. J., and Forbes, T. Z., "Detection and identification of solids, surfaces, and solutions of uranium using vibrational spectroscopy," Coordination chemistry reviews , vol. 374, pp. 314-344, 2018.CrossRefGoogle ScholarPubMed
Spinks, J. W. T. and Woods, R. J., "An introduction to radiation chemistry," 1990.Google Scholar
Christensen, H. and Sunder, S., "Current state of knowledge of water radiolysis effects on spent nuclear fuel corrosion," Nuclear Technology , vol. 131, pp. 102-123, Jul 2000.CrossRefGoogle Scholar
Christensen, H., "Calculations simulating spent-fuel leaching experiments," Nucl. Technology , vol. 124, pp. 165-174, 1998.Google Scholar
Sunder, S. and Christensen, H., "Gamma Radiolysis of Water Solutions Relevant to the Nuclear Fuel Waste Managament Program," Nucl. Technology , vol. 104, p. 403, 1993.CrossRefGoogle Scholar
Iwamatsu, K., Sundin, S., and LaVerne, J. A., "Hydrogen peroxide kinetics in water radiolysis," Radiation Physics and Chemistry , vol. 145, pp. 207-212, 2018/04/01/ 2018.CrossRefGoogle Scholar
Carver, M. B., Hanley, D. V., and Chaplin, K. R., "Maksima Chemist. A program for mass action kinetics simulation by automatic chemical equation manipulation and integration by using Stiff techniques," AECL, Chalk River, Ontario AECL- 6413, 1979.Google Scholar
Jégou, C., Muzeau, B., Broudic, V., Peuget, S., Poulesquen, A., Roudil, D., et al. , "Effect of external gamma irradiation on dissolution of the spent UO2 fuel matrix," J. Nuc. Mat. , vol. 341, pp. 62-82, 2005.CrossRefGoogle Scholar
Nicoll, W. D. and Smith, A. F., "Stability of Dilute Alkaline Solutions of Hydrogen Peroxide," Industrial & Engineering Chemistry , vol. 47, pp. 2548-2554, 1955/12/01 1955.CrossRefGoogle Scholar
Horne, G. P., Donoclift, T. A., Sims, H. E., Orr, R. M., and Pimblott, S. M., "Multi-Scale Modeling of the Gamma Radiolysis of Nitrate Solutions," J. Phys. Chem. B , vol. 120, pp. 11781-11789, 2016/11/17 2016.CrossRefGoogle ScholarPubMed
Tomažić, B., Branica, M., and Težak, B., "Precipitation and Hydrolysis of Uranium(VI) in Aqueous Solutions: Uranyl Nitrate-Potassium Hydroxide-Neutral Electrolyte," Croat. Chem. Acta , vol. 34, pp. 41-50, 1962.Google Scholar
A Djogić, R., Cuculić, V., and Branica, M., "Precipitation of Uranium(VI) Peroxide (UO4) in Sodium Perchlorate Solution," Croat. Chem. Acta , vol. 78, pp. 575-580, 2005.Google Scholar
Gorman-Lewis, D., Burns, P. C., and Fein, J. B., "Review of uranyl mineral solubility measurements," J. Chem. Thermod. , vol. 40 pp. 335-352, 2008.CrossRefGoogle Scholar
Guillaumont, R., Fanghänel, T., Fuger, J., Grenthe, I., Neck, V., Palmer, D. A., et al. , Update on the Chemical Thermodynamics of Uranium, Neptunium, Plutonium, Americium and Technetium vol. 5. Amsterdam. Boston. Heilderberg. London. New York. Oxford. Paris. San Diego. San Francisco. Singapore. Sydney. Tokyo: Elsevier B.V., 2003.Google Scholar
Kim, J., Kim, H., Kim, W.-S., and Um, W., "Dissolution of studtite [UO2(O2)(H2O)4] in various geochemical conditions," J. Environm. Rad. , vol. 189, pp. 57-66, 2018/09/01/ 2018.CrossRefGoogle Scholar
Tokunaga, T. K., Kim, Y., Wan, J., and Yang, L., "Aqueous Uranium(VI) Concentrations Controlled by Calcium Uranyl Vanadate Precipitates," Environmental Science & Technology , vol. 46, pp. 7471-7477, 2012/07/17 2012.CrossRefGoogle ScholarPubMed