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Solution Chemistry for Actinide Borate Species to High Ionic Strengths: Equilibrium Constants for AmHB4O72+ And AmB9O13(OH)4(cr) and Their Importance to Nuclear Waste Management

Published online by Cambridge University Press:  20 March 2017

Yongliang Xiong
Yongliang Xiong*
Affiliation:
Sandia National Laboratories (SNL), Carlsbad Programs Group, 4100 National Parks Highway, Carlsbad, NM 88220, USA
*
*(e-mail: yxiong@sandia.gov)
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Abstract

Borate is present in natural groundwaters and borate is also released into groundwaters when borosilicate glass, waste form for high level nuclear waste, is corroded. Borate can form an aqueous complex, AmHB4O72+, with actinides in +III oxidation state. In this work, we present our evaluation of the equilibrium constant for formation of AmHB4O72+ and the associated Pitzer interaction parameters at 25°C.

Using Nd(III) as an analog to Am(III), solubility data of Nd(OH)3(s) in NaCl solutions in the presence of borate ion from the literature, is used to determine Am(III) interactions with borate. The log10K for the formation reaction is 37.34. This evaluation is in accordance with the Waste Isolation Pilot Plant (WIPP) thermodynamic model in which the borate species include B(OH)3(aq), B(OH)4–, B3O3(OH)4–, B4O5(OH)42–, and NaB(OH)4(aq). The WIPP thermodynamic database uses the Pitzer model to calculate activity coefficients of aqueous species.

In addition, the equilibrium constant for dissolution of AmB9O13(OH)4(cr) at 25oC is evaluated from the solubility data on NdB9O13(OH)4(cr) in NaCl solutions, again using Nd(III) as an analog to Am(III). The log10K for the dissolution reaction is –79.30. In the evaluation for log10K for the dissolution reaction, AmHB4O72+ is also considered.

The equilibrium constant and Pitzer parameters evaluated by this study will be important to describe the chemical behavior of Am(III) in the presence of borate in geological repositories.

Keywords

chemical reactionBactinide
Type
Articles
Information
MRS Advances , Volume 2 , Issue 13: Scientific Basis for Nuclear Waste Management XL , 2017 , pp. 741 - 746
Copyright
Copyright © Materials Research Society 2017 

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References

REFERENCES

Vengosh, A., Starinsky, A., Kolodny, Y., and Chivas, A.R., Geochimica et Cosmochimica Acta 55, 1689 (1991).CrossRefGoogle Scholar
Advocat, T., Jollivet, P., Crovisier, J.L., del Nero, M., Journal of Nuclear Materials 298, 55 (2001).CrossRefGoogle Scholar
Curti, E., Dahn, R., Farges, F., and Vespa, M., Geochimica et Cosmochimica Acta 73, 2283 (2009)CrossRefGoogle Scholar
Borkowski, M., Richmann, M., Reed, D.T., and Xiong, Y.-L., , Y.-L., Radiochimica Acta 98, 577 (2010).CrossRefGoogle Scholar
Schott, J., Kretzschmar, J., Acker, M., Eidner, S., Kumke, M.U., Drobot, B., Barkleit, A., Taut, S., Brendler, V., and Stumpf, T., , T., Dalton Transactions 43, 11516 (2014).CrossRefGoogle Scholar
Schott, J., Kretzschmar, J., Tsushima, S., Drobot, B., Acker, M., Barkleit, A., Taut, S., Brendler, V., and Stumpf, T., , T., Dalton Transactions 44, 11095 (2015).CrossRefGoogle Scholar
Wang, S.-A., Alekseev, E.V, Depmeier, W., and Albrecht-Schmitt, T.E., Inorganic Chemistry 50, 2079 (2010).CrossRefGoogle Scholar
Wang, S.-A., Alekseev, E.V, Depmeier, W., and Albrecht-Schmitt, T.E., Chemical Communications 47, 10874 (2011).CrossRefGoogle Scholar
Hinz, K., Altmaier, M., Gaona, X., Rabung, T., Schild, D., Richmann, M., Reed, D.T., Alekseev, E.V., and Geckeis, H., , H., New journal of chemistry 39, 849 (2015).CrossRefGoogle Scholar
Xiong, Y.-L., and Lord, A.C.S., Applied Geochemistry 23, 1634 (2008).CrossRefGoogle Scholar
Wolery, T.W., Xiong, Y.-L., and Long, J., , J., “Verification and Validation Plan/Validation Document for EQ3/6 Version 8.0a for Actinide Chemistry, Document Version 8.10.” Carlsbad, NM: Sandia National laboratories, ERMS 550239, 2010.Google Scholar
Xiong, Y.-L., “WIPP Verification and Validation Plan/Validation Document for EQ3/6 Version 8.0a for Actinide Chemistry, Revision 1, Document Version 8.20. Supersedes ERMS 550239.” Carlsbad, NM. Sandia National Laboratories, ERMS 555358, 2011.Google Scholar
Xiong, Y.-L., Nowak, J., Brush, L.H., Ismail, A.E., Long, J.J., Materials Research Society Symposium Proceedings 1265, 15(2010).CrossRefGoogle Scholar
Xiong, Y.-L., Journal of Solution Chemistry 42, 139 (2013).CrossRefGoogle Scholar
Xiong, Y.-L., American Mineralogist 98, 141 (2013).CrossRefGoogle Scholar
Xiong, Y.-L., Chemical Geology 373, 37 (2014).CrossRefGoogle Scholar
Xiong, Y.-L., Monatshefte fur Chemie - Chemical Monthly 146, 1433 (2015).CrossRefGoogle Scholar
Domski, P.S., “Memo AP-173, EQ3/6 Database Update: DATA0.FM2” Memorandum to WIPP Records, October 27, 2015. Carlsbad, NM: Sandia National Laboratories. ERMS 564914, 2015.Google Scholar
Xiong, Y.-L., Domski, P.S., , P.S., “Updating the WIPP Thermodynamic Database, Revision 1, Supersedes ERMS 565730.” Carlsbad, NM: Sandia National Laboratories. ERMS 566047, 2016.Google Scholar
Felmy, A.R., and Weare, J.H., Geochimica et Cosmochimica Acta 50, 2771 (1986).CrossRefGoogle Scholar
Xiong, Y-L., Kirkes, L., and Westfall, T., American Mineralogist 98, 2030 (2013).CrossRefGoogle Scholar