Abstract
In our previous studies on the optimization of glass compositions for high-level nuclear waste vitrification it was found that, over certain composition ranges, PCT leachate concentrations increased dramatically with very small changes in glass composition. The large differences that are observed between the leachate pH values for the “durable” and the “less-durable” glasses is one possible cause for this strongly non-linear glass composition effect; conversely, the pH difference may be merely another symptom. In this study, four simulated nuclear waste glasses (two of the less-durable and two of the durable types), were leached in both zwitterionic and inorganic buffer solutions, at fixed pH-values in the ranges of 7 to 12. The very different leaching behaviors of the two types of glasses persisted and, furthermore, different pH-dependence was found despite their very similar glass composition. This study suggests that the leachate pH difference observed between the less-durable and the durable glasses under uncontrolled pH conditions is tinot the major cause of the large difference of leaching behavior between those glasses. The normalized release ratios of soluble components (B, Li, Na) to Si show significant differences for the two types of glasses.
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References
J.E. Mendel, Nuclear Waste Materials Handbook - Wasteform Test Methods, DOE/TIC-11400, Materials Characterization Center, Batelle Pacific Northwest Laboratories, Richland, WA (1981).
C.M. Jantzen and N.E. Bibler, “Nuclear Waste Product Consistency Test Method Version 5.0”, WSRC-TR-90-539, Westinghouse Savannah River Company, Jan. 1992.
X. Feng, I.L. Pegg, Aa. Barkatt, P.B. Macedo, S. Cucinell and S. Lai, Nucl. Technol., 85, 334 (1989).
I.S. Muller, A.C. Buechele, I.L. Pegg, and P.B. Macedo, Mat. Res. Soc. Symp. Proc. 257, 91–98, (1992).
Aa. Barkatt, Al. Barkatt, P.E. Pehrson, P. Szoke, P.B. Macedo, Nucl. and Chem. Wast. Manag., 2, 151–164, (1981).
N.E. Good, G.D. Winget, W. Winter, T.N. Connolly, S. Izawa, and M.M. Singh, Biochem., 5, 467–477, (1966).
A. Paul, in “Chemistry of Glasses”, Chapman and Hall, 2nd ed., (1990).
R.K. Her, in “The Chemistry of Silica”, 2nd ed., John Wiley and Sons, New York, (1979).
R.J. Charles, J. Appl. Phys., 29, 1549, 1858.
J.E. Mendel, “Final Report of the Defence High-Level Waste Leaching Mechanism Program”, Pacific Northwest Laboratory Report, PNL-5157, (1984).
B. Grambow, “Nuclear Waste Glass Dissolution: Mechanism, Model, and Application”, JSS Project Technical Report 87-02, Swedish Nuclear Fuel and Waste Management Co. (1987).
W.L. Ebert, Phys. Chem. Glasses, 34, 58–65, (1993).
X. Feng and I.L. Pegg, “Effects of Glass Surface Area to Volume Ratio (S/V) on Leachate pH”, J. Non-Cryst. Solids, Accepted, 1993.
X. Feng and I.L. Pegg, “A Glass Dissolution Model for the Effects of S/V on pH”, Ceramic Transactions, Nuclear Waste Management VI, American Ceramics Society, in Press.
R.M. Wallace and G.G. Wicks, in Scientific Basis for Nuclear Waste Management VI, Ed. D.G. Brookins, (North-Holland, NY, 1983), p. 23.
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**ng, SB., Muller, I.S. & Pegg, I.L. Non-Linearity in Glass Composition Dependence of Dissolution Rates: Effect of Solution pH. MRS Online Proceedings Library 333, 549–556 (1993). https://doi.org/10.1557/PROC-333-549
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DOI: https://doi.org/10.1557/PROC-333-549