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RESEARCH ARTICLE

Aluminoborosilicate waste glass dissolution under alkaline conditions at 40°C: implications for a chemical affinity-based rate equation

E. M. Pierce A B , E. L. Richards A , A. M. Davis A , L. R. Reed A and E. A. Rodriguez A
+ Author Affiliations
- Author Affiliations

A Energy and Environment Directorate, Pacific Northwest National Laboratory, PO Box 999, MS: K3-62, Richland, WA 99354, USA.

B Corresponding author. Email: eric.pierce@pnl.gov

Environmental Chemistry 5(1) 73-85 https://doi.org/10.1071/EN07058
Submitted: 4 September 2007  Accepted: 25 January 2008   Published: 22 February 2008

Environmental context. The production of nuclear materials has generated a very large amount of highly radioactive wastes that need to be disposed of in a manner that will keep them from posing a danger for millions of years until the radioactivity decays. The process being considered for this daunting task is to contain the wastes in glass. Although studies with ancient and natural glass suggest the weathering of glass is slow, experiments are being conducted to determine the impact of this material on the natural environment and attempt to predict its long-term behaviour. The present paper briefly discusses three models that are being considered for implementing this process and the one that appears to hold the most promise.

Abstract. Single-pass flow-through experiments were conducted with aluminoborosilicate waste glasses to evaluate how changes in solution composition affect the dissolution rate (r) at 40°C and pH (23°C) = 9.0. The three prototypic low-activity waste (LAW) glasses, LAWE-1A, -95A and -290A, used in these experiments span a wide range covering the expected processing composition of candidate immobilised low-activity waste (ILAW) glasses. Results suggest incongruent release of Al, B, Na, and Si at low flow-rate (q) to sample surface area (S), in units of (m s–1), (log10(q/S) < –8.9) whereas congruent release is observed at high q/S (log10(q/S) > –7.9). Dissolution rates increase from log10(q/S) ≈ –9.3 to –8.0 and then become constant at log10(q/S) > –7.9. Forward (maximum) dissolution rates, based on B release, are the same irrespective of glass composition, evident by the dissolution rates being within the experimental error of one another (r1A = 0.0301 ± 0.0153 g m–2 day–1, r95A = 0.0248 ± 0.0125 g m–2 day–1, and r290A = 0.0389 ± 0.0197 g m–2 day–1). The results also illustrate that as the activity of SiO2(aq) increases, the rate of glass dissolution decreases to a residual rate. The pseudo-equilibrium constant, Kg, (log10(Kg) = –3.7) predicted with these results is slightly lower than the K for chalcedony (log10(K) = –3.48) at 40°C. Finally, these results support the use of a chemical affinity-based rate law to describe glass dissolution as a function of solution composition.

Additional keywords: boron coordination, forward rate, free energy of hydration, low-activity waste glass, Transition State Theory.


Acknowledgements

The authors would like to acknowledge F. M. Mann at CH2M HILL Hanford Group, Inc. (Richland, WA) for providing project funding. The authors would also like to express gratitude to S. R. Baum, of Pacific Northwest National Laboratory (PNNL), for providing high-quality analytical data from sample solutions. We would also like to acknowledge the student funding obtained from the Department of Energy’s (DOE) Community College Initiative Program (L. R. Reed) and the Science and Engineering Education Internship Program (A. M. Davis) being administered at PNNL. A portion of the present research was performed in part with the nuclear magnetic resonance spectrometers in the William R. Wiley Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by DOE’s Office of Biological and Environmental Research and located at PNNL (proposal #14592). PNNL is operated by Battelle for DOE under Contract DE-AC05–76RL01830.


References


[1]   H. Eyring , The activated complex in chemical reactions. J. Chem. Phys. 1935 , 3,  107.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[2]   P. Åagaard , H. C. Helgeson , Thermodynamic and kinetic constraints on reaction rates among minerals and aqueous solutions. I. Theoretical considerations. Am. J. Sci. 1982 , 282,  237.
         open url image1

[3]   B. Grambow , A general rate equation for nuclear waste glass corrosion. Material Research Symposium Proceedings 1985 , 44,  15.
         open url image1

[4]   S. Gin , P. Jollivet , J. P. Mestre , M. Jullien , C. Pozo , French SON 68 nuclear glass alteration mechanisms on contact with clay media. Appl. Geochem. 2001 , 16,  861.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[5]   C. Jegou , S. Gin , F. Larche , Alteration kinetics of a simplified nuclear glass in an aqueous medium: effects of solution chemistry and of protective gel properties on diminishing the alteration rate. J. Nuc. Mater. 2000 , 280,  216.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[6]   R. H. Doremus , Y. Mehrotra , W. A. Lanford , C. Burman , Reaction of water with glass: influence of a transformed surface layer. J. Mater. Sci. 1983 , 18,  612.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[7]   McGrail B. P., Lindenmeier C. W., Martin P. F., Gee G. W., The Pressurized Unsaturated Flow (PUF) Test: a new method for engineered-barrier materials evaluation, in Environmental Issues and Waste Management Technologies in the Ceramic and Nuclear Industries II (Eds V. Jain, D. K. Peeler) 1996, Vol. 72, pp. 317–329 (The American Ceramic Society: Westerville, OH).

[8]   McGrail B. P., Martin P. F., Lindenmeier C. W., Schaef H. T., Application of the pressurized unsaturated flow (PUF) test for accelerated ageing of waste forms, in Proceedings of the International Conference on Ageing Studies & Lifetime Extension of Materials (Ed. L. M. Mallinson) 1999, pp. 313–321 (Kluwer Academic and Plenum Publishers: New York).

[9]   E. M. Pierce , B. P. McGrail , M. M. Valenta , D. M. Strachan , The accelerated weathering of a radioactive low-activity waste glass under hydraulically unsaturated conditions: experimental results from a Pressurized Unsaturated Flow (PUF) test. Nucl. Technol. 2006 , 155,  133.
         open url image1

[10]   E. M. Pierce , B. P. McGrail , J. Marra , P. F. Martin , B. W. Arey , K. N. Geiszler , Accelerated weathering of a high-level and Pu-bearing lanthanide borosilicate waste glass in a can-in-canister configuration. Appl. Geochem. 2007 , 22,  1841.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[11]   McGrail B. P., Martin P. F., Schaef H. T., Lindenmeier C. W., Owen A. T., in Material Research Symposium Proceedings Scientific Basis for Nuclear Waste Management XXIII, Boston, MS, 29 November–2 December 1999 (Eds R. W. Smith, D. W. Shoesmith) 2000, Vol. 608, pp. 345–352 (Material Research Society: Boston, MS).

[12]   B. Grambow , R. Müller , First-order dissolution rate law and the role of surface layers in glass performance assessment. J. Nuc. Mater. 2001 , 298,  112.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[13]   Grambow B., Nuclear waste glasses – how durable? in Elements: an International Magazine of Mineralogy, Geochemistry, and Petrology 2007, Vol. 2 (Mineralogical Society of America, Mineralogical Society of Great Britain and Ireland, Mineralogical Association of Canada, Geochemical Society, The Clay Minerals Society, European Association for Geochemistry, International Association of GeoChemistry, and Société Française de Minéralogie et de Cristallographie: Richmond Hill, ON).

[14]   E. Vernaz , S. Gin , C. Jegou , I. Ribet , Present understanding of R7T7 glass alteration kinetics and their impact on long-term behavior modeling. J. Nuc. Mater. 2001 , 298,  27.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[15]   P. K. Abraitis , F. R. Livens , J. E. Monteith , J. S. Small , D. P. Trivedi , D. J. Vaughan , R. A. Wogelius , The kinetics and mechanisms of simulated British Magnox waste glass dissolution as a function of pH, silicic acid activity, and time in low-temperature aqueous systems. Appl. Geochem. 2000 , 15,  1399.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[16]   C. M. Jantzen , M. J. Plodinec , Thermodynamic model of natural medieval, and nuclear waste glass durability. J. Non-Cryst. Solids 1984 , 67,  207.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[17]   Plodinec M. J., Jantzen C. M., Wicks G. G., Stability of radioactive waste glasses assessed from hydration thermodynamics, in Scientific Basis for Nuclear Waste Management VII (Ed. G. L. McVay) 1984, Vol. 26 (Elsevier Science: Boston, MA).

[18]   A. Paul , Chemical durability of glasses; a thermodynamic approach. J. Mater. Sci. 1977 , 12,  2246.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[19]   Lasaga A. C., Fundamental approaches in describing mineral dissolution and precipitation rates, in Chemical Weathering Rates of Silicate Minerals (Eds A. F. White, S. L. Brantley) 1995, Vol. 31, pp. 23–86 (Mineralogical Society of America: Washington, DC).

[20]   Pierce E. M., McGrail B. P., Icenhower J. P., Rodriguez E. A., Steele J. L., Baum S. R., in American Chemical Society Division of Environmental Chemistry 2004, Vol. 44, pp. 1151–1158 (American Chemical Society: Philadelphia, PA).

[21]   Pierce E. M., McGrail B. P., Rodriguez E. A., Schaef H. T., Saripalli K. P., Serne R. J., Krupka K. M., Martin P. F., Baum S. R., Geiszler K. N., Reed L. R., Shaw W. J., Waste Form Release Data Package for the 2005 Integrated Disposal Facility Performance Assessment, PNNL-14805 2004 (Pacific Northwest National Laboratory: Richland, WA).

[22]   Bourcier W. L., Peiffer D. W., Knauss K. G., McKeegan K. D., Smith D. K., in Scientific Basis for Nuclear Waste Management 1990, Vol. 176, p. 209 (Materials Research Society: Boston, MS).

[23]   Advocat T., Crovisier J. L., Fritz B., Vernaz E., in Scientific Basis for Nuclear Waste Management 1990, Vol. 176, p. 241 (Materials Research Society: Boston, MS).

[24]   Wolery T. J., EQ3NR, A Computer Program for Geochemical Aqueous Speciation-Solubility Calculations: Theoretical Manual, User's Guide, and Related Documentation (Version 7.0), UCRL-MA-110662 PT III 1992 (Lawrence Livermore National Laboratory: Livermore, CA).

[25]   B. P. McGrail , J. P. Icenhower , D. K. Shuh , P. Liu , J. G. Darab , D. R. Baer , S. Thevuthasan , V. Shutthanandan , M. H. Engelhard , C. H. Booth , P. Nachimuthu , The structure of Na2O–Al2O3–SiO2 glass: impact on sodium ion exchange in H2O and D2O. J. Non-Cryst. Solids 2001 , 296,  10.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[26]   Casey W. H., Bunker B. C., Leaching of mineral and glass surfaces during dissolution, in Mineral–Water Interface Geochemistry (Eds M. F. Hochella, Jr, A. F. White) 1990, Vol. 23, pp. 397–426 (Mineralogical Society of America: Washington, DC).

[27]   D. Perret , J. L. Crovisier , P. Stille , G. Shields , Thermodynamic stability of waste glasses compared to leaching behaviour. Appl. Geochem. 2003 , 18,  1165.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[28]   Y. Linard , T. Advocat , C. Jegou , P. Richet , Thermochemistry of nuclear waste glasses: application to weathering studies. J. Non-Cryst. Solids 2001 , 289,  135.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[29]   R. Conradt , A proposition for an improved theoretical treatment of the corrosion of multi-component glasses. J. Nuc. Mater. 2001 , 298,  19.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[30]   Jantzen C. M., Pickett J. B., Brown G., Edwards T. B., Method of Determining Glass Durability, Westinghouse Savannah River Company, United States of America, Patent #5846278 1998.

[31]   C. M. Jantzen , I. Nuclear waste glass durability, predicting environmental response from thermodynamic (Pourbaix) diagrams. J. Am. Ceram. Soc. 1992 , 75,  2433.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[32]   J. P. Icenhower , B. P. McGrail , W. J. Shaw , E. M. Pierce , P. Nachimuthu , D. K. Shuh , E. A. Rodriguez , J. L. Steele , Experimentally determined dissolution kinetics of Na-rich borosilicate glasses at far-from-equilibrium conditions: implications for transition state theory. Geochim. Cosmochim. Acta in press.
         open url image1

[33]   E. H. Oelkers , S. R. Gislason , The mechanism rates, and consequences of basaltic glass dissolution: I. An experimental study of the dissolution rates of basaltic glass as a function of aqueous Al, Si, and oxalic acid concentration at 25°C and pH = 3 and 11. Geochim. Cosmochim. Acta 2001 , 65,  3671.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[34]   E. H. Oelkers , General kinetic description of multioxide silicate mineral and glass dissolution. Geochim. Cosmochim. Acta 2001 , 65,  3703.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[35]   Muller I. S., Diener G., Joseph I., Pegg I. L., Proposed Approach for Development of LAW Glass Formulation Correlation. Letter Report, VSL-04L4460-1 2004 (Vitreous State Laboratory, The Catholic University of America for Durateck Inc. and Bechtel National Inc.: Washington, DC).

[36]   Deng Y., Supplemental LAW Plant Flowsheet Run Results, 24590-WTP-MRR-PO-04-0011, Rev.0 2004 (Bechtel National Inc.: Richland, WA).

[37]   Vienna J. D., Preliminary ILAW Formulation Algorithm Description, 24590-LAW-RPT-RT-04-0003, Rev 0 2005 (Bechtel National Inc.: Richland, WA).

[38]   ASTM, Standard Test Methods for Sieve Analysis of Fine and Coarse Aggregates, ASTM C136 2001 (American Society for Testing and Materials International: Philadelphia, PA).

[39]   McGrail B. P., Olson K. M., Evaluating Long-Term Performance of In Situ Vitrified Waste Forms: Methodology and Results, PNL-8358, UC-602 1992 (Pacific Northwest Laboratory: Richland, WA).

[40]   B. P. McGrail , W. L. Ebert , A. J. Bakel , D. K. Peeler , Measurement of kinetic rate law parameters on a Na-Ca-Al borosilicate glass for low-activity waste. J. Nuc. Mater. 1997 , 249,  175.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[41]   S. Brunauer , P. H. Emmett , E. Teller , Adsorption of gases in multimolecular layers. J. Am. Chem. Soc. 1938 , 60,  309.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[42]   McGrail B. P., Icenhower J. P., Martin P. F., Rector D. R., Schaef H. T., Rodriguez E. A., Steele J. L., Low-Activity Waste Glass Studies: FY2000 Summary Report, PNNL-13381 2000 (Pacific Northwest National Laboratory: Richland, WA).

[43]   D. Wolff-Boenisch , S. R. Gislason , E. H. Oelkers , C. Putnis , The dissolution rates of natural glasses as a function of their composition at pH 4 and 10.6, and temperatures from 25 to 74°C. Geochim. Cosmochim. Acta 2004 , 68,  4843.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[44]   C. Papelis , W. Um , C. E. Russell , J. B. Chapman , Measuring the specific surface area of natural and manmade glasses: effects of formation process, morphology, and particle size. Colloid. Surface. A 2003 , 215,  221.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[45]   E. M. Pierce , J. P. Icenhower , R. J. Serne , J. Catalano , Experimental determination of UO2(cr) dissolution kinetics: effects of solution saturation state and pH. J. Nuc. Mater. 2005 , 345,  206.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[46]   J. P. Icenhower , D. M. Strachan , B. P. McGrail , R. D. Scheele , E. A. Rodriguez , J. L. Steele , V. L. Legore , Dissolution kinetics of pyrochlore ceramics for the disposition of plutonium. Am. Mineral. 2006 , 91,  39.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[47]   D. M. Wellman , J. P. Icenhower , A. P. Gamerdinger , S. W. Forrester , Effects of pH, temperature, and aqueous organic material on the dissolution kinetics of meta-autunite minerals, (Na,Ca)2–1[(UO2)(PO4)]2·3H2O. Am. Mineral. 2006 , 91,  143.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[48]   E. M. Pierce , D. M. Wellman , A. M. Lodge , E. A. Rodriguez , Experimental determination of the dissolution kinetics of zero-valent iron in the presence of organic complexants. Environ. Chem. 2007 , 4,  260.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1