Hostname: page-component-76fb5796d-vvkck Total loading time: 0 Render date: 2024-04-26T19:01:22.897Z Has data issue: false hasContentIssue false
  • English
  • Français

Electron Microscopy Study of Reaction Sintered HLW Glass

Published online by Cambridge University Press:  11 February 2011

Weiliang Gong  and
Werner Lutze
Weiliang Gong
Affiliation:
Vitreous State Laboratory, The Catholic University of America, Washington, D.C. 20064, USA
Werner Lutze
Affiliation:
Vitreous State Laboratory, The Catholic University of America, Washington, D.C. 20064, USA
Get access

Abstract

Reaction sintering under pressure can be used to vitrify radioactive waste. We used defense waste simulate with high concentrations of refractory oxide ZrO2 (∼36 wt%). Silicate glasses with 30 to 50 wt% of waste loading were prepared by hot isostatic pressing (800 °C, 28 MPa). Amorphous silica (50 to 70 wt%) was added to calcined waste simulants. The reaction sintered final products were characterized by scanning and analytical electron microscopy. Our results showed that a continuous glass phase formed. Waste components such as Na2O, CaO, MnO2, Fe2O3, and Al2O3 dissolved in the glass phase. ZrO2 dissolved as well but reached its solubility limit. Nanometer size crystals of baddeleyite (ZrO2) suggest that their presence is a result of super-saturation of the glass phase rather than incomplete dissolution. The sodium concentration increases in the early stages of reaction sintering and decreases towards the end and so does solubility of ZrO2 and other oxides. The microstructure of reaction sintered glasses is determined by a) the concentrations of refractory oxides, b) the concentration of reaction sintering agents, c) the particle size of glass formers, and d) sintering conditions, e.g., temperature and time. Evidence is provided by respective analytical data and micrographs.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 757: Symposium II – Scientific Basis for Nuclear Waste Management XXVI , 2002 , II5.2
Copyright
Copyright © Materials Research Society 2003

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

REFERENCES

[1] Piepel, G.F., Rao, Q., Hrma, P., and Crum, J.V., J. Non-Cryst. Solids 220, 17 (1997).Google Scholar
[2] Vienna, J.D., Hrma, P., Crum, J.V., and Mika, M., J. Non-Cryst. Solids 292, 1 (2001).Google Scholar
[3] Gahlert, S. and Ondracek, G. (1988) Sintered Glass, in Radioactive Waste Form for the Future, ed. Lutze, W. and Ewing, R.C. (North-Holland, New York), pp. 162–192.Google Scholar
[4] Audero, M.A., Bevilacqua, A.M., de Bernasconi, Norma B.M., J. Nucl. Mater. 223, 151 (1995).Google Scholar
[5] Bevilacqua, A.M., Norma, B.M. Bernasconi, de, Russo, D.O., Audero, M.A., Sterba, M.E., and Heredia, A.D., J. Nucl. Mater. 229, 187 (1996).Google Scholar
[6] Gong, W.L., Lutze, W., Abdelouas, A., and Ewing, R.C., J. Nucl. Mater. 265, 12 (1999).Google Scholar
[7] Gong, W.L., Lutze, W., and Ewing, R.C., J. Nucl. Mater. 278, 73 (2000).Google Scholar
[8] Frischat, G. H. (1975) Ionic Diffusion in Oxide Glasses (Trans. Tech. Publications, Aedermannsdorf, Switzerland).Google Scholar
[9] Kracek, F. C., J. Phys. Chem. 34, 1583 (1930).Google Scholar
[10] Bowen, N. L., Schairer, J. F. and Williams, H. W. V., Am. J. Sci. 5th Ser., 20, 421 (1930).Google Scholar