Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-25T19:40:04.218Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects of Water Chemistry on the Leach Resistance of Synroc C

Published online by Cambridge University Press:  25 February 2011

J. L. Woolfrey  and
D. M. Levins
J. L. Woolfrey
Affiliation:
Australian Atomic Energy Commission, Research Establishment, Lucas Heights Research Laboratories, Sydney, Australia
D. M. Levins
Affiliation:
Australian Atomic Energy Commission, Research Establishment, Lucas Heights Research Laboratories, Sydney, Australia
Get access

Abstract

The chemical durability of SYNROC C has been measured as a function of repository conditions, namely, temperature, surface/volume ratio, groundwater pH and composition. The leach rate of SYNROC C is less dependent on temperature than borosilicate glasses; activation energies range from 15-25 kJ mol-1 compared to 33-74 kJ mol-1 for glass. The rate of release from SYNROC C is very low and independent of solution composition for the solutions studied. There is little variation in leach rate over the pH range 4-9, but at pH 2 the rate is up to 10 times higher. SYNROC C leach rate is independent of flow rate or surface/volume ratio for the mobile waste elements because of the unimportance of solution saturation effects owing to the low concentration of dissolved solids. The differential leach rate decreases rapidly with time because, after initial leaching from grain boundaries and metastable minor phases, the highly insoluble matrix protects the more leachable elements from further attack.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 26: Symposium D – Scientific Basis for Nuclear Waste Management VII , 1983 , 663
Copyright
Copyright © Materials Research Society 1984

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. Ringwood, A.E., Oversby, V.M., Kesson, S.E., Sinclair, W., Ware, N., Hibberson, W., Major, A., Nucl. Chem. Waste Manage., 2 287 (1981).Google Scholar
2. Ringwood, A.E. and Kesson, S.E., “Incorporation of High-level Nuclear Wastes in Revised SYNROC C formulations”, manuscript in preparation.Google Scholar
3. Kesson, S.E., “The Immobilization of Cesium in SYNROC Hollandite”. Submitted to Radioact. Waste Manage., (1983).Google Scholar
4. Dosch, R.G. and Lynch, Q.E., “Solution Chemistry in SYNROC Preparation”, SAND 80-2375 (1980).Google Scholar
5. Reeve, K.D., Levins, D.M., Ramm, E.J., and Woolfrey., J.L. Proc. IAEA/CEC/NEA Symp. on Conditioning of Radioactive Wastes for Storage and Disposal, Utrecht, Neth., (1982).Google Scholar
6. Johnston, J.W. and Daniel, J.L., “Summary Report for the Interlaboratory Round Robin on the MCC-l Static Leach Test Method”, PNL-4249 (1982).Google Scholar
7. Cooper, J., Cousens, D.R., Myhra, S., Segall, R.L., Smart, R. St. C., Turner, P.S. and White, T.J., “Grain Boundary Sinks for HLW Species and Caesium Mobility in SYNROC”, in preparation for submission to J. Mater. Sci. Google Scholar
8. Solomah, A.G. and Zumwalt, L.R., Nucl. Chem. Waste Manage., 3 111 (1982).Google Scholar
9. Reeve, K.D., Levins, D.M., Ramm, E.J., Woolfrey, J.L., Buykx, W.J., Ryan, R.K. and Chapman., J.F. Proc. Waste Management '81, Tucson, Arizona, Vol 1, pp 249–266.Google Scholar
10. Strachan, D.M., Mater. Res. Soc. Symp. Proc., 11 181 (1982).Google Scholar
11. Westsik, J.H. and Turcotte, R.P., “Hydrothermal Reactions of Nuclear Waste Solids: A Preliminary Study”, PNL-2759 Richland, WA (1978).Google Scholar
12. Chick, L.A. and Turcotte, R.P., “Glass Leaching Performance”, PNL-4576 (1983).Google Scholar
13. Materials Characterization Center. “Nuclear Waste Materials Handbook – Waste Form Test Methods”, DOE/TIC-11400 (1981).Google Scholar
14. Weast, R.C. (Ed.), Handbook of Chemistry and Physics (CRC Press Inc., Cleveland, Ohio 1977).Google Scholar
15. Burns, W.G., Hughes, A.E., Marples, J.A.C., Nelson, R.S. and Stoneham, A.M., J. Nucl. Mater., 107 245 (1982).Google Scholar
16. Barkatt, A., Barkatt, A. and Sousanpour, W., Nature, 21 339 (1983).Google Scholar
17. Pederson, L.R., Buckwalter, C.Q., McVay, G.L. and Riddle, B.L., Mater. Res. Soc. Symp. Proc., 15 47 (1983).Google Scholar
18. Strachan, D.M., Barnes, B.O. and Turcotte, R.P., “Standard Leach Tests for Nuclear Waste Materials”, PNL-SA-8712; also Mater. Res. Soc. Symp. Proc., 3 347 (1980).Google Scholar