Hostname: page-component-76fb5796d-45l2p Total loading time: 0 Render date: 2024-04-25T10:26:47.019Z Has data issue: false hasContentIssue false

Optimization of immobilization of strontium and uranium by the solid matrix

Published online by Cambridge University Press:  10 February 2011

S. Raicevic
Affiliation:
VINCA Institute of Nuclear Sciences P.O. Box 522, 11001 Belgrade, Yugoslaviaraich@beotel.nu
I. Plecas
Affiliation:
VINCA Institute of Nuclear Sciences P.O. Box 522, 11001 Belgrade, Yugoslaviaraich@beotel.nu
D. I. Lalovic
Affiliation:
VINCA Institute of Nuclear Sciences P.O. Box 522, 11001 Belgrade, Yugoslaviaraich@beotel.nu
V. Veljkovic
Affiliation:
VINCA Institute of Nuclear Sciences P.O. Box 522, 11001 Belgrade, Yugoslaviaraich@beotel.nu
Get access

Abstract

One of the basic physical parameters which defines: (1) the capacity of the solid matrix for the incorporation (sorption) of the impurity and (2) the stability of the solid matrix -impurity system, is the ion-ion interaction potential, representing the main term of the cohesive energy. Using this parameter determined in the frame of the pseudopotential theory and pseudoatomic approximation we have investigated the systems HAP-Sr and HAP-UO2. In analysis, the hydroxyapatite (HAP, Ca10(PO4)6(OH)2) was selected as a model solid matrix since insoluble phosphates, phosphate ceramic and apatite-like materials are candidates for the immobilization of radionuclides. The substitution of calcium atoms by different impurities in HAP can be presented by the formula: Ca10-xMx(PO4)6(OH)2, where 0 ≤ x ≤ 10 and M = Sr2+, UO22+. It has been shown that (1) Sr can be safely immobilized by HAP, natural apatites and phosphate rocks in the whole range of its concentrations, and (2) that HAP is not an appropriate solid-matrix for immobilization of UO22+ because its incorporation in the low concentration results in a decrease of the matrix stability, stimulating formation of the inhomogeneous structure containing isolated clusters of the UO2- apatite solid phase.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

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. IAEA Technical Report Series No. 287, Treatment of alpha bearing waste, (IAEA, Vienna, 1988), p. 39.Google Scholar
2. Plecas, I., in Proceedings on the International Conference TOP SAFE'98, (Valencia, 1998) pp. 3436.Google Scholar
3. Roy, R., Radioactive Waste Disposal, (Pergamon Press, New York, 1982).Google Scholar
4. Lutze, W. and Ewing, R.C., Radioactive Waste Forms for the Future, (Elsevier Science Publishers, Amsterdam, 1988).Google Scholar
5. Harrison, W. A., Pseudopotentials in the Theory of Metals, (Benjamin, New York, 1966).Google Scholar
6. Heine, V. and Weaire, D., Pseudopotential theory of cohesion and structure, in Solid State Physics, Vol.24, edited by Ehrenreich, H., Seitz, F. and Tumbll, D. (Academic Press, 1970), p. 427.Google Scholar
7. Narasaraju, T. S. B. and Phebe, D. E., J. Mater. Sci. 31, 1 (1996).Google Scholar
8. Raicevic, S., Vukovic, Z., Lazic, S. and Mandic, M., J. Radioanal. Nucl. Chem. Articles 198, 303 (1995); S. Raicevic, Z. Vukovic, T. L. Lizunova and V. F. Komarov, J. Mater. Sci., 203, 363 (1996).Google Scholar
9. Ma, Q. Y., Traina, S. J., Logan, T. J. and Ryan, J. A., Environ. Sci. Technol. 27, 1803 (1993).Google Scholar
10. Jeanjean, J., Rouchaud, J. C., Tran, L. and Fedoroff, M. J., J. Radioanal. Nucl. Chem. Letters 201, 529 (1995).Google Scholar
11. Gauglitz, R., Mat. Res. Soc. Proc. 257, 567 (1992).Google Scholar
12. Veljkovic, V. and Slavic, I., Phys. Rev. Lett. 29, 105 (1972).Google Scholar
13. Veljkovic, V., Phys. Lett. 45A, 41 (1973).Google Scholar
14. Veljkovic, V. and Lalovic, D. I., Phys. Rev. B 11, 4242 (1975); Phys. Lett. A 142, 528 (1989).Google Scholar
15. Slavica, Raicevic, Lalovic, D. I. and Yu., V. Veljkovic, Patent File No. P269/97 (25 June 1997).Google Scholar
16. Lower, S. K., Maurice, P. A. and Traina, S. J., Geochim. Cosmochim. Acta 62, 1773 (1998).Google Scholar
17. Moncoffre, N., Barbier, G., Leblond, E., Martin, P. and Jaffrezic, H., Nucl. Inst. Meth. Phys. Res. Sec. B 140, 402 (1998).Google Scholar