Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-05T15:43:14.228Z Has data issue: false hasContentIssue false
  • English
  • Français

Modelling experimental results on radiolytic processes at the spent fuel water interface. II. Radionuclides release

Published online by Cambridge University Press:  21 March 2011

E. Cera ,
M. Grivé ,
J. Bruno  and
T.E. Eriksen
E. Cera
Affiliation:
Enviros Spain SL, Pg. de Rubí 29-31, 08197 Valldoreix, (Spain)
M. Grivé
Affiliation:
Enviros Spain SL, Pg. de Rubí 29-31, 08197 Valldoreix, (Spain)
J. Bruno
Affiliation:
Enviros Spain SL, Pg. de Rubí 29-31, 08197 Valldoreix, (Spain)
T.E. Eriksen
Affiliation:
Dept. Nuclear Chemistry, KTH, 100 44 Stockholm, (Sweden)
Get access

Abstract

Experimental and modelling efforts in the last decade in the frame of nuclear waste management field have been focused on studying the role of the UO2 surfaces in poising the redox state of solid/water systems as well as the radionuclides release behaviour. For this purpose, an experimental programme was developed consisting on dissolution experiments with PWR spent fuel fragments in an anoxic environment and by using different solution compositions.

Some of the collected data has been previously published [1], specifically those data concerning radiolysis products and dissolution of the matrix. The results and the modelling tasks indicated an overall balance of the generated radiolytic species and that uranium dissolution was controlled by the oxidation of the spent fuel matrix in 10mM bicarbonate solutions while in the tests carried out at lower or without carbonate concentrations uranium in the aqueous phase was governed by the precipitation of schoepite.

This paper is the continuation of a series accounting for the data and modelling work related to investigating the release behaviour of minor radionuclides from the spent fuel.

Uranium concentrations as a function of time showed an initial increase until reaching a steady state, indicating a matrix dissolution control. The same behaviour is observed for neptunium, caesium, strontium, technetium and molybdenum indicating a congruent release of these elements with the major component of the fuel matrix. On the other hand, no cler tendency is observed for plutonium data where additional solubility limiting mechanisms may apply.

Kinetic modelling of the trace elements: caesium, strontium, technetium and molybdenum is based on the congruent release of these elements with the major component of the fuel matrix. Rate constants have been determined. Kinetic modelling of neptunium data took also into account the subsequent precipitation as Np(IV) hydroxide. Finally, measured Pu concentrations may be explained by the precipitation of Pu(IV) and/or Pu(III) solid phases.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 932: Symposium – Scientific Basis for Nuclear Waste Management XXIX , 2006 , 65.1
Copyright
Copyright © Materials Research Society 2006

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. Bruno, J., Cera, E., Eriksen, T.E., Grivé, M. and Ripoll, S.. MRS Symposium Proceedings, Vol. 807, 397–402 (2004).Google Scholar
2. Johnson, L.H. and Shoesmith, D.W., 1988, in: Radioactive waste forms for the future, ed. Lutze, and Ewing, (Elsevier), 635–698.Google Scholar
3. Shoesmith, D.W.. J. Nucl. Mater., 282, 1–31 (2000).Google Scholar
4. Gray, W.J. and Wilson, C.N.. Report PNL-10540, USA (1995).Google Scholar
5. Forsyth, R.. SKB TR 97-25 (1997).Google Scholar
6. Bruno, J., Cera, E., Duro, L., Pon, J., J. de Pablo, T. Eriksen. SKB TR 98-22 (1998)Google Scholar
7. Bruno, J., Cera, E., Eklund, U.-B., Eriksen, T., Grivé, M., Spahiu, K.. Radiochim. Acta, 88, Issue 9-11, p.513 (2000)Google Scholar
8. Bruno, J., Cera, E., Grivé, M., Eklund, U-B. and Eriksen, T.E.. SKB TR 99-26 (1999).Google Scholar
9. Kleykamp, H.. Nucl. Techn., 80, 412–422 (1988).Google Scholar
10. Thorstenton, D.C. and Plummer, L.N.. Amer. J. of Sci., 277, 1203–1223 (1977).Google Scholar
11. Bruno, J., Cera, E., Eriksen, T.E., Grivé, M., and Duro, L.. SKB TR 03-03 (2003).Google Scholar
12. Lasaga, A.C., 1981. in: Reviews in mineralogy. Vol. 8. ed. Lasaga, and Kirkpatrick, (Miner. Soc. of Amer.), 1–68.Google Scholar
13. Rard, J.A., Rand, M.H., Anderegg, G. and Wanner, H.., 1999 Chemical Thermodynamics 3. Chemical thermodynamics of Technetium ed. Sandino, A. and Ósthols, E. (NEA OECD, Elsevier).Google Scholar
14. Neck, V., and Kim, J.I.. Radiochim. Acta, 89, 1–16 (2001).Google Scholar
15. Pearson, F.J. Jr., Berner, U. and Hummel, W.. NAGRA Technical Report 91-18 (1992).Google Scholar
16. Lemire, R.J. and Garisto, F.. Atomic Energy of Canada Limited, AECL-10009 (1989).Google Scholar
17. Duro, L., Grivé, M., Domínech, C., Cera, E., Gaona, X., Bruno, J.. ANDRA Report, Version 3, 384pp. (2005).Google Scholar