Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-09T19:51:47.918Z Has data issue: false hasContentIssue false
  • English
  • Français

Disproportionation and Polymerization of Plutonium(IV) in Dilute Aqueous Solutions

Published online by Cambridge University Press:  25 February 2011

T. W. Newton  and
V. L. Rundberg
T. W. Newton
Affiliation:
Los Alamos National Laboratory, P. O. Box 1663, Los Alamos, NM 87545, USA
V. L. Rundberg
Affiliation:
Los Alamos National Laboratory, P. O. Box 1663, Los Alamos, NM 87545, USA
Get access

Abstract

The rates of polymerization and disproportionation of Pu(IV) have been studied using low concentrations: (1.7 − 10) × 10−6M Pu, (0.8 − 12) × 10−4M HCI and 0.01M ionic strength. Osmium(II) complexes such as the tris−4,41−2,21−bipyridine complex were found to react rapidly with Pu(IV) but very slowly, if at all, with Pu(IV) polymer, Pu(lll), or Pu(V). Thus, it is possible to determine unreacted Pu(IV) in the presence of reaction products by using Os(II) complexes. Disproportionation reaction products, Pu(IlI) and Pu(V), were determined using their reactions with Ce(IV) sulfate. We find −d[Pu(IV)]/dt = k'[Pu(IV)]2 at constant pH. Log k1 varies from about 4.25 at pH 3 to about 7.0 at pH 4.1 (units for k1 are M−1min−1). The [H+] dependence varies from about −2 to −3 over the pH range studied. The measured rate is the sum of those for polymerization and disproportionation; the latter reaction amounts to about 75% of the total at pH 3 and 20% at pH 4. The second-order rate constants for disproportionation are very much larger than expected on the basis of extrapolation from 0.2 to 1.OM HClO, solutions. The products of the reaction do not affect the rate, but U(VI), aged Pu(IV) polymer, and CO2 increase the rate.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 26: Symposium D – Scientific Basis for Nuclear Waste Management VII , 1983 , 867
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. Baes, C. F. and Mesmer, R. E., The Hydrolysis of Cations (John Wiley and Sons, New York, 1976), pp. 187.Google Scholar
2. (a) Rabideau, S. W., J. Amer. Chem. Soc. 75, 798–801 (1953).10.1021/ja01100a011CrossRefGoogle Scholar
2a. (b) Rabideau, S. W. et al. , Proc. 2nd UN Int. Conf. on Peaceful Uses of At. Energy, Geneva, 28, 361–372 (1958).Google Scholar
3. Cleveland, J. M., The Chemistry of Plutonium (Gordon and Breach Science Publishers, New York, 1970), pp. 83–89.Google Scholar
4. Bell, J. T., Costanzo, D. A., and Biggers, R. E., J. Inorg. Nucl. Chem. 35, 623–628 (1973).10.1016/0022-1902(73)80576-7CrossRefGoogle Scholar
5. Toth, L. M., Friedman, H. A., and Osborne, M. M., J. Inorg. Nucl. Chem. 43, 2929–2934 (1981).10.1016/0022-1902(81)80645-8CrossRefGoogle Scholar
6. Lloyd, M. H. and Haire, R. G., Radiochim. Acta 25, 139–148 (1978).10.1524/ract.1978.25.34.139CrossRefGoogle Scholar
7. Rai, D. and Swanson, J. L., Nucl. Technol. 54, 107–112 (1981).10.13182/NT81-A32758CrossRefGoogle Scholar
8. Taube, H., Stanford University, suggested use of Os complexes, personal communication.Google Scholar
9. Fabian, R. H., Klassen, D. M., and Sonntag, R. W., Inorg. Chem. 19, 1977 (1980).10.1021/ic50209a029CrossRefGoogle Scholar
10. Buckingham, D. A., Dwyer, F. P., and Sargeson, A. M., “Osmium(III)-Osmium(II) Electrode Potentials,” Inorg. Chem. 5, 1243 (1966).10.1021/ic50041a037CrossRefGoogle Scholar
11. Gehmecker, H., Lerch, M., Heimann, R., Kaffrell, A. K., Lewening, A., Trautmann, N., and Herrmann, G., Institut far Kernchemie der Universität Mainz, Germany, personal communication.Google Scholar
12. Newton, T. W., ERDA Critical Review Series, TID-26506 (1975) p. 68.Google Scholar