Hostname: page-component-7bb8b95d7b-qxsvm Total loading time: 0 Render date: 2024-09-27T01:13:06.572Z Has data issue: false hasContentIssue false
  • English
  • Français

Actinide and Technetium Solubility Limitations in Groundwaters of Crystalline Rocks

Published online by Cambridge University Press:  25 February 2011

B. Allard
B. Allard*
Affiliation:
Department of Nuclear Chemistry, Chalmers University of Technology, S-412 96 Göteborg, Sweden.
Get access

Abstract

The solubility and speciation of U, Np, Pu, Am and Tc in deep groundwaters from crystalline rocks have been calculated. The solution chemistry of these elements is largely determined by the redox conditions (Eh = 0.24 − 0.06pH ± 0.06 V, based on measurements of Fe(II)), pH (usually 7 − 9) and the presence of carbonate (log [CO32-] from (pH − 14) to (0.76pH − 10.83), based on measurements of HCO3-). The oxidation states U(IV)(+VI), Np(IV), Pu(III)(+IV), Am(III) and Tc(IV) dominate, with the tetravalent oxides (U, Np, Pu, Tc) and Am2 (CO3)3 (s) as solubility limiting phases. Maximum concentrations in the range 10-9 − 10-10 M or below would be expected for U, Np and Tc under reducing conditions, somewhat higher for Pu and still higher (10-6 − 10-7 M) for Am.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 26: Symposium D – Scientific Basis for Nuclear Waste Management VII , 1983 , 219
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. Allard, B. in: Actinides in Perspective, Edelstein, N., ed. (Pergamon Press, Oxford 1982) pp. 553–580.CrossRefGoogle Scholar
2. Allard, B., Actinide Solution Equilibria and Solubilities in Geologic Systems, SKBF KBS TR 83-35 (Svensk Kärnbränsleförsörjning AB, Stockholm 1983).Google Scholar
3. Allard, B., and Torstenfelt, B., On the Solubility of Technetium in Geochemical Systems, SKBF KBS TR 83-60 (Svensk Kärnbränsleförsörjning AB, Stockholm 1983).Google Scholar
4. Allard, B., Olofsson, U., and Torstenfelt, B., Environmental Actinide Chemistry, Proc. 1st Int. Conf. on the Chem. and Techn. of the Lanthanides and Actinides, Venice, in press (1983).CrossRefGoogle Scholar
5. Allard, B., Larson, S.Å., Tullborg, E.-L., and Wikberg, P., Chemistry of Deep Groundwaters from Granitic Bedrock, SKBF KBS TR 83-59 (Svensk Kärnbränsleförsörjning AB, Stockholm 1983).Google Scholar
6. Ahrland, S., Liljenzin, J.O., and Rydberg, J. in: Comprehensive Inorganic Chemistry. Vol. 5. (Pergamon Press, Oxford 1973) pp. 465–635.CrossRefGoogle Scholar
7. Fuger, J., and Oetting, F.L., The Chemical Thermodynamics of Actinide Elements and Compounds. Part 2. The Actinide Aqueous Ions (IAEA, Vienna 1976).Google Scholar
8. Maya, L., Detection of Hydroxo and Carbonato Species of Dioxouranium(VI) in Aqueous Media by Differential Pulse Polangraphy, Inorg. Chim. Acta, in press (1983).CrossRefGoogle Scholar
9. Paquette, J., and Lemire, R.J., Nucl. Sci. Eng. 9, 26–48 (1981).CrossRefGoogle Scholar
10. Osmond, J.K., and Cowart, J.B., Atomic Energy Rev. 14, 621–679 (1976).Google Scholar
11. Wikberg, P., Grenthe, I., and Axelsen, K., Redox Conditions in Groundwaters from Svartboberget, Gideå, Fjällveden and Kamlunge, SKBF KBS TR 83-40 (Svensk Kärnbränsleförsörjning AB, Stockholm 1983).Google Scholar