Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-29T07:46:38.688Z Has data issue: false hasContentIssue false

Oxidation of UO2 Fuel by Radicals Formed During Radiolysis of Water

Published online by Cambridge University Press:  21 February 2011

S. Sunder
Affiliation:
Geochemistry and Waste Immobilization Division, Atomic Energy of Canada Ltd. Whiteshell Nuclear Research Establishment, Pinawa, Manitoba, CanadaROE 1L0
D.W. Shoesmith
Affiliation:
Geochemistry and Waste Immobilization Division, Atomic Energy of Canada Ltd. Whiteshell Nuclear Research Establishment, Pinawa, Manitoba, CanadaROE 1L0
H. Christensen
Affiliation:
Studsvik, S-611 82 Nykoping, Sweden
N.H. Miller
Affiliation:
Geochemistry and Waste Immobilization Division, Atomic Energy of Canada Ltd. Whiteshell Nuclear Research Establishment, Pinawa, Manitoba, CanadaROE 1L0
M.G. Bailey
Affiliation:
Geochemistry and Waste Immobilization Division, Atomic Energy of Canada Ltd. Whiteshell Nuclear Research Establishment, Pinawa, Manitoba, CanadaROE 1L0
Get access

Abstract

The effects of radicals, formed during radiolysis of water, on the oxidation and dissolution of U02 were investigated as a function of dose rate and total dose. The U02 oxidation rate during radiolysis was monitored by recording the corrosion potential of a U02 electrode as a function of time. Changes in the surface of U02 were determined using cathodic stripping voltammetry (CSV) and X-ray photoelectron spectroscopy (XPS). Our studies suggest that the oxidation of U02, in irradiated de-oxygenated solutions consists of two stages. The first stage consists of the growth of a surface film of composition close to U02.33 and of thickness similar to that obtained (over longer exposure periods) in unirradiated oxygenated solutions. The rate of growth of this film appears to be proportional to the square root of the dose rate. The second stage consists of oxidative dissolution of this film (as U02+2). This step mainly occurs at higher doses. Relative rates of oxidation of U02 to U02.33, the first stage, were obtained in four different solutions favouring the formation of selected radicals.

Type
Research Article
Copyright
Copyright © Materials Research Society 1990

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. Johnson, L.H., and Shoesmith, D.W., “Used Fuel,” in Radioactive waste forms for the future Lutze, W. and Ewing, R.C., ed, Elsevier B.V., pp 635698, (1988).Google Scholar
2. Shoesmith, D.W., Sunder, S., Ikeda, B.M. and King, F., “The Development of a Mechanistic Basis for Modelling Fuel Dissolution and Container Failure Under Waste Vault Conditions” in Scientific Basis for Nuclear Waste Management XII, Lutze, W. and Ewing, R.C. (eds.), Mat. Res. Soc. Symp. Proc. 127, 279291 (1989).Google Scholar
3. Werme, L.O. and Forsyth, R.S., “Spent UO2 Fuel Corrosion in Water; Release Mechanisms”, in Scientific Basis for Nuclear Waste Management XI, Apted, M.J. and Westerman, R.E. (eds.), Mat. Res. Soc. Symp. Proc. 112, 443452 (1987).Google Scholar
4. Lemire, R.J., “Effects of High Ionic Strength Groundwaters on Calculated Equilibrium Concentrations in the Uranium-Water System,” Atomic Energy of Canada Limited Report, AECL-9549, (1988).Google Scholar
5. Sunder, S., Shoesmith, D.W., Johnson, L.H., Bailey, M.G., Wallace, G.J., and Snaglewski, A. P., “Oxidation of CANDUTm Fuel by the Products of Alpha-Radiolysis of Groundwater,” in Scientific Basis for Nuclear Waste Management X, Bates, J.K. and Seefeldt, W.B. (eds.), Mat. Res. Soc. Symp. Proc. 84, 103113 (1987).Google Scholar
6. Shoesmith, D.W., Sunder, S., Johnson, L.H. and Bailey, M.G., “Oxidation of CANDU U02 Fuel by the Alpha-RadiolysisProducts of Water”, Scientific Basis for Nuclear Waste Management IX, Werme, L.O. (ed.), Mat. Res. Soc. Symp. Proc. 50, 309316 (1985).Google Scholar
7. Christensen, H. and Bjergbakke, E., in Scientific Basis for Nuclear Waste Management X, Bates, J.K. and Seefeldt, W.B. (eds.), Mat. Res. Soc. Symp. Proc. 84, 115122 (1987).Google Scholar
8. Sunder, S., Shoesmith, D. W., Christensen, H., Bailey, M. G. and Miller, N., “Electrochemical and X-ray Photoelectron Spectroscopic Studies of U02 Fuel Oxidation by Specific Radicals Formed During Radiolysis of Groundwater”, in Scientific Basis for Nuclear Waste Management XII, Lutze, W. and Ewing, R.C. (eds.), Mat. Res. Soc. Symp. Proc. 127, 317324 (1989).Google Scholar
9. Smith, H.J., Tait, J.C. and Massow, R.E. von, “Radioactive Decay Properties of Bruce “A” CANDUTm U02 Fuel and Fuel Recycle Waste,” Atomic Energy of Canada Limited Report, AECL-9072 (1987).Google Scholar
10. Lundgren, K., “Radiation Levels and Absorbed Doses Around Copper Canisters Containing Spent LWR Fuel,” KBS-TR 82–11.Google Scholar
11. Ikeda, B.M., in the Corrosion Performance of Nuclear Fuel Waste Containers, Nuttall, K. and McKay, P. (eds.), Atomic Energy of Canada Limited Technical Record, TR-340, pp. 8795 (1986).Google Scholar
12. Sunder, S., Shoesmith, D.W., Bailey, M.G., Stanchell, F.W. and McIntyre, N.S., J. Electroanal. Chem. 130, 163179, 1981.Google Scholar
13. Shoesmith, D.W., Sunder, S., Bailey, M.G., and Wallace, G.J., Corrosion Science, 29, 1115 (1988).Google Scholar
14. Sunder, S. and Shoesmith, D.W. (Unpublished work).Google Scholar
15. Shoesmith, D.W., Sunder, S., Bailey, M.G., Wallace, G.J. and Stanchell, F.W., Applic. Surf. Sci. 20, 3957, 1984.Google Scholar
16. Shoesmith, D.W., Sunder, S., Bailey, M.G., and Wallace, G.J., Can. J. Chem. 66, 259265 (1988).Google Scholar