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From Laboratory Experiments to a Geological Disposal Vault: Calculation of Used Nuclear Fuel Dissolution Rates

Published online by Cambridge University Press:  10 February 2011

S. Sunder ,
D.W. Shoesmith ,
M. Kolar  and
D.M. Leneveu
S. Sunder
Affiliation:
Chalk River Laboratories, Chalk River, ON, KOJ IJO
D.W. Shoesmith
Affiliation:
Whiteshell Laboratories, Pinawa, MB, Canada ROE ILO
M. Kolar
Affiliation:
Whiteshell Laboratories, Pinawa, MB, Canada ROE ILO
D.M. Leneveu
Affiliation:
Whiteshell Laboratories, Pinawa, MB, Canada ROE ILO
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Abstract

Calculation of used nuclear fuel dissolution rates in a geological disposal vault requires a knowledge of the redox conditions in the vault. For redox conditions less oxidizing than those causing UO2 oxidation to the U3O7 stage, a thermodynamically-based model is appropriate. For more oxidizing redox conditions a kinetic or an electrochemical model is needed to calculate these rates. The redox conditions in a disposal vault will be affected by the radiolysis of groundwater by the ionizing radiation associated with the fuel. Therefore, we have calculated the alpha-, beta- and gamma-dose rates in water in contact with the reference used fuel in the Canadian Nuclear Fuel Waste Management Program (CNFWMP) as a function of cooling time. Also, we have determined dissolution rates of UO2 fuel as a function of alpha and gamma dose rates from our electrochemical measurements. These room-temperature rates are used to calculate the dissolution rates of used fuel at 100°C, the highest temperature expected in a container in the CNFWMP, as a function of time since emplacement. It is shown that beta radiolysis of water will be the main cause of oxidation of used CANDU fuel in a failed container. The use of a kinetic or an electrochemical corrosion model, to calculate fuel dissolution rates, is required for a period of ∼ 1000 a following emplacement of copper containers in the geologic disposal vault envisaged in the CNFWMP. Beyond this time period a thermodynamically-based model adequately predicts the fuel dissolution rates. The results presented in this paper can be adopted to calculate used fuel dissolution rates for other used UO2 fuels in other waste management programs.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 506: Symposium – Scientific Basis for Nuclear Waste Management XXI , 1997 , 273
Copyright
Copyright © Materials Research Society 1998

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References

REFERENCES

1 Sunder, S. and Shoesmith, D.W., Chemistry of UO2 Fuel Dissolution in Relation to the Disposal of Used Nuclear Fuel. Atomic Energy of Canada Limited Report, AECL-10395. (1991).Google Scholar
2 Shoesmith, D.W. and S. Sunder, An electrochemistry-based model for the dissolution of UO2. Atomic Energy of Canada Limited Report, AECL-10488 (1991).Google Scholar
3 Forsyth, R.S. and Werme, L.O., J. Nucl. Mater. 190, 3 (1992).Google Scholar
4 Gray, W.J., Leider, H.R. and Steward, S.A., J. Nucl. Mater. 190, 46 (1992).Google Scholar
5 Shoesmith, D.W. and Sunder, S., J. Nucl. Mater. 190, 20 (1992).Google Scholar
6 Sunder, S., Shoesmith, D.W., Christensen, H. and Miller, N.H., J. Nucl. Mater. 190, 78 (1992).Google Scholar
7 Sunder, S., Shoesmith, D.W., Miller, N.H. and Wallace, G.J., Mater. Res. Soc. Symp.Proc. 257 345 (1992).Google Scholar
8 Christensen, H., Sunder, S. and Shoesmith, D.W., J. Alloys and Compounds. 213/214, 93 (1994).Google Scholar
9 Johnson, L.H., LeNeveu, D.M., Shoesmith, D.W., Oscarson, D.W., Gray, M.N., Lemire, R.J. and Garisto, N.C., The Disposal of Canada's Nuclear Fuel Waste: The Vault Model for Postclosure Assessment. Atomic Energy of Canada Limited Report, AECL- 10714, COG-93-4 (1994).Google Scholar
10 Grambow, B., Loida, A., Dressler, P., Geckeis, H., Diaz, P., Gago, J., Casas, I., Pablo, J. de, Gimenez, J. and Torrero, M.E., Long-term Safety of Radioactive Waste Disposal: Chemical Reaction of Fabricated and High Burnup Spent UO2Fuel With Saline Brines. Kernforschungszentrum Karlsruhe Report, KfK 5702 (1996).Google Scholar
11 Johnson, L.H., Leneveu, D.M., King, F., Shoesmith, D.W., Kolar, M., Oscarson, D.W., Sunder, S., Onofrei, C. and Crosthwaite, J.L., The Disposal of Canada's Nuclear Fuel Waste: A Study of Post-closure Safety of In-room Emplacement of Used CANDU Fuel in Copper Containers in Permeable Plutonic Rock. Volume 2: Vault model. Atomic Energy of Canada Limited Report, AECL- 111494-2, COG-95-552-2 (1996).Google Scholar
12 Shoesmith, D.W., Sunder, S. and Hocking, W.H., in Electrochemistry of Novel Materials, edited by Lipkowski, J. and Ross, P.N. (VCH Publishers Inc., New York, 1994) p.297.Google Scholar
13 Christensen, H. and Sunder, S.. J. Nucl. Mater., 238, 70 (1996.).Google Scholar
14 Sunder, S., Alpha, Beta and Gamma Dose Rates in Water in Contact with Used CANDU UO2 Fuel. Atomic Energy of Canada Limited Report, AECL- 11380, COG-95-340 (1995).Google Scholar
15 Shoesmith, D.W., Sunder, S., Bailey, M.G. and Wallace, G.J., Corros. Sci. 29, 1115 (1989).Google Scholar
16 Sunder, S., Strandlund, L.K. and Shoesmith, D.W., Anodic Dissolution of UO2 in Slightly Alkaline Sodium Perchlorate Solutions. Atomic Energy of Canada Limited Report, AECL- 11440, COG-95-461 (1996).Google Scholar
17 Shoesmith, D.W., S. Sunder and Tait, J.C., Validation of the Oxidative Dissolution Model for Used CANDU Fuel. Atomic Energy of Canada Limited Report, AECL- 11798, COG-97-0151-1 (1997).Google Scholar
18 Sunder, S., Shoesmith, D.W. and Miller, N.H., J. Nucl. Mater. 244, 66–74 (1997).Google Scholar
19 Smith, H.J., Tait, J.C. and Massow, R.E. von, Radioactive Decay Properties of Bruce “A” CANDUrrM U02 Fuel and Fuel Recycle Waste, Atomic Energy of Canada Limited Report, AECL-9072 (1987).Google Scholar