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The Effect of Mineral Variability on the Solubility of SomeActinides: an Uncertainty Analysis

Published online by Cambridge University Press:  03 September 2012

Christian Ekberg ,
Allan T. Emrén  and
Anders Samuelsson
Christian Ekberg
Affiliation:
Department of Nuclear Chemistry, Chalmers University of Technology, S-412 96 Göteborg
Allan T. Emrén
Affiliation:
Department of Nuclear Chemistry, Chalmers University of Technology, S-412 96 Göteborg
Anders Samuelsson
Affiliation:
Department of Nuclear Chemistry, Chalmers University of Technology, S-412 96 Göteborg
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Abstract

The use of computer simulations in the performance assessment for arepository for spent nuclear fuel, are in many cases the only method to getinformation on how the rock-repository system will work. One importantfactor is the solubility of the elements released if the repository isbreached. This solubility may be determined experimentally or simulated.Ifit is simulated, several factors such as thermodynamical uncertaintieswill affect the reliability of the results. If these uncertainties areassumed to be small, the composition of the water used in the calculationsmay play a major part in the uncertainties in solubility. The watercomposition, in tum, is either determined experimentally or calculatedthrough water-rock interactions. Thus, if the mineral composition of therock is known, it is possible to foresee the water composition. However, inmost cases a determination of the rock composition is made from drillingcores and is thus quite uncertain. Therefore, if solubility calculations areto be based on water properties calculated from rock-water interactionsanother uncertainty is introduced. This paper is focused on uncertainty andsensitivity analysis of rock-water interaction simulations and theuncertainties thus obtained are propagated through a program makinguncertainty and sensitivity analysis of the solubility calculations. In bothcases the latin hypercube sampling technique have been used. The resultsshow that the solubilities are in most cases log normal distributed whilethe different elements in the simulated groundwater in some cases divergesignificantly from such a distribution. The numerical results are comfortingin that the uncertainty intervals of the solubilities are rather small, i.e.up to 30%.

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Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 465: Symposium II – Scienfific Basis for Nuclear Waste Management XX , 1996 , 735
Copyright
Copyright © Materials Research Society 1997

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References

REFERENCES

1. Helton, J. C., Uncertainty and sensitivity analysis techniques for use in performance assessment for radioactive waste disposal, Reliability Engineering and System Safety, 42, p. 327–367, 1993.10.1016/0951-8320(93)90097-IGoogle Scholar
2. Iman, R. L., Helton, J. C., Comparison of Uncertainty and Sensitivity Analysis for Computer Models., Rep. NUREG/CR-3904, Sandia National Laboratories, Albuquerque, NM, 1985.Google Scholar
3. Kleijnen, J. P. C., Sensitivity Analysis, Uncertainty Analysis, and Validation: a Survey of Statistical Techniques and Case Studies. Proceedings of the Symposium on Theory and Applications of Sensitivity Analysis of Model Output in Computer Simulations (SAMO), Belgirate, Italy, September, 1995.Google Scholar
4. Emrén, A. T., CRACKER - A program coupling chemistry and transport Version 92–11, SKI TR 93: 6. The Swedish Nuclear Power Inspectorate (SKI), S-106 58 Stockholm, Sweden, 1992.Google Scholar
5. Parkhurst, D. L., Thorstenson, D. C., Plummer, N. L., PHREEOE - A computer program for geochemical calculations., Water-Resources Investigations 80–96, U. S. Geological Survey, 1990.Google Scholar
6. Ekberg, C., Skarnemark, G., Emrén, A. T. and Lundén, I., Uncertainty and sensitivity analysis of solubility calculations at elevated temperatures, Scientific Basis for Nuclear Waste Management XIX, Materials Research Society Symposium proceedings, 1995.10.1557/PROC-412-889Google Scholar
7. Ekberg, C., Lundén, I., Uncertainty analysis for some actinides under groundwater conditions., to be published in the Journal of Statistical Computation and Simulation, 1996.Google Scholar
8. Ekberg, C., Emrén, A. T. and Samuelsson, A., Tools for Uncertainty Analyses of Solubility Calculations in Geological Systems, In preparation, 1997.Google Scholar
9. Smellie, J., Laaksoharju, M., The Äspõ Hard Rock Laboratory, final evaluation of the hydrochemical pre-investigations in relation to existing geologic and hydraulic conditions, Swedish Nuclear Fuel and Waste Management co. (SKB), TR 92–31 Stockholm, 1992.Google Scholar
10. Nilsson, A-C., Groundwater chemistry monitoring at Aspo during 1991, Swedish Nuclear Fuel and Waste Management Co. (SKB), progress report, 1992.Google Scholar
11. Tullborg, E-L., personal communication, TERRALOGICA AB, Gråbo, 1995.Google Scholar
12. Ekberg, C., SENVAR: a Code for Handling Chemical Uncertainties in Solubility Calculations, SKI report 95: 18, Swedish Nuclear Power Inspectorate (SKI), Stockholm, 1995.Google Scholar
13. Samuelsson, A., Diploma thesis, Department of Nuclear Chemistry, Chalmers University of Technology, S 41296, Göteborg, Sweden, in preparation.Google Scholar
14. Nilsson, A-C., Personal communication, Dept. Inorganic Chemisty, Royal Technical Institute, 1995.Google Scholar
15. Arthur, R., Emrén, A.T., Glynn, P. and McMurry, J., The modeler's influence on results for calculated Plutoniumf IV) Hydroxide Solubility in Hypothetical Environments at the Äspö Hard-Rock Laboratory, SKI Report in preparation, SKI, Stockholm, 1996.Google Scholar