A Numerical Sensitivity Analysis to Bentonite Parameters for a Long Term Geochemical Evolution of a HLW Repository in Clay

Abstract:

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Deep geological disposal (DGD) is selected for the long-term confinement of high-level radioactive waste (HLW) by many countries. Safety assessment of nuclear waste disposal in a deep geological repository requires understanding and quantifying radionuclide behavior through the hosting geological formation. This paper presents a numerical model to deal with the pore water composition in bentonite barrier in the evolving geochemical environment which includes bentonite, concrete and clay in a high level radioactive waste repository designed in clay formation, the model considers the following processes: advection, diffusion, aqueous complexation, mineral dissolution/precipitation and cation exchange. Bentonite porosity changes caused by mineral dissolution/precipitation reactions are taken into account in the model. The numerical sensitivity analysis to the accessible porosity of bentonite are performed, the results illustrate that the pH in bentonite is sensitive to changes in accessible porosity of bentonite, the concentrations of aqueous species are sensitive to bentonite porosity before 1000 years, and the effective diffusion coefficient of bentonite controls the extent of high pH plume in bentonite.

Info:

Periodical:

Advanced Materials Research (Volumes 356-360)

Edited by:

Hexing Li, Qunjie Xu and Daquan Zhang

Pages:

1258-1261

DOI:

10.4028/www.scientific.net/AMR.356-360.1258

Citation:

Q. C. Yang et al., "A Numerical Sensitivity Analysis to Bentonite Parameters for a Long Term Geochemical Evolution of a HLW Repository in Clay", Advanced Materials Research, Vols. 356-360, pp. 1258-1261, 2012

Online since:

October 2011

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$35.00

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