Consistency of the strontium transport parameters in Boom Clay obtained from different types of migration experiments

Research outputpeer-review

Abstract

The consistency of migration parameters obtained by different methods is examined for strontium in Boom Clay. In addition to a previous in-situ percolation experiment and electromigration experiments (using an electrical field as driving force), a lab percolation test and two through-diffusion tests (on clay cores of different lengths) have been performed. All experiments lead to a robust value for the apparent diffusion coefficient of strontium between 5E 10-12 m2/s and 1E 10-11 m2/s. No reliable value is obtained for the product ηR of the diffusion accessible porosity η and the retardation factor R. For one of the through-diffusion experiments, the concentration decrease in the inlet as a function of time was fitted simultaneously with the strontium profile in the clay, leading to a ηR value around 400. Estimating ηR at the inlet/clay interface as the ratio of the bulk concentration and the pore water concentration leads to a similar value. The values obtained from the strontium profiles in the percolation and electromigration experiments are in line as well. However, fitting for both through-diffusion tests the outlet concentrations versus time leads io very low and unrealistic values of ηR (0.15 and 0.5). Modeling shows that the transport of strontium in Boom Clay cannot be satisfactorily described with the current assumptions (like e.g. instantaneous linear sorption equilibrium and boundary conditions), meaning that there is a problem to obtain a reliable value for the product ηR for strontium in Boom Clay.

Original languageEnglish
Title of host publicationScientific Basis for Nuclear Waste Management XXXIII
Subtitle of host publicationSymposium Proceedings
Place of PublicationWarrendale, PA, United States
PublisherMaterials Research Society
Pages421-428
Number of pages8
Volume1193
ISBN (Print)9781605111667
DOIs
StatePublished - 2009
Event33rd International Symposium "Scientific Basis for Nuclear Waste Management". MRS - V.G. Khlopin Radium Institute, St. Petersburg
Duration: 24 May 200929 May 2009

Publication series

NameMaterials Research Society Symposium Proceedings
Volume1193
ISSN (Print)0272-9172

Conference

Conference33rd International Symposium "Scientific Basis for Nuclear Waste Management". MRS
Country/TerritoryRussian Federation
CitySt. Petersburg
Period2009-05-242009-05-29

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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