Abstract
Transport of iodide and sodium has been studied by means of block
fracture and core column experiments to evaluate the simplified
radionuclide transport concept. The objectives were to examine the
processes causing retention in solute transport, especially matrix
diffusion, and to estimate their importance during transport in
different scales and flow conditions. Block experiments were performed
using a Kuru Grey granite block having a horizontally planar natural
fracture. Core columns were constructed from cores drilled orthogonal to
the fracture of the granite block. Several tracer tests were performed
using uranine, 131I and 22Na as tracers at water flow rates 0.7–50 μL min−1.
Transport of tracers was modelled by applying the advection–dispersion
model based on the generalized Taylor dispersion added with matrix
diffusion. Scoping calculations were combined with experiments to test
the model concepts. Two different experimental configurations could be
modelled applying consistent transport processes and parameters. The
processes, advection–dispersion and matrix diffusion, were
conceptualized with sufficient accuracy to replicate the experimental
results. The effects of matrix diffusion were demonstrated on the
slightly sorbing sodium and mobile iodine breakthrough curves.
Original language | English |
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Pages (from-to) | 983 - 990 |
Number of pages | 8 |
Journal | Physics and Chemistry of the Earth: Parts A/B/C |
Volume | 33 |
Issue number | 14-16 |
DOIs | |
Publication status | Published - 2008 |
MoE publication type | A1 Journal article-refereed |
Keywords
- Block-scale experiments
- Crystalline rock
- Matrix diffusion
- Migration