[H-CG31] Nuclear Energy and Geoscience

[HCG31-P04] Diffusion Coefficient and Porosity of Granite for Evaluation of Mobility Parameter

*Kenji Fukuda¹, Hiroaki Murakami¹, Kaori Itai², Masayuki Ishibashi¹, Eiji Sasao¹ (1.Japan Atomic Energy Agency, 2.C･TECH corporation)

Keywords:granite, Effective diffusion coefficient, uranine, porosity

Matrix diffusion is one of the important for evaluating solute transport in granite. Diffusion of ions in granite pore water was studied in order to evaluate diffusivity in rock. Effective diffusion coefficient of uranine was measured using a diffusion cell. The effective diffusion coefficient of uranine in granite without fissure and alteration was found to be in the range 10^-15 to 10^-13 m² s^-1. The porosities of the granite samples were determined by observation of petrographic thin sections using entity fluorescence microscope. There was a positive correlation between the porosity larger than 1% and the effective diffusion coefficient.