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  • 1 National Tsing Hua University Department of Biomedical Engineering and Environmental Sciences Hsinchu 30013 Taiwan
  • 2 Graduate School of Engineering, Tohoku University Department of Quantum Science and Energy Engineering Aramaki-Aza-Aoba 6-6-01-2 Sendai 980-8579 Japan
  • 3 National Tsing Hua University Nuclear Science and Technology Development Center Hsinchu 30013 Taiwan
  • 4 National Tsing Hua University Department of Engineering and System Science Hsinchu 30013 Taiwan
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Abstract  

In this study, the diffusion behavior of cesium and selenium with 10−4M concentration in mudrock was studied by trough-diffusion tests and summarized in order to provide confidence on long-term performance assessment of nuclear waste repositories. The diffusion process of Cs and Se reached equilibrium after 60 and 500 days, respectively. Besides, it also displays that the distribution coefficients (Kd) of Se in through-diffusion tests is higher than that of Cs in agreement with that obtained from the batch method. The Kd value (15.14±1.99 mL/g) of Cs by diffusion techniques is equivalent to that of batch method (15.10±0.40 mL/g) because sorption of Cs was assumed to fast sorption step. However, the Kd value of Se (137.58±12.20 mL/g) derived from the diffusion technique is higher than that from batch tests (76.72±2.96) and showed an obvious variation with Kd of Cs. The difference of Kd between diffusion and batch methods resulted from the fact that 14 days were not long enough to reach equilibrium or stable state in the batch method.