Modelé d'advection -dispersion fractionnaire pour le transport anormal des radionucléides dans un système de dépôt en couche.

Abstract

This work proposes fractional advection-dispersion equation for the simulation of radionuclide anomalous migration in low-permeability porous media with multiple barriers, a key concept in deep geological disposal of high-level waste. The presented fractional advection-dispersion models utilize various definitions of fractional derivatives and are analyzed using the Laplace integral transform method. The comparison of the results obtained with measurements from experiments conducted in liquid columns indicates that the model is reliable. Furthermore, it demonstrates that the fractional model provides a better description of the transport of radionuclides in layered deposition sites by incorporating various dispersion phenomena. The results also reveal that the fractional parameter significantly influences the spatial distribution of radionuclides within the repository site. The observed concentration gaps depend on the definition of the fractional derivative used. This research lays a theoretical foundation for further simulations of radionuclide migration in a multi-barrier system within high-level waste repositories.