Numerical simulation of radionuclide particle tracking based on discrete fracture network

The migration of high-level radioactive waste in fracture media during geological disposal has caused widespread concern, and the numerical simulation of radionuclide particle transport is an important research methods. Current flow simulation methods of fractured media are mainly equivalent continuum model, the dual media model and the discrete fracture network model. For the rock scale studies, the first two models view the fracture media as a continuous medium, cannot adequately represent fractured anisotropic media and discontinuities features. Therefore, this study constructed numerical simulation method of radionuclide particle migration based on the discrete fracture network model, in combination with the Monte Carlo method, the finite element method and the radionuclide particle transport model. We carry out this study of alternative high-level nuclear waste site(Alax) and calculated radionuclide particle migration results. The results show that for the established numerical model, the pathway lengths of radionuclide particles in the model are averaged 1293.35 m, which spent an average time of 1.70×1011 days. Drilling data are used in this study to verify the reliability of the model, and the above results prove that the radionuclide particle simulation method we constructed can be used to predict the high-level radioactive migration in waste disposal site. This study can provide a reference for selecting the geological repository of high-level radioactive waste.