Monte Carlo simulation of radionuclide migration in fractured rock for the performance assessment of radioactive waste repositories

Abstract The estimation of radionuclide migration within a fractured medium is a fundamental task in any performance assessment aimed at verifying the protection offered by radioactive waste repositories. In this paper, we present a novel application of a dual-permeability, Monte Carlo simulation approach based on Kolmogorov–Dmitriev (KD) theory of branching stochastic processes. The Monte Carlo simulation scheme allows to easily handle the high degree of complexity of the problem, accounting for non-homogeneities both in space and time. Particular attention is devoted here to the inclusion of time-dependencies. An illustration is given with reference to a realistic case study of 239 Pu migration.