Molecular Dynamics simulation for PBR pebble tracking simulation via a random walk approach using Monte Carlo simulation

Using a Monte Carlo (MC) simulation, random walks were used for pebble tracking in a two-dimensional geometry in the presence of a biased gravity field. We investigated the effect of viscosity damping in the presence of random Gaussian fluctuations. The particle tracks were generated by Molecular Dynamics (MD) simulation for a Pebble Bed Reactor. The MD simulations were conducted in the interaction of noncohesive Hertz–Mindlin theory where the random walk MC simulation has a correlation with the MD simulation. This treatment can easily be extended to include the generation of transient gamma-ray spectra from a single pebble that contains a radioactive tracer. Then the inverse analysis thereof could be made to determine the uncertainty of the realistic measurement of transient positions of that pebble by any given radiation detection system designed for that purpose.

► Particle tracking by Monte Carlo and Molecular Dynamics (MD) simulations. ► The interaction of noncohesive Hertz–Mindlin forces under gravity in PBRs. ► A correlation with trajectories between random walks and MD simulation.