[2B01-05] Criticality Safety (Fuel Debris)

[2B03] Delta Tracking Monte Carlo Neutron Transport with Voxel Mesh Overlay

*TARO UEKI¹ (1. JAEA)

Keywords:delta-tracking, Monte Carlo, voxel, index search, random media

In this excerpt, it is shown that the delta-tracking combined with a voxel mesh and an index search is an efficient tool for the reactor physics analysis of random media. The essential idea is the use of delta-tracking in a selected region consisting of a base material where voxel mesh is overlaid, a particle flights by ignoring the mesh cell boundaries, and a fast index search is applied at the flight destination to identify where the particle is. It turns out that computational time remains the same over numbers of voxel mesh cells from 10⁴ to 10¹¹. Numerical results are demonstrated in terms of the criticality analysis of the random substitution of SUS304 in fuel debris.