Research on Monte Carlo Particle Transport Method Directly Using CAD Geometry

Constructive solid geometry (CSG) is usually used to model in traditional Monte Carlo programs. However, it is very difficult and time-consuming to use CSG to accurately model some complex high-order surfaces. In order to solve this problem, a Monte Carlo method (direct accelerated geometry Monte Carlo, DAGMC) that directly used CAD geometric modeling was proposed to perform particle transport calculations. Based on Monte Carlo program RMC, the DAG-RMC program using CAD geometry was developed, and three models of block assembly, fuel rod and Utah teapot were calculated and analysed using DAG-RMC program. The results show that the calculation results of DAG-RMC are in good agreement with the results of the traditional CSG modeling method and OpenMC program, verifying the correctness of the DAG-RMC in particle transport and critical calculation.