Preliminary study on CAD-based method of characteristics for neutron transport calculation

Abstract

Abstract:The method of characteristics (MOC) is widely used for neutron transport calculation in recent decades. However, the key problem determining whether MOC can be applied in highly heterogeneous geometry is how to combine an effective geometry modeling method with it. Most of the existing MOC codes conventionally describe the geometry model just by lines and arcs with extensive input data. Thus they have difficulty in geometry modeling and ray tracing for complicated geometries.In this study, a new method making use of a CAD-based automatic modeling tool MCAM which is a CAD/Image-based Automatic Modeling Program for Neutronics and Radiation Transport developed by FDS Team in China was introduced for geometry modeling and ray tracing of particle transport to remove those limitations. The diamond-difference scheme was applied to MOC to reduce the spatial discretization errors of the flat flux approximation. Based on MCAM and MOC, a new MOC code was developed and integrated into SuperMC system, which is a Super Multi-function Computational system for neutronics and radiation simulation. The numerical results demonstrated the feasibility and effectiveness of the new method for neutron transport calculation in MOC.

Application of MC-MC Coupled Method in Neutron Shielding Analysis of Reactor Pit in Reactor Building

“…Due to the structural complexity and large-scale characteristics in nuclear power plant (NPP), neutron shielding problems with large and complex geometric is usually solved by coupled multi-dimensional calculation method [4][5][6]. Therefore, the MC-MC coupled method, which can decompose one model into continuous parts, is established to solve this type of problem.…”

Optimal Spatial Subdivision method for improving geometry navigation performance in Monte Carlo particle transport simulation

“…The method has been implemented and integrated into the Super Monte Carlo program (SuperMC) (Song et al, 2014;Sun et al, 2013;Wu et al, 2014), which is a CAD-based multi-functional simulation system for nuclear and radiation process (Wu et al, 2011;Wu, 2008Wu, , 2007. The program SuperMC, which integrates automatic modeling (Hu et al, 2007;Li et al, 2007;Wu, 2009), multi-physics simulation and visualized analysis as a systematical system, based on hybrid Monte Carlo and deterministic transport methods (Chen et al, 2014;Wu et al, 1999), is designed to perform radiation transport, isotope burn-up and material activation simulations (Huang et al, 2009(Huang et al, , 2004.…”