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

TL;DR

This paper introduces a CAD-based automatic geometry modeling method for the method of characteristics in neutron transport calculations, improving modeling accuracy and applicability to complex geometries.

Contribution

A novel CAD-based modeling approach integrated with MOC for neutron transport, enhancing geometry handling and ray tracing in complex configurations.

Findings

Demonstrated feasibility of the CAD-based MOC method

Reduced spatial discretization errors with diamond-difference scheme

Successfully integrated into SuperMC system

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, whic h 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.