Proceedings of the KNS autumn meeting, 2010
Conventional Monte Carlo (MC) codes use the text based geometry input system. However, two difficulties can be found as the result of adopting text based geometry input system. One is a user's burden for writing a complex geometric data in the text file, and the other is the limited capability of modeling the geometry due to the usage of predefined types of surfaces in the MC codes. To lessen the burden for users to write geometric input files, and to utilize the convenience of CAD software in modeling 3D shapes, interfacing codes which converts CAD file into MCNP input file have been developed. However this approach still shows limitation of geometric capability because the CAD model is converted into combinations of the predefined types of surfaces. Different from the converting approach, well-developed CAD kernels can be embedded in the MC codes for raising the geometric capability of MC codes. In ITER TBM program, Mengkuo applied CGM as the geometric engine of MCNP to use CAD data directly. As like the second approach, this work is to augment the geometric capability of McCARD using OpenCASCADE 6.3, an open source of CAD kernel. By the aid of C++ libraries and development tools supplied in the OpenCASCADE package, the CAD based geometric module for McCARD has been developed. In this paper, we describe technical works for implementing the CAD based geometric module and optimization approaches to accelerate the CAD based MC calculations
