A Novel Algorithm for CAD to CSG Conversion in McCAD

Abstract

Modeling and simulation lie at the heart of the design process of any nuclear application. An accurate representation of the radiation environment ensures not only the feasibility of new technologies, but it also aids in operation, maintenance, and even decommissioning. With increasingly complex designs, high-fidelity models have become a necessity for design maturity. McCAD has been under development for many years at Karlsruhe Institute of Technology (KIT) to facilitate the process of generating suitable models for nuclear analyses. In this paper, an overview of the major advances in the new version of the code is presented. A novel conversion algorithm has proven to be robust in significantly reducing the processing time to generate radiation transport models, making it easier to iterate on design details. A first-of-a-kind capability to generate hierarchical void cells is also discussed with preliminary analysis showing performance gains for particle tracking.

CAD and constructive solid geometry modeling of the Molten Salt Reactor Experiment with OpenMC

“…The first approach involves converting the internal representation of a CAD model (boundary representation) to the native CSG representation used in MC codes. This approach has been around since at least 2005 (Tsige- Tamirat and Fischer, 2005); specific software packages for performing CAD-to-CSG conversion include McCAD (Harb et al, 2023), MCAM (Wang et al, 2014), GEOMIT (Nasif et al, 2012), CMGC (Wang et al, 2020), SuperMC (Wu et al, 2015), and GEOUNED (García et al, 2021). Of these packages, McCAD 1 and GEOUNED 2 are available under an open-source license.…”