SimpleMOC - A performance abstraction for 3D MOC

Abstract

The method of characteristics (MOC) is a popular method for efficiently solving two-dimensional reactor problems. Extensions to three dimensions have been attempted with mitigated success bringing into question the ability of performing efficient full core three-dimensional (3D) analysis. Although the 3D problem presents many computational difficulties, some simplifications can be made that allow for more efficient computation. In this investigation, we present SimpleMOC, a “mini-app” which mimics the computational performance of a full 3D MOC solver without involving the full physics perspective, allowing for a more straightforward analysis of the computational challenges. A variety of simplifications are implemented that are intended to increase the computational feasibility, including the formation axially-quadratic neutron sources. With the addition of the quadratic approximation to the neutron source, 3D MOC is cast as a CPU-intensive method with the potential for remarkable scalability on next generation computing architectures.