PERFORMANCE IMPROVEMENTS TO THE 2D/1D SUBPLANE METHOD IN MPACT

摘要

Recent work in MPACT, the primary deterministic neutron transport solver in CASL’s VERA, hasfocused on significantly improving the overall performance of the calculations and manycomponents within the code have been improved. The paper focuses on the most recentdevelopment to improve the 2D/1D subplane method in preparation for a production-levelcapability. The key developments presented here focus on incorporating a multilevel-in-spaceCMFD solver that also collapses on the subplane bases, a dynamic subplane meshing capabilitythat better preserves accuracy during control rod movements, and overall usability improvementsto make using the subplane method seamless. Compared to the current default 2D/1D solver inMPACT, substantial improvements are demonstrated on two progression problems, including astandard quarter core model, where potential savings observed at ～2× in memory and ～5-6× incore-hour requirements.