COMPARATIVE ANALYSIS OF PBMR CORE PHYSICS TEST PROBLEMS

The Pebble Bed Modular Reactor (PBMR) configuration is one of the most promising reactor concepts for next generation power reactors, and thus has garnered substantial interest and research investment in the international nuclear community. Further development and maturation of this novel concept demands, among other things, verification of its safety features via reliable, high fidelity physics models and robust, efficient, and accurate computational tools. This has motivated the development of more accurate and efficient tools to analyze the neutronics behavior for the design and safety evaluations of the PBMR In addition to the development of new neutronics methods, this includes defining appropriate benchmarks to verify and validate the new methods in computer codes. This paper addresses the benchmarking of core simulation methods through a set of multi-dimensional computational test problems. The intention is to develop these test problems into HTGR benchmarks similar to the well-known IAEA PWR steady-state benchmarks. The benchmarks developed here were analyzed with three different codes: VSOP, NEM, and PARCS. The results obtained in this study have shown a reasonable agreement between the codes and has also shown that NEM, being a nodal expansion method’s code has the capability to reproduce the results of the VSOP code at reasonable computational cost.