Neutronic Analysis of BEAVRS PWR at Hot Zero Power Condition and Validation of SuperMC for PWR Assembly using OpenMC

Abstract

This paper contains various neutronic analysis on a pressurized water reactor (PWR). The model used in this work is Benchmark for Evaluation And Validation of Reactor Simulations (BEAVRS) PWR with a thermal power of 3411 MW. The BEAVRS benchmark gives precise information about the two cycles of the 4-loop Westinghouse PWR core for hot full power and hot zero power conditions. Open-source Monte Carlo particle transport code, OpenMC and demo version of a Monte Carlo code, SuperMC have been used to determine the neutronic parameters and generate respective graphs. Several nuclear cross-section libraries, including ENDF/B-VIII.0, and JEFF-3.3 were used to calculate various neutronic parameters for continuous energy source which includes the effective multiplication factor, changes in reactor parameters for various temperatures and enrichments of fuel element, Shannon entropy, fuel assembly burnup calculations, fission rate, flux per lethargy and thermal neutron flux distribution across the core. Effective multiplication factor for different nuclear cross section libraries was compared to visualize differences. Criticality change due to various modifications in geometry such as- core barrel, neutron shield panel, control rods, and burnable absorbers have been observed. This paper also intends to validate the OpenMC calculated neutronic code on BEAVRS PWR as it is a detailed benchmark designed to validate and evaluate high-fidelity reactor simulation tools. Burnup of a pre-build 7x7 PWR alike assembly was analyzed using SuperMC interface and was later re-constructed in OpenMC for validation of the burnup results. For the source type, point source was selected at the centre of the assembly to run the simulation. Then a comparison between OpenMC and SuperMC burnup results with different particle number have been conducted to validate the SuperMC code.