Optimization and Simulation of Startup Control for Space Nuclear Power Systems with Closed Brayton Cycle based on NuHeXSys

Abstract: This paper presents the development and optimization of a Space Nuclear Power System (SNPS) utilizing a helium-xenon gas-cooled Closed Brayton Cycle (CBC). A comprehensive dynamic system analysis code NuHeXSys (Nuclear Helium-Xenon Brayton Cycle Power System) was created, integrating non-ideal gas properties, a multi-channel thermal-hydraulic reactor core, and detailed turbo-machinery components. The innovation lies in parametrization of startup control sequence and application of an evolutionary algorithm (NSGA-II) to improve control performance, significantly reducing startup time and energy consumption. Model verification shows parameter deviations within 10%, confirming its accuracy. The optimized control strategy reduced startup time by 1260 seconds and lowered external energy demand by 17%, demonstrating improved efficiency and operational stability for deep space missions. This work provides a foundation for future advancements in optimizing space nuclear power systems.