Design and Analysis of a 20 kWe Yttrium Hydride Moderated Lunar Reactor Power System

As a significant research direction within the field of space energy, nuclear reactor power sources offer novel solutions to space energy demands through their high-power density and robust environmental adaptability. China's lunar exploration program commenced in 2004, having accomplished multiple preliminary mission objectives and advancing towards the construction of a lunar research station with long-term operational capability. This paper addresses the energy requirements of future lunar research stations by proposing a 20 kWe lunar nuclear power system utilizing yttrium hydride moderator. System modelling and steady-state calculations of the reactor core were conducted using the FLUENT program, verifying that the designed core structure meets the specified requirements. Furthermore, an enhanced transient analysis program was employed to simulate and analyze critical reactor systems, including the coolant circuit and radiator heat dissipation system. This investigation examined the overall system response and key parameters under typical accident conditions, demonstrating the reactor's capability for safely shutdown and effective heat removal during such events. These findings validate the design's rationality and safety.