Nuclear-Coupled Thermal Hydraulics Stability of a Natural Circulation Lead-Cooled Fast Reactor

Stability analyses are carried out for a natural circulation lead-cooled fast reactor which is at its design stage. Because of its natural circulation feature, flow stability as well as nuclear-coupled thermal hydraulics stability is of some concern. Modal Expansion Method (MEM) and Reduced Order Model (ROM) are used for neutronics and thermal hydraulics part, respectively. These two separate models are coupled through feedback effects. Different simulation scenarios on the separate and coupled models are reported.