Autonomous Load Following and Operational Aspects of the Star-LM HLMC Natural Convection Reactor

STAR-LM is a 300 to 400 MWt class modular, fully transportable, proliferation resistant, and passively safe reactor system that offers developing nations and power producers nearly autonomous operation for very long term. Autonomous load following is the ability of the reactor core power to adjust itself to match the heat removal as a consequence of inherent physical phenomena. STAR-LM achieves autonomous load following through the utilization of a fast neutron spectrum core, inert lead-bismuth eutectic primary coolant, high thermal conductivity transuranic nitride fuel, and 100+% natural circulation heat transport of the primary coolant. To investigate and demonstrate autonomous operation as well as other operational aspects, representative operational transients are analyzed for the 300 MWt STAR-LM design using a coupled thermal hydraulics-neutron kinetics plant dynamics analysis computer code. Autonomous load following without reactivity effects from control rods is demonstrated for decrease-in-turbine load and increase-in-turbine load transients. For initial startup, startup from hot standby, and normal shutdown transients effected by withdrawal or insertion of shutdown rods, the reactor transitions stably to the desired steady state.