Power Optimization in the STAR-LM Modular Natural Convection Reactor System

Abstract

STAR-LM is a modular, factory-fabricated, overland transportable, proliferation resistant, autonomous load following, and passively safe liquid metal-cooled fast reactor system that utilizes inert lead-bismuth eutectic coolant combined with 100+% natural circulation heat transport to achieve radial design simplification, enhanced reliability, and cost savings. STAR-LM has the potential to meet all of the U.S.DOE Generation IV goals of sustainable energy development, safety and reliability, and economics. Previous development of STAR-LM resulted in a 300 MWt modular pool type reactor in which modular steam generators are immersed directly inside the primary coolant and the core is part of a reactor module/flow-thru fuel cartridge that provides no access to fuel during the core lifetime. Recent concept development has focused on raising the power achievable in a small module size based on preserving key criteria for: i) full spectrum of modes of module transport from factory to site (including rail transport); ii) ultralong core cartridge lifetime; iii) 100% natural circulation heat transport; and iv) coolant and cladding peak temperatures well within the existing (mainly Russian) database for lead-bismuth eutectic coolant and ferritic steel core materials. For example, natural circulation is found to be capable of transporting 400 MWt in a fully transportable module size with 15 year core life (at 100% capacity factor;100,000 MWd/tonne average burnup; 1.5 peaking factor) with a core outlet temperature of 489 C, peak cladding inner surface temperature of 580 C, and steam outlet superheat of 82 C at 10 MPa.