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.

Conceptual core design study of an innovative small transportable lead-bismuth cooled fast reactor (SPARK) for remote power supply

“…The attractive features of SMRs include lower absolute overnight capital costs, fitness for small electricity grids, reduced infrastructure and staff requirements, possibility to incremental capacity increase, and possible non‐electric applications (potable water production, district heating, or hydrogen production) . Various design concepts of SMRs have been proposed based on the pressurized water reactor, the boiling water reactor, the liquid metal cooled fast reactor (LMFR), the gas cooled fast reactor, and the molten salt reactor technologies . Among all the SMR design concepts, the LMFR‐type SMR is considered as a competitive technology for the following advantages: the easy‐to‐implement long time operation, enhanced passive safety due to the operation of coolant near the atmospheric pressure and the negative reactivity feedback from fuel and core structure expansion, and simple reactivity control without concerns of fission products poisoning …”

Passive Safety of the STAR-LM HLMC Natural Convection Reactor

“…3 The main purpose of the present work is to investigate and demonstrate the passive safety features of STAR-LM for a representative set of postulated accidents using a coupled thermal hydraulics-neutron kinetics plant dynamics analysis computer code.…”

“…The low power density core facilitates heat removal by the LBE coolant through large hydraulic diameter coolant channels reducing the core pressure drop such that more than 400 MWt can be transported from the core to the steam generator by natural circulation of the primary coolant. 3,6 Elimination of main circulation pumps eliminates an entire class of accidents involving reduction/loss of forced flow that would otherwise need to be addressed in a risk assessment and enhances simplification, reliability, economics, and passive safety. The core design features an open core without individual subassemblies; accidents involving blockage of a subassembly have been eliminated.…”

Application of Seismic Isolation to the STAR-LM Reactor

“…The Secure, Transportable, Autonomous Reactor-Liquid Metal (STAR-LM), which is described in [1][2][3][4], is a small reactor module for steam supply of 300 MWth using lead-bismuth as a heavy liquid metal coolant. The reactor structure for STAR-LM includes a reactor module, four steam generators, a coolant module and a guard vessel and is shown in Figure1.…”

“…Much research was performed on their isolation systems (1) to quantify elastomer response characteristics, (2) to identify optimal mounting methods and (3) to determine system and isolator design parameters. There has not been any work done on the lead cooled designs.…”