Liquid-Metal Pump Technologies for Nuclear Surface Power

摘要: Kurt A. PolzinNASA-Marshall Space Flight Center, Nuclear Systems Branch, ER-2 4MSFC, AL 35812Tel: 256-544-5513, Fox." 256-544-2216, Email: kurt.a.polzin@nasa.govAbstract - Multiple liquid metal pump options are reviewed for the purpose of determining thetechnologies that best suited inclusion in a nuclear reactor thermal simulator intended torest prototypical space surface power syswm components Conduction, induction andthermoelectric electromagnetic pumps evaluated based on their peubrmance characteristicsand technical issues associated with incorporation into system. A thermoelectricelectromagnene is selected as option use NASA-MSFC's Fission SurfacePower-Primar_ Test Circuit its relative simplicity, low supplymass penalty, flight heritage, and promise increased efficiency over those earlierpump designs through skutterudite thermoelectric elements.I. INTRODUCTIONIt this paper to present survey ofvarious available pumping technologies thatcould be incorporated demonstration fissionsurface reactor. This includes listing thevarious strengths weaknesses each option, andfocuses special attention identifying primarydevelopmental would need addressed andresolved before deployment space-qualified system.The similar but more comprehensive thanthat performed by Determan Baker 1, aimed atproviding recommendations arebest Surface Power-Primary TestCircuit (FSP-PTC) hardware effort atNASA-MSFC. These oncomparisons between capability, reliability, availability,mass. complexity development andimplementation option.For paper, assumptions follows:• Working Fluid: NaK78• Fluid Temperature: 840-800 K• Ap: 7.5-I0 kPa• Volume Flow Rate: 13.2-15 GPM• Operational time: i yeas nominalAll discussed areelectromagnetic nature, meaning body forces aredirectly applied interacting currentsand magnetic fields. Mechanical have been omittedfrom review it desirable avoid wear issues,mechanically induced vibrations, sealing difficultiesassociated incorporating reciprocating or rotatingmachinery flow system aII. REVIEW OF ELECTROMAGNETIC PUMPTECHNOLOGIESElectromagnetic (EM) 3 exploit fact thatliquid metals conducting fluids capable carryingcurrent. By orienting field perpendicular acurrent passing metal, streamwlse jxBLorentz force exerted fluid. has theeffect either accelarating itpasses increasing thepressure head within liquid. relatively universal limiton all EM at velocities exceeding -9.14m/s cavitation occurs, introducing instabilities andoscillations can reduce performance 3.IliA. Conduction PumpsIn conduction pumps, current directly conductedinto fluid electxodes typically attachedto outer wall duct containing metal.There two basic variants direct current(DC) alternating (AC). In both variants, thefluid driven exact same physical processesConsequently, these types share many common lossmechanisms.