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Title: Conceptual Design of HP-STMCs Space Reactor Power System for 110 kWe

A conceptual design of a Heat Pipe-Segmented Thermoelectric Module Converters (HP-STMCs) space reactor power system (SRPS) for a net power of 110 kWe is developed. The parametric analysis changed the number of radiator's potassium heat pipes from 224 to 336 and calculated the effects on the operation parameters and total mass of the system. The reactor has a hexagonal core comprised of 126 heat pipe modules, each consists of three UN, 1.5 cm OD fuel pins brazed to a central lithium heat pipe of identical diameter. The Re cladding of the fuel pins is brazed along the active core length to the lithium heat pipe using 6 Re tri-cusps. The reactor control is accomplished using 12 B4C/BeO control drums, a large diameter one on each side of the hexagonal core and a small diameter one at each corner. The control drums are placed within the radial BeO reflector (7.1-9.1 cm thick). The fuel pin peak-to-average power ratio in the reactor core is 1.12-1.19. Despite its very high density and fabrication challenge, using rhenium structure in the reactor core is necessary for three main reasons: (a) the high reactor temperature ({>=} 1500 K); (b) excellent compatibility with the UN fuel andmore » lithium; (c) to cause a spectrum shift that ensures having sufficient negative reactivity margin during a water submersion accident. The reference HP-STMC system with 324, 2.42-3.03 cm OD potassium heat pipes in the radiator is 9.60 m long and has a cone angle of 30 deg. The nominal operation of the reactor's lithium heat pipes and of the radiator's potassium heat pipes is at or below {approx} 45% of the prevailing wicking and sonic limit, respectively. The masses of the reactor and radiation shadow shield are 753.7 kg and 999.5 kg, respectively; the average heat pipes temperature in the reactor is 1513 K; the mass of the reactor's lithium heat pipes with a C-C finned condenser that is 1.5 m long is 516.1 kg; the mass of the radiator is 557.5 kg, with an outer surface area of 87 m2 (6.41 kg/m2) and effective temperatures of 752 K and 734 K for the front and rear radiator sections, respectively. These estimates are for a constant collector temperature for the STMCs of 1300 K and STMCs' thermal and electrical losses of 5% and 8%, respectively. The estimates of the total mass and specific power of the reference HP-STMCs SRPS, pending future detailed design and analysis, are 4261 kg and 25.8 We/kg, respectively.« less
Authors:
;  [1] ;  [2]
  1. Institute for Space and Nuclear Power Studies, University of New Mexico, Albuquerque, NM, 87131 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
20632874
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 699; Journal Issue: 1; Conference: STAIF 2004: 21. symposium on space nuclear power and propulsion: Human space exploration, space colonization, new frontiers and future concepts, Albuquerque, NM (United States), 8-11 Feb 2004; Other Information: DOI: 10.1063/1.1649628; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; 22 GENERAL STUDIES OF NUCLEAR REACTORS; BERYLLIUM OXIDES; DESIGN; FISSION; FUEL PINS; HEAT PIPES; LITHIUM; NUCLEAR FUELS; PARAMETRIC ANALYSIS; POTASSIUM; POWER SYSTEMS; RADIATION PROTECTION; RADIATORS; REACTIVITY; REACTOR CORES; REACTOR OPERATION; RHENIUM; SPACE POWER REACTORS; SPACE VEHICLES; TEMPERATURE DISTRIBUTION; THERMOELECTRIC CONVERSION NESDPS Office of Nuclear Energy Space and Defense Power Systems