Nuclear design analysis of square-lattice honeycomb space nuclear rocket engine

Journal Article · Fri Jan 22 00:00:00 EST 1999 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.57549· OSTI ID:21202511

Widargo, Reza; Anghaie, Samim ^[1]

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1. Innovative Nuclear Space Power and Propulsion Institute, University of Florida, 202 NSC, Gainesville, Florida 32611-8300 (United States)

The square-lattice honeycomb reactor is designed based on a cylindrical core that is determined to have critical diameter and length of 0.50 m and 0.50 c, respectively. A 0.10-cm thick radial graphite reflector, in addition to a 0.20-m thick axial graphite reflector are used to reduce neutron leakage from the reactor. The core is fueled with solid solution of 93% enriched (U, Zr, Nb)C, which is one of several ternary uranium carbides that are considered for this concept. The fuel is to be fabricated as 2 mm grooved (U, Zr, Nb)C wafers. The fuel wafers are used to form square-lattice honeycomb fuel assemblies, 0.10 m in length with 30% cross-sectional flow area. Five fuel assemblies are stacked up axially to form the reactor core. Based on the 30% void fraction, the width of the square flow channel is about 1.3 mm. The hydrogen propellant is passed through these flow channels and removes the heat from the reactor core. To perform nuclear design analysis, a series of neutron transport and diffusion codes are used. The preliminary results are obtained using a simple four-group cross-section model. To optimize the nuclear design, the fuel densities are varied for each assembly. Tantalum, hafnium and tungsten are considered and used as a replacement for niobium in fuel material to provide water submersion sub-criticality for the reactor. Axial and radial neutron flux and power density distributions are calculated for the core. Results of the neutronic analysis indicate that the core has a relatively fast spectrum. From the results of the thermal hydraulic analyses, eight axial temperature zones are chosen for the calculation of group average cross-sections. An iterative process is conducted to couple the neutronic calculations with the thermal hydraulics calculations. Results of the nuclear design analysis indicate that a compact core can be designed based on ternary uranium carbide square-lattice honeycomb fuel. This design provides a relatively high thrust to weight ratio.

• OSTI ID: 21202511
• Journal Information: AIP Conference Proceedings, Vol. 458, Issue 1; Conference: Space technology and applications international forum - 1999, Albuquerque, NM (United States), 31 Jan - 4 Feb 1999; Other Information: DOI: 10.1063/1.57549; (c) 1999 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
CRITICALITY
DESIGN
FUEL ASSEMBLIES
HAFNIUM
ITERATIVE METHODS
MIXED CARBIDE FUELS
NEUTRON FLUX
NEUTRON LEAKAGE
NEUTRON TRANSPORT
NIOBIUM
NUCLEAR ENGINEERING
PROPULSION SYSTEMS
REACTOR CORES
ROCKET ENGINES
SOLID SOLUTIONS
SPACE POWER REACTORS
TANTALUM
THERMAL HYDRAULICS
TUNGSTEN
URANIUM CARBIDES
NESDPS Office of Nuclear Energy Space and Defense Power Systems