Nuclear modules for space electric propulsion

Journal Article · Thu Jan 01 04:00:00 EST 1998 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.54749· OSTI ID:664636

Difilippo, F C ^[1]

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1. Oak Ridge National Laboratory, P.O. Box 2008, Bldg. 6025, Oak Ridge, Tennessee 37831-6363 (United States)

The analysis of interplanetary cargo and piloted missions requires the calculations of the performances and masses of subsystems to be integrated in a final design. In a preliminary and scoping stage the designer needs to evaluate options in an iterative way by using simulations that run fast on a computer. As a consequence of a collaborative agreement between the National Aeronautic and Space Administration (NASA) and the Oak Ridge National Laboratory (ORNL), ORNL has been involved in the development of models and calculational procedures for the analysis (neutronic and thermal hydraulic) of power sources for nuclear electric propulsion. The nuclear modules will be integrated into the whole simulation of the nuclear electric propulsion system. The vehicles use either a Brayton direct-conversion cycle, using the heated helium from a NERVA-type reactor, or a potassium Rankine cycle, with the working fluid heated on the secondary side of a heat exchanger and lithium on the primary side coming from a fast reactor. Given a set of input conditions, the codes calculate composition, dimensions, volumes, and masses of the core, reflector, control system, pressure vessel, neutron and gamma shields, as well as the thermal hydraulic conditions of the coolant, clad and fuel. Input conditions are power, core life, pressure and temperature of the coolant at the inlet of the core, either the temperature of the coolant at the outlet of the core or the coolant mass flow and the fluences and integrated doses at the cargo area. Using state-of-the-art neutron cross sections and transport codes, a database was created for the neutronic performance of both reactor designs. The free parameters of the models are the moderator/fuel mass ratio for the NERVA reactor and the enrichment and the pitch of the lattice for the fast reactor. Reactivity and energy balance equations are simultaneously solved to find the reactor design. Thermalhydraulic conditions are calculated by solving the one-dimensional versions of the equations of conservation of mass, energy, and momentum with compressible flow. {copyright} {ital 1998 American Institute of Physics.}

• OSTI ID: 664636
• Report Number(s): CONF-980103--
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 420; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
22 GENERAL STUDIES OF NUCLEAR REACTORS
42 ENGINEERING
BRAYTON CYCLE POWER SYSTEMS
COMPUTERIZED SIMULATION
DESIGN
FAST REACTORS
NERVA REACTOR
NESDPS Office of Nuclear Energy Space and Defense Power Systems
PROPULSION
SPACE POWER REACTORS
SPACE VEHICLES