Conceptual design of a CERMET NTR fission core using multiphysics modeling techniques

An initial pre-concenptual CERMET Nuclear Thermal Propulsion reactor system is investigated within this paper. Reactor configurations are investigated where the fuel consists of 60 vol.% UO₂ and 40 vol.% W where the UO2 consists of Gd₂O₃ concentrations of 5 and 10 mol.%.Gd₂O₃. The fuel configuration consisting of 5 mol.% UO₂ was found to have a total mass of 2761 kg and a thrust to weight ratio of 4.10 and required a coolant channel surface area to fueled volume ratio of approximately 15.0 in order to keep the centerline temperature below 3000 K. The configuration consisting of 10 mol.% Gd₂O₃ required a surface area to volume ratio of approximately 12.2 to cool the reactor to a peak temperature of 3000 K and had a total mass of 3200 kg and a thrust to weight ratio of 3.54. It is not known yet what concentration of Gd₂O₃ is required to maintain fuel stability at 3000 K; however, both reactors offer the potential for operations at 25,000 lb_∫ and and at a specific impulse which may range from 900 to 950 seconds.