A neutronic study of the open-cycle gas core nuclear

The neutronic cliaractcristics of tlic open-cyclc Gas Corc Nuclear Rockct (GCR) are studied. In tlic first portion of the paper, a parametric analysis is pcrforincd which investigates how kcK varies as a function of sevcral dcsign parameters. The paranictcrs varied includc the temperature and composition of tlic fucl and propellant, :IS ~vcll as the inodcrator thickncss. In tlic second portion of tlic paper, the ncutronic model is coupled with a tlicriiial-hydraulic iiiodcl that solves the 2-D steady statc conservation equations of mass, species, axial iiionicntum, radial momentum, aiid energy. The neutronic solution of one particular design is studied in dctail, including the spatial variation of powcr density, neutron flux, and neutron cnergy spectra. Finally, tlic effect of using altcrnate fiiels and propellants is cxamincd.