Feasibility of Turbulent Vortex Containment in the Gaseous Fission Rocket

Abstract

A semi-empirical analysis was made of the feasibility of containing a gaseous nuclear fuel in a turbulent vortex flow. The analysis is an extension of the laminar diffusion analysis of Kerrebrock and Meghreblian, and includes the experimental information reported by Keyes, concerning the turbulence levels and vortex strengths attainable in jet-driven vortex tubes. It was assumed that the turbulent eddy diffusivity increases the diffusion due to concentration gradients, but has no effect on the diffusion due to pressure gradients. It followed from this assumption that the concentration profile of fissionable gas is broadened, but the position of the maximum concentration is the same as that predicted by the laminar analysis. From the experimental data and this assumption, it was deduced that satisfactory containment of plutonium, or one of its compounds, in hydrogen is possible for certain ranges of the vortex tangential and radial Reynolds numbers. The restrictions imposed on the system by the requirements for nuclear criticality and fission fragment absorption was examined. It was concluded that a vortex reactor providing a significant increase in gas enthalpy over that of the solid fuel nuclear rocket is feasible, however the total system mass is very large, and the thrust to weightmore » ratio is small. Several schemes for increasing the vortex strength, and reducing the turbulence level, are reviewed in the light of these results. Of these, the vortex matrix appears most promising. (auth)« less