A compact Gas Core Nuclear Rocket for space exploration

Abstract

The open cycle Gas Core Nuclear Rocket (GCR) possesses, in principle, outstanding propulsion characteristics that make it especially attractive for advanced space propulsion. With uranium as fuel and hydrogen as propellant, it can generate several thousand seconds of specific impulse and hundreds of kilonewtons of thrust. In its standard configuration, however, GCR is susceptible to hydrodynamic and acoustic instabilities, which if not adequately addressed, could lead to significant loss of fuel and severe limitation on its propulsion capabilities. In this paper we examine the potential utilization of americium in place of uranium, and study the effect of such fuel change on the size reduction of the system as well as its impact on the hydrodynamic stability question. We find that the same propulsion performance can be achieved at a comparable fuel density but with a radial size reduction of both core and moderator/reflector of about 70%, and a corresponding stabilizing effect on the KelvinHelmholtz instability which lies at the heart of turbulent mixing in this device. V'