Gas Core Reactors for Deep Space Propulsion

Abstract

The operation of a nuclear power station powering Deep Space transport is presented in the paper. The power station consists of a Gas Core Reactor (GCR) with magnetohydrodynamic (MHD) generator. A new model of gas core reactor which has advantages by comparison with known models is suggested. It is shown that $200\ ton$ system would generate $200\ MW$ electricity. The gas core reactor consists of a spherical cavity of $1\ m$ to $1.5\ m$ radius surrounded by a $50\ cm$ thick liquid beryllium reflector within molybdenum--92 container. The fuel consists of $^{235}$UF$_4$, KF, and K. It is demonstrated that such power station will work for gaseous fuel pressures of $50\ atm$ to $100\ atm$. The Monte-Carlo simulations describing paths of thousands of neutrons are performed. These simulations yield neutronic results, i.e. the fractions of neutrons causing fission, being absorbed by moderator, and escaping the reactor. From this information one can calculate minimum needed pressure inside the reactor, the reactor size, and moderator thickness. The conductivity of superheated fuel depending on temperature and pressure is also calculated. It is concluded that space propulsion is the best use of uranium resources.