Gas-cooled reactor power systems for space

The characteristics of six designs for power levels of 2, 10, and 20 MWe for operating time of 1 and 7 years are described. The operating conditions for these arbitrary designs were chosen to minimize system specific mass. The designs are based on recent work which benefits from earlier analyses of nuclear space power systems conducted at LLNL. Both gas and liquid cooled reactors had been considered. Pitts and Walter reported on the results of a detailed study of a 10 MWe lithium cooled reactor in a potassium Rankine system. Unpublished results of a computer analysis provide details of an argon cooled reactor in an argon Brayton system. The gas cooled reactor design was based on extensive development work on the 500 MWth reactor for the nuclear ramjet (Pluto) as described by Walter. The designs discussed here draw heavily on the Pluto project experience, which culminated in a successful full power ground test as reported by Reynolds. At higher power levels gas cooled reactors coupled with Brayton systems with advanced radiator designs becomes attractive.