TECHNOLOGY DEVELOPMENT PROGRAM FOR AN ADVANCED POTASSIUM RANKINE POWER CONVERSION SYSTEM COMPATIBLE WITH SEVERAL SPACE REACTOR DESIGNS

The major goal of space reactor power system designers is to increase the specific power (kWe/kg) of the overall reactor power system. During the early days of the U.S. space power program, Rankine cycle power conversion technology was vigorously pursued as an approach for achieving extremely favorable specific powers — particularly for system power levels on the order of 100 kWe and larger. As a result, liquid‐metal Rankine cycle power conversion technology is relatively mature (compared to other dynamic power conversion technologies), with in‐space flight demonstration being the principal remaining impediment to its near‐term application. The unique technology issue associated with a space‐based Rankine system is the control and management of two‐phase liquids. While many aspects of two‐phase management have been demonstrated for short periods of time in zero‐gravity with water and organic working fluids, the demonstration of liquid‐metal two‐phase systems in space remains the fundamental obstacle to it...