Thermal Analysis of the SIRIUS3 Nuclear Propulsion Fuel Calibration Experiment

Abstract

To support long space missions, NASA is designing and testing different fuels for nuclear thermal propulsion. These designs encompass ceramic metallic fuels which are to be irradiated in the TREAT reactor to test the fuel's performance. This type of fuel is a ceramic fuel type dispersed in a metallic matrix. A set of experiments named the SIRIUS experiments are designed to test the performance of ceramic metallic fuels under conditions that are intended to be prototypical of mission conditions. These conditions include going from cold conditions ( 300K) to very hot conditions (2700K-3000K) in a very short amount of time (tens of seconds). The SIRIUS-3 experiment tests a column of 16 fuel specimens under irradiation conditions. For this paper, a Bison model is constructed and thermal analysis of the SIRIUS-3 experiment is performed. These analyses reveal the importance of different local experimental components to characterize the heat transport phenomena of the ceramic metallic fuel. This modeling and analysis also informs predictive modeling for future experiments such as the SIRIUS-2C and SIRIUS-5 tests, which will be a ceramic fuel type dispersed in a ceramic matrix.