A HIGH TEMPERATURE OUT-OF-PILE EXPERIMENT FOR TESTING NUCLEAR THERMAL PROPULSION SURROGATE FUELS.

Nuclear Thermal Propulsion derives power from fission to heat hydrogen gas to produce thrust for propulsion. This technology dates to the 1950’s and the early days of the space race between the United States and the Soviet Union, but much more development is required to bring it into a technologically mature state. The fuel and reactor component qualification remain incomplete and are crucial to developing engine designs that can reliably facilitate interplanetary space travel. This work describes a Nuclear Thermal Propulsion fuel test strategy that integrates nonradiological out-of-pile tests and in-pile radiation tests that utilize sub-scale specimen geometries to subject fuel materials to Nuclear Thermal Propulsion conditions. Earlier Nuclear Thermal Propulsion development efforts relied on full-scale prototype reactor tests to qualify fuels and reactor designs. The approach developed here reduces risk of the fuel qualification process. This work includes the design, modeling, and testing of an experiment called “OUTSET” that exposes candidate fuel and reactor component materials to 2,300°C, which is typical of Nuclear Thermal Propulsion service conditions. The design requirements for OUTSET are established, construction & testing details for the experiment are described, experiment transient temperature results from thermocouples, short wave infrared camera response, and melt wire are reported. A thermal model for OUTSET is developed using ANSYS and data from experiments are used to validate this model following the American Society for Mechanical Engineers consensus standard Verification &Validation -20.