| Abstract Scope |
Uranium nitride offers high uranium density and thermal conductivity, but its path toward qualification requires irradiation data that resolve how fabrication-driven variability affects performance. ROADRUNNER—Research On ADvancing the peRformance of UraNium Nitrides in Extreme enviRonments—is an NSUF-enabled MiniFuel irradiation campaign designed to probe these relationships across controlled variations in density, impurity content, temperature, and burnup. This talk will describe the motivation, experimental design, and pre-irradiation baseline characterization supporting insertion of LANL+UTSA fabricated UN specimens into HFIR using an established accelerated burnup testing platform. By pairing targeted fabrication with dimensional, density, microstructural, thermal, and XCT characterization, ROADRUNNER creates a framework for connecting processing history and sample quality to in-reactor response. The campaign is intended to generate mechanistic data relevant to fission gas behavior, microstructural evolution, and performance model validation, while demonstrating how user-facility access can bridge fundamental fuel science and qualification-relevant irradiation testing for advanced reactor concepts under representative service conditions. |