| Abstract Scope |
Fission products generated during reactor operation alter the intrinsic properties of the fuel matrix, degrading thermal conductivity, thermal expansion behavior, and micromechanical performance. Historically, these effects have been described using empirical correlations, which often lack generalizability across fuel systems. In this study, we investigate the separate impacts of light and heavy fission product analogs on CeO₂ and UO₂ matrices by introducing yttrium (Y) and neodymium (Nd) as representative dopants. Sample designs were informed by trends predicted through a machine learning model, enabling targeted exploration of distinct degradation mechanisms. The samples were prepared by powder metallurgy followed by pressing and sintering under controlled conditions. Characterization was performed using electron microscopy with EDS, X-ray diffraction, calorimetry (Cp), laser flash analysis (LFA), and nanoindentation. Results reveal distinct impacts of light and heavy dopants on crystal structure and thermomechanical properties, providing experimental validation of model predictions and offering insights into dopant-specific degradation mechanisms based in elemental information. These findings support the development of more physics-informed, transferable models for fuel performance across a range of reactor conditions. |