| Tri-uranium di-silicide (U3Si2) is a candidate for use in accident tolerant fuel systems because of its higher thermal conductivity at elevated temperatures and higher fissile density - relative to the current standard light water reactor (LWR) fuel, UO2. Advanced steels, including FeCrAl, for its superior mechanical and thermal properties and oxidation resistance, are being considered as an alternative to the standard LWR cladding, Zircalloy. The interaction between U3Si2 and FeCrAl was investigated in this study. U3Si2 pellets were fabricated and placed in diffusion couples with FeCrAl. Individual tests were ran at temperatures ranging from 500 °C to 1000 °C for 30 hours (h) and 100 h. The interdiffusion was analyzed with an optical microscope, scanning electron microscope (SEM), and transmission electron microscope (TEM) equipped with an energy-dispersive X-ray spectroscopy (EDS) system. Distinct U2Fe3Si/UFe2 and UFeSi layers were observed at the material interface. U diffused far into the FeCrAl and Fe diffused far into the U3Si2 in the higher temperature tests. |