Chemical reactivity of CVC and CVD SiC with UO₂at high temperatures

Two types of silicon carbide (SiC) synthesized using two different vapor deposition processes were embedded in UO₂ pellets and evaluated for their potential chemical reaction with UO₂. While minor reactivity between chemical-vapor-composited (CVC) SiC and UO₂ was observed at comparatively low temperatures of 1100 and 1300°C, chemical-vapor-deposited (CVD) SiC did not show any such reactivity. However, both CVD and CVC SiCs showed some reaction with UO₂ at a higher temperature (1500°C). Elemental maps supported by phase maps obtained using electron backscatter diffraction indicated that CVC SiC was more reactive than CVD SiC at 1500°C. Furthermore, this investigation indicated the formation of uranium carbides and uranium silicide chemical phases such as UC, USi₂, and U₃Si₂ as a result of SiC reaction with UO₂.