Enrichment of Chromium at Grain Boundaries in Chromia Doped UO2

Assessment of grain boundaries in chromia (Cr2O3) doped fuels has been carried out using high resolution transmission electron microscopy to assess the structure compared to undoped fuel produced via the same process. Chemical analysis of the grain boundary was carried out using Energy Dispersive X-ray Spectroscopy (EDS). It was shown that a relatively disordered phase is formed along the grain boundaries in the doped fuel and that they were chemically enriched in chromium. This has implications for the prediction and understanding of fuel manufacture and in-reactor behaviour as many processes are highly dependant on grain boundary mechanisms.