|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Materials and Fuels for the Current and Advanced Nuclear Reactors VII
||Probing Local Disorder in Ln-UO2 (Ln = Y, Nd, La) and UO2+x Systems
||Raul I Palomares, Sarah Finkeldei, Lei Zhang, Tiankai Yao, Felix Brandt, Alexandra Navrotsky, Jie Lian, Maik Lang
|On-Site Speaker (Planned)
UO2-based nuclear fuels are shown to exhibit increasing hyper-stoichiometry and incorporation of rare earth elements at very high burn-ups. These changes can significantly influence, for example, oxygen diffusivity and thermodynamic properties. In this study, neutron total scattering was employed to investigate the impact of these effects on structural stability and short range atomic ordering. Total scattering analysis shows that small deviations from ideal stoichiometry and composition yield minute changes in both the average and short-range structures of the materials. Detailed pair distribution function analysis reveals that the small changes are adequately fit by modeling very short (~0.07 Ć) atomic relaxations. Interestingly, the results show that the effects of these short-range relaxations extend into the intermediate-range structure. Efforts are now underway to develop more holistic representations for these systems via the incorporation of point defects and nano-domains into models. Preliminary results from these analyses will be discussed.
||Planned: Supplemental Proceedings volume