2, Idaho National Laboratory, Idaho Falls, Idaho, United States
The detailed and quantitative understanding of mesoscale in-reactor degradation behavior of nuclear fuels is of critical importance as it is the evolution of the microstructure that has the most profound impact on bulk properties and in-reactor performance of nuclear fuels and thus on the development of next generation reactor systems. In this contribution, we will discuss the recent progress made in microstructural and microchemical characterization of different fuel systems, including mixed oxide (MOX), U-Mo, and U-Pu-Zr. The value of 3D techniques, such as focused ion beam (FIB) nano-tomography and atom probe tomography (APT), in nuclear fuels research will be demonstrated and the challenges in interpreting 3D tomography results on irradiated fuels addressed. In addition, microstructure-property relationship will be discussed and experimental data will be linked to ongoing modeling efforts.