Demonstration of Near Field High Energy X-Ray Diffraction Microscopy on High-Z Ceramic Nuclear Fuel Material

Near-field high energy x-ray diffraction microscopy (nf-HEDM) and high energy x-ray micro-tomography (mu T) have been utilized to characterize the pore structure and grain morphology in sintered ceramic UO2 nuclear fuel material. mu T successfully images pores to 2-3 mu m diameters and is analyzed to produce a pore size distribution. It is apparent that the largest number of pores and pore volume in the sintered ceramic are below the current resolution of the technique, which might be more appropriate to image cracks in the same ceramics. Grain orientation maps of slices determined by nf-HEDM at 25 pm intervals are presented and analyzed in terms of grain boundary misorientation angle. The benefit of these two techniques is that they are non-destructive and thus could be performed before and after processes (such as time at temperature or in-reactor) or even in-situ.