2018 | AFC ACCOMPLISHMENTS 105 The dimensional change of the fuel as a result of irradiation also gives insight into the fission product behavior.A MATLAB program for determining the post-irradiation volume of the fuel specimens using x-ray computed tomography (XCT) tomograph images has been created and validated using standards of similar size to the MiniFuel specimens. Figure 3 shows the cross-section of a uranium nitride TRISO tomograph and a tungsten carbide kernel tomograph with coloration of segmented layers, which is used in the volumetric analysis. The methods for microstructural characterization of MiniFuel are based on past experience with particle fuel development at ORNL and include mounting microspheres for polishing in-cell and subsequent analysis with a variety of electron microscopes located at IFEL and the Low Activation Materials Development and Analysis (LAMDA) laboratory.These methods are directly applicable for use with the small geometries expected for Mini- Fuel irradiations. All methods have been demonstrated and are ready to be implemented in-cell and used on the first set of MiniFuel specimens, which will provide process experience for further development. Future work on post-irradiation examination methods for MiniFuel includes the development of additional methods to analyze thermophysical and mechanical properties. Figure 3. Cross-section of an un- irradiated UN TRISO tomograph (left) and cross-section of a tungsten carbide standard tomograph (right) with coloration of segmented layers.