2017 | AFC ACCOMPLISHMENTS 106 allow characterization of features hitherto hidden from conventional characterization methods. Accomplishments: We demonstrated energy-resolved neutron imaging and neutron diffrac- tion characterization, successfully demonstrated to oxide, nitride, silicide fuels in the past, also to transmuta- tion fuels. For this research, four slugs of metallic fuels with a nominal composition of U-20Pu-10Zr (wt. %) were produced at INL (R. Fielding) and loaded in two rodlet/capsule assemblies. Material in one capsule also contained Am (~2 wt. %) and Np (~3 wt. %).Tomographic imaging and diffraction measurements were performed to characterize these samples at the Flight-Path 5 and High Pressure Preferred Orientation (HIPPO) beam lines at LANSCE/ LANL. Due to the presence of Pu, the penetration of the material by thermal neutrons is limited to ~1.3 mm (e-1 penetration depth) and since diffracted neutrons are also attenuated, the volume probed by thermal neutrons is only a layer of ~650 micrometer. However, access to transmission data in the epi-thermal neutron range, provided by the pulsed neutron spallation source at LANSCE and captured with a 512x512 pixel time-of-flight imaging detector, allows characterization of sample dimen- sions, cracks, chemical and isotopic inhomogeneities for these samples. Several inclusion and shape irregulari- ties were identified with this unique tool.The diffraction data complements these results, but cannot provide bulk characterization as the penetration of thermal neutrons, suitable for diffrac- tion, is limited to the outer layers of the material.The bulk composition described by partial densities of the main isotopes 237Np, 238U, 239Pu, 240Pu, and 242Am agrees to better than 0.1 g/cc with the partial densi- ties determined by mass spectrometry except for 238U, which was overes- timated.These findings underline the substantial benefits of pulsed neutrons over a continuous neutron source, such as a reactor, or hard X-rays Energy-resolved neutron imaging was applied to U-20Pu- 10Zr fuel slugs to demonstrate the characterization of fuel forms opaque to X-rays and thermal neutrons as well as 3D measurements of isotope densities with this technique and producing for the first time XRF-like isotope maps obtained non-destructively for the bulk of the sample.