Abstract: The energy of an X-ray beam and critical depth are selected to detect structural discontinuities in a material having an atomic number Z of 57 or greater. The critical depth is selected by adjusting the geometry of a collimator that blocks backscattered radiation so that backscattered X-ray originating from a depth less than the critical depth is not detected. Structures of Lanthanides and Actinides, including nuclear fuel rod materials, can be inspected for structural discontinuities such as gaps, cracks, and chipping employing the backscattered X-ray.

Abstract: A composite nuclear fuel pellet comprises a composite body including a UO2 matrix and a plurality of high aspect ratio particies dispersed therein, where the high aspect ratio particies have a thermal conductivity higher than that of the UO2 matrix. A method of making a composite nuclear fuel pellet includes combining UO2 powder with a predetermined amount of high aspect ratio particles to form a combined powder, the high aspect ratio particles having a thermal conductivity higher than that of the UO2 powder; mixing the combined powder in a solvent to disperse the high aspect ratio particles in the UO2 powder; evaporating the solvent to form a dry mixture comprising the high aspect ratio particles dispersed in the UO2 powder; pressing the dry mixture to form a green body; and sintering the green body to form the composite fuel pellet.

Abstract: The energy of an X-ray beam and critical depth are selected to detect structural discontinuities in a material having an atomic number Z of 57 or greater. The critical depth is selected by adjusting the geometry of a collimator that blocks backscattered radiation so that backscattered X-ray originating from a depth less than the critical depth is not detected. Structures of Lanthanides and Actinides, including nuclear fuel rod materials, can be inspected for structural discontinuities such as gaps, cracks, and chipping employing the backscattered X-ray.