DETAILED CHEMICAL CHARACTERIZATION OF URANINITE: FORENSIC APPLICATIONS

Uranium ores occur in a wide variety of geological settings, including high temperature magmatic, metamorphic, and low-temperature sedimentary deposits. UO₂, the most essential raw material for nuclear fuel preparation, can incorporate variable quantities of trace elements during crystallization, thus its chemical signature will reflect the environment of formation. Samples of UO₂ investigated here were selected from “The Rod Ewing mineral collection” housed at the University of Notre Dame. In this work, micro-X-ray fluorescence, electron microprobe, and laser ablation- inductively coupled plasma mass spectrometry (LA-ICPMS) analyses were carried out on individual uraninite grains from various localities within North America; these include samples from North Carolina, New Hampshire, Colorado, Utah, Wyoming, Arizona, and New Mexico. Detailed chemical characterization (major, minor, and trace elements) of uraninite sampleswere conducted in relation to nuclear forensics applications. Of particular interest are the rare earth element (REE) abundances of uranium oxide due to their low sensitivity to redox changes, and their relative ease of substitution for uranium because of similar ionic radii.