Multiplatform Microanalysis of Actinide Materials for Nuclear Forensics

When nuclear material is interdicted, nuclear forensics capabilities are called on to determine as much information as possible about the material’s origin, processing, time since processing, and pathways so that authorities can efficiently determine the perpetrator. The analysis of critical material information requires accurate identification of distinguishing material characteristics. Key material signatures, such as morphological and chemical variations, that pinpoint recent provenance can reside within bulk nuclear material. Conventional analysis using bulk nuclear material provides an overall analytical value, but a typical nuclear material is inhomogeneous, thus the critical forensic signatures may be obscured and invariably display average characteristics from local variations of morphological and chemical properties. In this paper, we present our multiplatform microanalysis with focused ion beam-scanning electron microscopy (FIB-SEM), three-dimensional (3D) spatial modeling, transmission electron microscopy (TEM), and synchrotron-based chemical microanalysis on plutonium (Pu) and uranium (U) materials. Our work shows the internal morphological and chemical variation in host nuclear materials provide valuable information about the material’s forensic signatures. We identified that internal microscopic features containing trace elements or chemical are attributable to their origin, processing, and environmental exposures.<br/> <br/>Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-828231