Nuclear forensic signatures of UO2 fuel pellets for differentiation and provenance determination illustrated using synthetic database

Abstract

This paper presents a comprehensive nuclear forensics signatures analysis of UO2 fuel pellets, allowing their provenance to specific manufacturers. The study is based on a synthetic database designed for the 4th international Galaxy Serpent exercise circulation, which mimics real fuel pellet characteristics. The scenario of the exercise is completely fictional, including the data used and manufacturers' names, locations, etc. The signatures investigated include chemical form, pellet dimensions, equivalent boron content, Gd additive, impurities distribution, and isotopic composition. The consistency levels of the results, which determine the confidence in the provenance process, were divided into four levels due to the varying resolving power of the signatures. The paper emphasizes the importance of a graphical representation of the results to simplify interpreting multi-degree-of-freedom data, typical to nuclear forensics investigations, including the amalgamation of quantitative and qualitative information. The analysis connects 11 orphan pellets and a single UO2 powder to five manufacturers. The presented methodology offers a straightforward approach to data interpretation in nuclear forensic investigations and highlights the need for continued research and development in this field.