Nuclear forensic analysis of a non-traditional actinide sample

Nuclear forensic publications, performance tests, and research and development efforts typically target the bulk global inventory of intentionally safeguarded materials, such as plutonium (Pu) and uranium (U). Other materials, such as neptunium (Np), pose a nuclear security risk as well. Trafficking leading to recovery of an interdicted Np sample is a realistic concern especially for materials originating in countries that reprocesses fuel. Using complementary forensic methods, potential signatures for an unknown Np oxide sample were investigated. Measurement results were assessed against published Np processes to present hypotheses as to the original intended use, method of production, and origin for this Np oxide. [Display omitted] •Full forensic characterization of a neptunium oxide sample.•Successful assay of neptunium oxide using controlled potential coulometry despite lack of available standards.•Chronometry of sample completed showing young model age.•Interesting Pu isotopic composition narrows potential site of origin.