Abstract and subjects
In nuclear forensic analyses, measurements of actinideelementsin a sample can assist with identifying interdicted or unknown materials.While these radiochemical signatures have been extensively investigatedin uranium materials, less is known about bulk neptunium samples.This paper describes the measurement of trace actinide concentrationsand isotopic profiles in a Np-237 oxide sample. Uranium,plutonium, americium, and curium concentrations and isotopic profilesin the sample were determined and deemed potentially useful for distinguishingdifferent sources of Np-237. Several different potentialradiochronometry systems were also investigated; discordant resultsindicate that the Np sample was never completely purified of otheractinide elements, or that subsequent contamination of the sampleoccurred. Few prior studies of neptunium materials have been reported,and these data suggest that trace actinide constituents could provideunique signatures to identify material out of regulatory control.