The Application of radiochronometry during the 4th collaborative materials exercise of the nuclear forensics international technical working group (ITWG)

Kristo, M. J.*; Williams, R.*; Gaffney, A. M.*; Kayzar-Boggs, T. M.*; Schorzman, K. C.*; Lagerkvist, P.*; Vesterlund, A.*; Ramebck, H.*; Nelwamondo, A. N.*; Kotze, D.*; Song, K.*; Lim, S. H.*; Han, S.-H.*; Lee, C.-G.*; Okubo, Ayako; Maloubier, D.*; Cardona, D.*; Samuleev, P.*; Dimayuga, I.*; Varga, Z.*; Wallenius, M.*; Mayer, K.*; Loi, E.*; Keegan, E.*; Harrison, J.*; Thiruvoth, S.*; Stanley, F. E.*; Spencer, K. J.*; Tandon, L.*

In a recent international exercise, 10 international nuclear forensics laboratories successfully performed radiochronometry on three low enriched uranium oxide samples, providing 12 analytical results using three different parent-daughter pairs serving as independent chronometers. The vast majority of the results were consistent with one another and consistent with the known processing history of the materials. In general, for these particular samples, mass spectrometry gave more accurate and more precise analytical results than decay counting measurements. In addition, the concordance of the U-Pa and U-Th chronometers confirmed the validity of the age dating assumptions, increasing confidence in the resulting conclusions.