Rapid measurements of 235U fission product isotope ratios using an online, high-pressure ion chromatography inductively coupled plasma mass spectrometry protocol with comparison to isotopic depletion models.

An automated online separation-direct analysis method, RAPID (rapid analysis of post-irradiation debris), has been developed for the measurement of the concentration and isotopic composition of over 40 elements down to the low-picogram level. Here we discuss the application of RAPID to irradiated highly-enriched uranium, demonstrating that it has the sensitivity required to achieve precise, low-level analyses of non-natural isotopes, even in the presence of a bulk uranium matrix. Isotopic ratios have been successfully measured at the low-picogram level, and the accuracy of these ratios was confirmed using an isotopic depletion and decay modeling software to within 1-2%. [ABSTRACT FROM AUTHOR]