Non-natural ruthenium isotope ratios of the undeclared 2017 atmospheric release consistent with civilian nuclear activities

摘要

Isotope ratios for Ru/ Ru, Ru/ Ru, Ru/ Ru, and Ru/ Ru. The Ru containing sample air filter of the 2017 atmospheric release of nuclear Ru (red diamond) exhibits distinctly non-natural Ru isotope ratios. Four reference air filter samples (black circles) collected from 2015 to 2018 have similar Ru isotope ratios that agree with natural Ru and are indicative of the typical background Ru collected by air filters in Vienna. The gray bars represent the standard deviation (2 s.d.) on the average isotope ratios of the four reference filters and are treated as the external reproducibility of the measurements. Error bars on individual samples correspond to 2 s.e. (  n ≥ 3) of measurements and are, if not visible, smaller than the symbols.