News Release

Tracking the source of radioactive ruthenium

Peer-Reviewed Publication

Proceedings of the National Academy of Sciences

A study attempts to identify the source and circumstances of an undeclared radioisotope release. In October 2017, significant atmospheric levels of the radioactive isotope ruthenium 106 (106Ru) were detected in many countries throughout Europe. The detected levels, although too low to endanger human or environmental health, suggested a sizeable release of 106Ru not associated with declared nuclear accidents. Olivier Masson, George Steinhauser, and colleagues compiled more than 1,100 atmospheric measurements and 200 deposition measurements of 106Ru levels from across Eurasia. The vertical distribution of 106Ru was inconsistent with an alleged disintegration of a radioisotope-carrying satellite. The highest 106Ru levels were detected over Romania. However, the detections occurred at multiple locations throughout the country simultaneously, suggesting that the 106Ru plume had widened to the width of Romania by that point, and therefore originated a considerable distance away. Models of air mass movements in the days preceding detection and 106Ru deposition patterns were consistent with a release from the Mayak nuclear complex in the Southern Urals of Russia. The 103Ru /106Ru ratio, combined with the absence of other radioisotopes, suggests that the 106Ru came from reprocessing of approximately 2-year-old spent nuclear fuel. According to the authors, the release might have occurred in conjunction with production of a cerium-144 source for a neutrino experiment.

Article #19-07571: "Airborne concentrations and chemical considerations of radioactive ruthenium from an undeclared major nuclear release in 2017," by Olivier Masson et al.

MEDIA CONTACT: Georg Steinhauser, Leibniz Universität Hanover, GERMANY; tel: +49-511-762-3311; e-mail:


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