Some results of determining the source and reasons for the appearance of 106Ru in Russia in September-October 2017

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

“…Currently, no country has assumed responsibility for this considerable release, which is likely the single-largest accidental release from civilian nuclear reprocessing 4 . Despite a large number of meteorological indications 3,[5][6][7][8] , Russian authorities and institutions have repeatedly denied any involvement of the Mayak facility in the release [9][10][11] . In their official statement 9 , the Rosatom State Nuclear Energy Corporation emphasized that there were not any incidents at any of the Rosatom sites during the period of September-October 2017.…”

Identification of a chemical fingerprint linking the undeclared 2017 release of 106 Ru to advanced nuclear fuel reprocessing

“…To address the location of the 106 Ru source, recent reports have used dispersion modeling and field measurements of 106 Ru concentration (airborne and ground deposition) to demonstrate an origin in the Southern Urals of Russia, in the area of the Mayak industrial complex ( 1 , 5 – 9 ). A long history of nuclear-related activities in this area, combined with the radiopurity of the field observations and the detection of the short-lived 103 Ru, lends credence to the scenario of an accidental release during nuclear fuel reprocessing and serves to dispel some persistent theories on the origin of the release (e.g., nuclear reactor accident, downed radioisotope thermoelectric generator satellite, volatilized medical sources, etc.)…”

Atmospheric contamination with ruthenium-106 detected in Europe in Autumn 2017

“…Authors from the Federal Service for Hydrometeorology and Environmental Monitoring of Russia ('Roshydromet') would seem to have cast doubt on this official Russian stance. In two journal papers published in English in early 2019 [10,11] the authors point out that Roshydromet monitoring stations detected 'high concentrations' of 106 Ru in the Southern Urals in late-September 2017, and that the levels of 106 Ru reported in Europe 'are caused by the release on September 25-26'. Moreover, 'The most probable version of Ru-106 in flow to the atmosphere from the ground-based source in the South or Central Urals is substantiated'.…”