In 2017, a cloud of ruthenium-106 particles set off radiation detectors across Europe. Although scientists gradually honed in on the geographic source, attempts to confirm it have been frustrated. Careful analysis of the cloud’s composition has now indicated the source was a civilian site rather than a military one. In Central and Western Europe, the late 2017 radiation spike was not high enough above background levels to pose a threat to human life. Closer to the source, however, things could have been quite different, sparking a hurried search to identify the origin of the emissions. Equally important is the question of what triggered the release, lest something larger occur in the future. From the start, suspicion turned to Russia based on the general direction and a poor nuclear safety record. Subsequent research narrowed the location down to the southern Urals. The refusal of Russian authorities to acknowledge responsibility, let alone reveal the source, inspired speculation that the origins might lie in a secret military facility.
IFL Science 15th June 2020 read more »