A mysterious cloud of radioactivity has been detected drifting over Europe in the past two months. Monitoring stations associated with the Comprehensive Nuclear Test Ban Treaty Organization and with the France-based Radioprotection and Nuclear Safety Institute (IRSN) detected unusually large amounts of ruthenium 106 in the atmosphere. International monitors said the cloud was due to a probably accidental release that most likely originated in southern Russia, near the border with Kazakhstan, between the Volga River and the Ural Mountains.
When the radioactivity was first detected, in Italy on 3 October, IRSN quickly pulled data from its network, and found especially high concentrations recorded in monitoring sites in Mediterranean cities such as Nice, Toulon, and Ajaccio on the island of Corsica. The concentrations were highest between 3 and 6 October, according to the IRSN, and have been imperceptible in France since 13 October. The data suggested a release some time in the last week of September.
Using simulations of a release that incorporated weather reports and drift patterns, the IRSN said that “the most plausible zone of release lies between the Volga and the Urals, without it being possible, with the available data, to specify the exact location of the point of release.” The Institute produced a map dividing the region of the drift into zones, and indicating the relative plausibility that the cloud could have originated in each zone.
Jean-Christophe Gariel, director for health at the IRSN, said the level of radioactivity detected in France was relatively small, and presented no serious threat to health. For that amount to have reached France, however, he suggested that it must have been a large release which would have presented health risks in the immediate area in Russia. The IRSN statement said that had a similar accident occurred in France, authorities would have evacuated the area of “a radius of a few kilometers,” and would have considered food products unsafe in an area for “a few tens of kilometers” around the source.
The Mayak plant is no stranger to nuclear accidents, having been the site of over 30 accidents
Because only ruthenium 106 was detected, and there were no other radionuclides present, IRSN analysts have ruled out a nuclear power plant disaster. Ruthenium 106 is an isotope that does not occur in nature, but is a by-product of nuclear reprocessing or as a component of producing radioactive materials for medical purposes.
There are several nuclear reprocessing plants in the region indicated by the IRSN analysis, among them an infamous facility called the Mayak Production Association, a Cold War-era facility that specializes in turning spent nuclear energy fuel into weapons-grade nuclear material. Although the exact origin of the release cannot be determined, the Mayak plant is no stranger to nuclear accidents, having been the site of over 30 accidents and releases that are publicly documented. One of them, known as the Kyshtym disaster, is considered the third worst nuclear accident in history, exceeded in severity only by Chernobyl and Fukushima.
In that 1957 incident, the failure of a cooling system for a storage tank caused a non-nuclear explosion that in turn caused the release of nuclear isotopes. Because the Soviet Union covered up the incident, and denied for 30 years that it took place, estimates of dead and injured from radiation poisoning and long-term health effects are uncertain, but they range from several dozen to hundreds killed, and thousands injured.
Although Russia is much more transparent now than the old Soviet Union, it is nonetheless troubling that whatever happened in September was not reported by Russian authorities. If the ruthenium 106 was released because of yet another accident at the Mayak Production Association, then this is an indication of continued instability of operations and poor management at a historically unsafe nuclear processing facility. It could easily be a leading indicator of worse accidents in the making, that could be prevented by a thorough inspection and overhauling of management and safety protocols.
Even another release of ruthenium 106 is not without its dangers. Although the amounts detected by French monitoring stations were low enough to pose little threat to health, ruthenium in any form is toxic, and 106 is considered a highly carcinogenic radionuclide.
Given the many problems Russia is causing and exacerbating in the world, this may seem inconsequential, but it should not be allowed to pass unnoticed. Russia’s cavalier attitude toward nuclear safety has damaged its neighbors before. We should consider this relatively benign accident a warning bell, and ask Putin to explain what happened, and what steps have been taken to prevent its recurrence.