Several days ago, we published our first blog post about the notable release of Ruthenium-106 that was detected in Europe in late September-early October of this year. As we noted, detections of Ru-106 were confirmed by over 30 countries, and careful analyses performed independently by the national laboratories of France, Germany, and the Czech Republic all pointed to the southern Urals as the likely origin of the release. From the outset, the accident-prone nuclear processing facility at Mayak, in the Chelyabinsk region in the southern Urals, was considered a prime suspect. But Russian authorities vehemently denied that any unusual levels of Ru-106 had been detected in that country, or that Russia was in any way responsible.
Yesterday Russia came clean. Sort of.
Specifically, the Russian meteorology service Rosgidromet issued a statement (in Russian) that levels of Ru-106 up to 986 times the normal background level had been detected in that country in September (helpful English-language news articles here and here). The highest levels were detected in Argayash, about 20km from Mayak. An 11-page Russian-language bulletin containing measurements from dozens of locations in Russia in September surfaced online shortly afterward.
Nadezhda Kutepova, a Russian activist who has clashed with authorities because of her work on behalf of workers and the public in Mayak, was forced to flee to France in 2015; she issued a detailed statement from Paris on November 21st in which she gave plausible reasons why the Ru-106 release was likely due to a malfunctioning nuclear waste glassification system at Mayak. Spokesmen from Mayak, however, continue to deny that the facility is in any way responsible. No other nuclear-related facility in Russia has claimed responsibility yet either.
It is difficult to accurately gauge the seriousness of possible health consequences of this release without more detailed information from the site of the accident. IRSN and BfS had estimated that the total release was between 100-300 terabecquerels, which is considerable. Experts have commented privately that this could place the accident at Level 4 on the INES scale, i.e, an “accident with local consequences” (both Fukushma and Chernobyl were INES Level 7).
Similarly, only very rough dose calculations can be made at present, without access to volumeric air measurements that would give a better idea of how much might have been inhaled at various points. Many experts have noted the fact that the normal background level of Ru-106 is nearly zero, so even a 1000-times increase correlates to a relatively small amount. Only extremely small trace quantities were detected outside of Russia. The half-life of Ru106, a beta-emitter, is 374 days, which means it will persist in the environment for many years, however. In its statement in early November, IRSN said that had an accident of this scale happened in France, it would have prompted protective measures to the public and to the food supply. But so far in Russia, there is no indication that any action was taken, nor any information provided to the public until yesterday except denials. Despite the important data released by Rosgidromet yesterday, the coverup continues.