Researchers have been looking into a mysterious cloud of radioactive matter that drifted across Europe in 2017. The scientists, who are based at the Vienna University of Technology, have been processing over 1,300 measurements (1,100 atmospheric and 200 deposition data points), which were taken from across Europe (22 countries in total), to try to pinpoint where the radioactive particles came from and what the implications are.
The radioactive material was due to human failings, as all major radioactive incidences ultimately are. The cloud was traced to nuclear reprocessing plant, located somewhere in the southern Urals. The most likely origin is the Russian nuclear facility Majak, although the Russian government have not publicly admitted anything.
The Mayak facility
The Mayak Production Association is one of the biggest nuclear facilities in the Russian Federation. It is located close to the towns of Ozyorsk and Novogornyj. The facility serves as a reprocessing site for spent nuclear fuel, producing tritium (a rare and radioactive isotope of hydrogen; along with along with deuterium it is used as a fuel for nuclear fusion reactions with applications in energy generation and weapons) and other radioisotopes.
Initial detection
Something strange began to be detected in September and October 2017, via a network of atmospheric monitoring sites across Europe (starting with an informal alert by an Italian laboratory). While this didn’t get much attention from the world’s media, it worried some scientists.
“We were stunned,” radioecologist Georg Steinhauser of Leibniz University Hannover in Germany told Science News. “We had never seen anything like this before.”
Further analysis
In terms of how the incident may have occurred, the researchers speculate that the cloud could have been released in what was a failed attempt to produce highly radioactive material, intended for an experiment on neutrinos (subatomic particles that are spit out in certain types of radioactive decay). This is speculated because the radioactive particles related to one element — ruthenium-106. It is this specificity that had the researchers connecting the detection to a specific type of experiment that may have been underway at the secure facility.
An alternative theory also presents itself: a satellite carrying a radionuclide battery could have burned up on re-entry – but this theory was dismissed by the research team. This is because the altitude measurements for the ruthenium were not consistent with this kind of event. Furthermore, the drifting plume effect is more in keeping with a leak from a processing plant or a reactor.
Health risks
In terms of the risk to public health, the news is good. The incident did not pose a health risk for the European population, based on the measurements assessed by the researchers.
Nevertheless, the scale of the release is significant. As Professor Steinhauser states: “We measured radioactive ruthenium-106. The measurements indicate the largest singular release of radioactivity from a civilian reprocessing plant.” The analysis shows a total release of about 250 to 400 terabecquerel of ruthenium-106.
Research paper
The findings are published in the journal Proceedings of the National Academy of Sciences. The research paper is titled “Airborne concentrations and chemical considerations of radioactive ruthenium from an undeclared major nuclear release in 2017.”
Essential Science
This article is part of Digital Journal’s regular Essential Science columns. Each week Tim Sandle explores a topical and important scientific issue. Last week we learned how neuroscience, in the form of special ‘mapping’ brain cells, is helping to drive improvements with the navigation systems of autonomous cars.
The week before, we looked at how variations to the gut microbiome are connected with anorexia, affecting how well a person can recover.
