Power plant explosion in Russia may have triggered 2017 radioactive cloud

30 Jul 2019

Image: © Sergey Kamshylin/Stock.adobe.com

Scientists have traced an unnatural nuclear leak detected in 2017 to an area in Russia, suggesting a possible unreported nuclear plant accident.

Not long after the tragedy of the Chernobyl event has been refreshed in the minds of TV viewers, an international team of scientists has suggested that a possible explosion in a nuclear power plant in 2017 resulted in a radioactive cloud spreading across Europe.

According to Physics World, a botched production of a powerful neutrino source likely created the radioactive cloud in autumn of that year, spreading westward across much of the continent. At the time, aerosols containing the element ruthenium-106, which is not found in nature, were detected as far west as Norway by a string of radiation detection stations built after the Chernobyl disaster in 1986.

While not in concentrations that would pose a risk to human health, the origin of the cloud remained a mystery, until now.

Publishing to the Proceedings of the National Academy of Sciences, the research team traced it back to an explosion at Russia’s Mayak nuclear fuel reprocessing plant. It said that it is likely the leak occurred as workers were attempting to produce an intense source of the element cerium-144 for an Italian neutrino experiment.

A crashed nuclear satellite?

The plant first came under suspicion in October 2017 after France’s institute of radioprotection and nuclear security pinpointed the cloud’s origin to the southern Urals, which was confirmed by Russian meteorology agency Roshydromet.

However, Russian officials denied that Mayak was the source of the leak, despite it being the only plant in the region capable of producing cerium-144. Instead, officially, it was said that the release was from the disintegration of a satellite that had returned to Earth.

A panel was established to investigate the theories, comprising Russian and non-Russian scientists who convened in January and April of last year. However, Russian scientists argued that soil measurements taken around the Mayak plant were not brought into consideration as they showed “low levels of contamination”.

Yet according to Georg Steinhauser of Leibniz Universität in Hanover, Germany, he and his colleagues dismissed alternative causes proposed by the panel, arguing that ruthenium-106 couldn’t have been released by a nuclear satellite. This is because its half-life – lasting just 372 days – would be too short to power a satellite for a long mission, as well as the fact that no satellites were reported missing at the time of the radioactive cloud release.

Speculating, Steinhauser said if an explosion did occur at the Mayak plant, it is possible that workers there could have been killed. “For a worker who is standing in the plume, that would mean very, very unpleasant doses,” he said.

Along with Chernobyl, Mayak is known as the site of one of the worst nuclear disasters in history. The plant – built in the 1940s to support the Soviet Union’s atomic bomb programme – experienced an explosion in a cooling system used for handling thousands of tonnes of nuclear waste in 1957. The resulting explosion saw as many as 55 people dying as a direct result of the explosion and almost 500,000 people exposed to radiation.

Colm Gorey was a senior journalist with Silicon Republic