In early October, radiation monitors around Europe began detecting a puzzling plume of radioactive particles over the continent. Nearly two months later, no one has claimed responsibility for the leak, but experts suspect it came from Russia.
Specifically, the preponderance of evidence points to an area around the Ural Mountains near the Russia-Kazakhstan border as the source of the emissions.?
The radioactive isotope detected at unusually high levels is Ruthenium-106. Ruthenium is a by-product of a radioactive material used in medicine, molybdenum-99, according to NPR. These days, radiation detection monitors are extremely sensitive, so even small leaks are eventually exposed.
"You can’t hide these things anymore, so you might as well notify the world as soon as it happens,” said Edwin Lyman, a senior scientist and nuclear power safety expert at The Global Security Program, in an interview.
However, neither Russia, nor anyone else, has fessed up to the leak.
The radiation, which stretched from Russia all the way to the United Kingdom and Spain, generally decreases in concentration the farther west it gets from the Russia-Kazakhstan border.
"I was in that region a few months ago," said Lyman. "I'm glad it didn’t happen while I was there."
Although Lyman notes "it's getting harder and harder for nuclear operators to conceal mishaps of radioactive materials," this doesn't mean it's easy to locate the specific source of leaked radiation. Especially in this case.
"It’s a forensic puzzle," Lyman said.
From the detectors placed around Europe, scientists know the release was pretty small. But what is rare, Lyman explained, is that just one type of radioactive isotope was picked up.?
If there was a leak from a massive nuclear energy facility, for instance, a variety of heavier radioactive particles would have swirled into the air and fallen to the ground around the area. That was the case as a result of the Chernobyl nuclear disaster in Ukraine in 1986, for example.
In this case, it was just Ruthenium-106, leading experts to suspect it came from a facility concentrating this specific radioactive material for an industrial or medical purpose. In the area with the highest detected concentrations of Ruthenium-106, near the Ural mountains, lies Russia's Research Institute of Nuclear Reactors (RIAR).?
A RIAR spokesperson, however, told NPR that in the last six months "no incidents had occurred at the facility and that 'Ruthenium was not produced in that period.'"
Further confusing matters, Russia is home to many nuclear facilities, including an assortment in the suspected source region. One of the more well-known facilities, according to Lyman, is the Mayak Production Association, which once refined plutonium for use in atomic bombs. Today, Mayak reprocesses spent nuclear fuel.?
Whatever the source, Lyman says this radioactive event, while likely not being significant enough to harm people (unless there was a "hot spot" of accumulated particles close to the leak), serves as "a cautionary tale." If a greater leak were to occur, the public should be notified promptly, so they can take shelter and protect their food and water supplies.?
In this case, no notice of the leak was given. It was detected, and with modern instruments, it will always be detected, eventually.?
"You can't hide," said Lyman. "It's better to chartph.come clean."