But the canisters are turning up all around the old USSR. After being prodded by the IAEA, Russia’s Ministry of Atomic Energy gradually divulged that in Soviet times a factory in Estonia churned out at least 900 of the generators, including some models that are five times more radioactive than the units recovered in Georgia. No more than a couple dozen of the generators have been accounted for, says González, adding that the IAEA’s efforts to track down the missing generators are hampered by a legacy of lost records and even theft. Because the generators once also provided electricity for lighthouses along the Arctic coast, from the Baltic to the Bering Strait, Russia is working with the Norwegian Radiation Protection Authority to salvage radiothermal generators in the Murmansk region and ship them to a Russian nuclear site for storage.
Inspired by the rad rangers’ successes in Georgia, government and IAEA officials are stepping up the search for renegade radiation sources in other former Soviet nations. The United States, Russia and the IAEA teamed up in Moldova last December to capture such materials, and the IAEA sent technicians for the first time into Tajikistan in central Asia. “I used to say that we were seeing the tip of the iceberg,” says González. But in the past year, he says, “more and more of that iceberg has come into the open.”
Still, the most insidious orphaned radioactive source came to light only early last year when the IAEA learned of an experimental agricultural project called Gamma Kolos. (Kolos, a Russian word, refers to grain.) In the Soviet-era program, which started in the 1970s but was abandoned, tractors fitted with containers of cesium 137 (and lead shielding to protect the driver) irradiated wheat seeds before sowing them, in an attempt to induce beneficial mutations in the crops. The radiation was also applied to grain after harvest, to prevent it from germinating. A total of ten of the containers have been recovered in Georgia, Moldova and Ukraine; no one knows how many more are unaccounted for.
To security experts, the scary thing about cesium 137, commonly produced as a powdery cesium chloride compound, is that a terrorist could fill his pockets with it and sprinkle it in a subway car, an office building or a playground and escape notice. “You don’t need a bomb to spread it around,” says González. The terrorist might die from radiation exposure, but that prospect is not necessarily a deterrent. Scores of people could be contaminated, with many becoming seriously ill or dying.
A little-reported accident in Brazil serves as a warning. In September 1987, a young scrap metal scavenger in Goiânia, the capital of Goiás State in the central Brazilian plateau, took a radiation therapy machine from a deserted clinic and sold it to a junk dealer, who wanted the stainless steel. Then the junk dealer noticed a blue glow from a capsule. Someone dug out the powdery material—it was roughly three ounces of cesium 137—with a screwdriver. Others daubed it on their skin as though it were carnival glitter. A 6-year-old girl played with the material, which coated her hands with cesium dust, as she ate.