Plutonium Mountain: The 17-year mission to guard remains of Soviet nuclear tests

Summary

On the desolate steppe of eastern Kazakhstan, the Soviet Union carried out 456 nuclear explosive tests during the Cold War at the Semipalatinsk Test Site, which sprawls over an area approximately the size of Belgium. Of these, the Soviet Union performed 116 tests in the atmosphere, and 340 underground. While some of the nuclear tests at Semipalatinsk involved atomic explosions, other experiments were designed to study the impact of conventional explosives on plutonium and highly enriched uranium (HEU), the fissile materials used in nuclear bombs, or to ensure the safety of nuclear weapons during a simulated accident such as a fire or nearby explosion. Some of these tests—particularly tests involving plutonium—did not vaporize the material in a nuclear blast. It remained in tunnels and containers, in forms that could be recovered and recycled into a bomb. In addition, the Soviet Union discarded equipment that included high-purity plutonium that would have provided materials and information that could lead to a relatively sophisticated nuclear device if it had been found. When scientists and military personnel withdrew from Kazakhstan following the collapse of the Soviet Union, they abandoned tunnels and bore holes filled with plutonium residue—enough plutonium, if fully reclaimed, for terrorists or a state to construct dozens of nuclear bombs. Between 1991 and 2012, scavengers looking for valuable metal and equipment from the former Soviet test site came within yards of the unguarded fissile material; in two cases the scavengers broke into the vessels used to contain some of the experiments, although there is no evidence that they removed any plutonium. In October, 2012, at the foot of a rocky hillside, at a spot known as Degelen Mountain, several dozen Kazakh, Russian, and American nuclear scientists and engineers gathered for a small ceremony that marked the completion of a 17-year, $150 million operation to secure the plutonium in the tunnels of Degelen Mountain a...