Plutonium Mountain: Inside the 17-Year Mission to Secure a Legacy of Soviet Nuclear Testing

 The 18,000 km² expanse of the Semipalatinsk Test Site (indicated in red), attached to Kurchatov (along the Irtysh river), and near Semey, as well as Karagandy, and Astana. The site comprised an area the size of Wales

Report, Project on Managing the Atom, Belfer Center for Science and International Affairs, Harvard Kennedy School; August 15, 2013. Authors: Eben Harrell, Associate, Project on Managing the Atom, David E. Hoffman; Belfer Center Programs or Projects

 INTRODUCTION

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 and in surrounding bore holes by filling portions of the tunnels and holes with a special concrete, greatly reducing one of the largest nuclear security threats since the collapse of the Soviet Union. They unveiled a three-sided stone monument, etched in English, Russian, and Kazakh, which declared: “1996-2012. The world has become safer.”

The story of the operation at Semipalatinsk is a tale of scientists working together to achieve real results in reducing nuclear threats. It began in 1995, after the collapse of the Soviet Union, when experts from the Los Alamos National Laboratory were told during a visit to Kazakhstan that plutonium residue in recoverable form was likely to have been abandoned at the test site. Two years later, in 1997, Siegfried S. Hecker, just retiring as director of Los Alamos, decided to look more closely. Hecker, who helped pioneer cooperation with his counterparts in the Soviet and later Russian nuclear weapons laboratories, used personal connections to push for action. He succeeded in enlisting the cooperation of Russian nuclear scientists who had been involved in the testing program in Kazakhstan before the Soviet collapse.