What Lies Beneath

There's one fear that keeps leaders from across the globe awake at night: The prospect that somehow, somewhere, criminals or terrorists are getting their hands on the essential ingredients of a nuclear weapon. At the nuclear summit in South Korea last month, policymakers gathered to prevent that nightmare from becoming a reality by launching an initiative to secure all vulnerable nuclear stockpiles within four years. But despite the fanfare surrounding the summit, one of the greatest recent successes in this initiative has thus far remained buried -- both literally and figuratively.

In an extraordinary feat of engineering and international cooperation, U.S., Russian, and Kazakh scientists, engineers, and miners recently secured enough fissile material for a dozen nuclear weapons that had been left behind vulnerable to theft in tunnels formerly used by the Soviet Union for underground nuclear weapons tests in Kazakhstan.

The formerly secret mission was launched in 2005 at the encouragement of an intrepid U.S. weapons expert, after it was discovered that metal scavengers had penetrated the abandoned tunnels. The project received attention from the highest levels of government -- both President George W. Bush and President Barack Obama monitored its progress. It is an example of the quiet but essential international cooperation that is urgently needed to prevent terrorists from ever obtaining a nuclear weapon.

How this extraordinary, seven-year effort came to pass deserves the long version of the story. From 1961 to 1989, the Soviet Union conducted hundreds of nuclear tests and experiments at a remote and forbidding site called Degelen Mountain. Located within Kazakhstan's Semipalatinsk test range, the site is about the size of New Jersey and located some 300 miles east of Astana, the second coldest capital city in the world. It was chosen by the Soviets precisely because it is so desolate: Temperatures soar to over 100 degrees Fahrenheit in the summer and plunge to -40 degrees in the winter. Blizzard conditions are common -- remarkably, they sometimes make the test site more accessible by filling in potholed roads, which have gone unrepaired since the Soviet era, with ice and snow.

The Soviets conducted over 450 nuclear detonations at Semipalatinsk, mostly in tunnels hundreds of yards long, buried deep below ground. Roughly 40 of the tests were small explosions with very low nuclear yields, so the fissile material -- highly enriched uranium or plutonium -- was neither consumed by the blasts nor infused into the molten rock created by them. Instead, according to one senior Obama administration official, hundreds of pounds of weapons-grade fissile material was "readily recoverable" in the tunnels. This did not matter much so long as the KGB, the USSR's premier internal security agency, held an iron grip on the Soviet Union, with special attention paid to remote and sensitive nuclear sites like Semipalatinsk. But when the Soviet Union crumbled into 15 independent countries in 1991, all that changed.

With the dissolution of the Soviet Union, Kazakhstan gained its independence. But it came with a catch: Kazakh officials were now responsible for an environmental catastrophe, as well as a proliferation risk, at the former Soviet test site.

Indeed, the world did move quickly -- but sadly, insufficiently -- to contain this risk. Working under Cooperative Threat Reduction programs, which were launched by President George H.W. Bush's administration, to dismantle the former Soviet nuclear establishment in the 1990s, U.S. engineers helped to barricade 181 tunnels and demolish their entrances to prevent them from ever again being used for nuclear testing -- but, in a pre-9/11 world -- they paid little attention to the possibility of fissile material left in the testing tunnels.

The extreme weather conditions and the passage of time eventually cracked and eroded the material sealing the testing tunnels. By 2004, scavengers looking for scrap metal to sell had broken into some of them. Reports of the looting alarmed U.S. officials, who feared that fissile material could be at risk. The U.S. government encouraged and aided the Kazakh government to improve security at the site until more permanent measures could be implemented. Astana declared an exclusion zone, where a ban on trespassing was strictly enforced, and mounted patrols to guard the tunnels and the surrounding area.

Next, nuclear weapons scientists who once sat on opposite sides of the Iron Curtain determined how best to secure the material. They decided to fill the test chambers with a specialized grout, which bonds chemically with fissile material to render it useless for weaponization. In some tunnels, it would be necessary to mine horizontally to reach the test chamber where the nuclear experiments took place.

It was hazardous work: The old tunnels were partially collapsed and dangerous to enter. At other sites, the cement could be pumped from above after drilling into the test chambers. In every case, once the work was done, removing the cement would require a major mining operation that required specialized equipment and was beyond the capability of scavengers or would-be terrorists. Because fissile material was involved, the International Atomic Energy Agency (IAEA) was also informed of the project.

The United States, working with Kazakhstan and Russia, spent $150 million on the project -- a tiny amount of money given the threat posed by the material required for one nuclear weapon falling into the hands of criminals or terrorists, let alone enough material for a dozen weapons.

But the hard work to secure the site couldn't have been accomplished without America's local Kazakh partners. Four 10-man Kazakh crews worked year round for seven years to dig out, drill into, and ultimately fill the former nuclear test chambers with the special cement. They lived in modified 40-foot cargo containers and braved extreme conditions. One frigid day on the steppe, a work crew had to take a blow torch to the side of their frozen water tank truck just to melt a supply of drinking water. The Kazakh work crews were guided by Russian nuclear scientists and U.S. experts from the Pentagon's Defense Threat Reduction Agency and the Los Alamos National Laboratory, who traveled to the site every four to six weeks, also braving difficult conditions.

U.S. assistance also went to help the Kazakh government enforce its exclusion zone, pay for fences, patrol vehicles, aerial surveillance drones, and even seismic sensors disguised as rocks to alert security forces to the presence of an intruder. These measures have worked. No scavenger activity has been observed at the site since 2009.

Related initiatives to secure other types of nuclear material are ongoing around the world -- and more will be required. The work at Degelen Mountain is a model of how the international community, and Republican and Democratic administrations alike, is cooperating to reduce the nuclear threat. The world is safer for this effort, and it deserves to be recognized.