KURCHATOV, Kazakhstan — Twenty years after the Soviet Union collapsed and tens of thousands of soldiers abandoned their posts at this remote site in northeastern Kazakhstan, the footprints of another great power — the United States — are increasingly visible.
The United States Defense Department has paid for aerial drones to spot intruders, and for motion detectors that signal when a person, or a horse or a car, crosses into restricted territory. The classified project aims to keep terrorists away from what the Soviets left behind in patches of earth and a warren of tunnels that they used for atomic testing: among other things, plutonium and highly enriched uranium that Western scientists fear could be used to build an improvised nuclear device.
Protecting this material has meant teasing out nuclear secrets that have been kept for decades. Russia is warily sharing archival material about Soviet-era tests, and the United States is paying to remove or secure weapons-grade material. Kazakhstan is providing the labor, but because it is not a nuclear power, its officials are forbidden from learning exactly what it is that they are guarding.
“People ask me, are we doing the right thing, closing access to the tunnels?” said Kairat K. Kadyrzhanov, general director of Kazakhstan’s National Nuclear Center, which manages the test site. “And I say I do not know what is there, and I do not have the right to know.”Continue reading the main story
The edge of the Semipalatinsk Test Site is a two-hour drive from the nearest large city, across an expanse of dun-colored, featureless steppe.
In 1948, racing to break the American monopoly on nuclear weapons, the Soviet Union selected this stretch of land to test their own. Local villagers knew only that the earth quaked, making china shudder on the shelf; years later, charts showed radioactive plumes that settled over population centers.
With the collapse of the Soviet Union, 20,000 to 30,000 troops withdrew from their positions, leaving 500 Kazakh soldiers to guard the site, Mr. Kadyrzhanov said.
Ever since then, the test site — or, specifically, the fissile material and fission products left there — has been a concern for the United States. The project has continued behind a curtain of secrecy, with a few exceptions; in 2003 Kazakh officials told a reporter for Science magazine about “Operation Groundhog,” in which plutonium-contaminated earth was paved with a two-meter-thick slab of steel-reinforced concrete to protect it from terrorists who might cart it away to use in a dirty bomb.
Officials from the Defense Department and the State Department would not comment. But cables published by WikiLeaks last year describe an urgent push to “prevent nuclear residue material from falling into terrorists’ hands,” as a top defense official put it in 2009. One describes it as “the most critical” of all the American-financed projects to secure nuclear materials in the former Soviet Union.
After above-ground testing was banned, the Soviets detonated 295 devices in 181 tunnels under the Degelen Mountains, according to a study published last year by Kazakhstan’s Institute for Radiation Security and Ecology. Each explosion consumed between 1 and 30 percent of the device’s fissile material, leaving the remaining fuel mixed with debris and melted rock underground, according to the study.
President Obama’s inauguration marked a “radical change of attitude” toward security at the site, and American officials demanded a fivefold acceleration in the work, Mr. Kadyrzhanov said. Meanwhile, Russia, which for years refused to share Soviet documents about the site, has been more forthcoming, he said.
“The danger that Russia is keeping something from us has been diminished,” he said.
With the Soviet collapse, poverty and disorder lapped at the edges of the Semipalatinsk Test Site, still littered with radioactive hazards.
Activity ended so abruptly that a nuclear device lowered into one tunnel in preparation for a test sat unexploded until 1995, when technicians managed to destroy it without creating a nuclear reaction, according to the National Nuclear Center.
Meanwhile, the vast test site was unsecured and scavengers were combing the tunnels for copper wire that could be sold to Chinese dealers. About 10 people are known to have died from crawling into a tunnel and breathing contaminated air, said Yuri G. Strilchuk, director of training and information at the National Nuclear Center.
Early on, the problem seemed manageable. In 1999, Senator Richard Lugar, Republican of Indiana, announced that an American-financed effort was sealing up the last of the tunnels. But local scavengers used bulldozers and explosives to re-open them, in some cases dislodging the 50-meter plugs of reinforced concrete, Mr. Kadyrzhanov said. By 2004, 110 of the 181 sealed tunnels had been reopened, according to the National Nuclear Center.
“The mentality of a Soviet person has changed,” Mr. Kadyrzhanov said. “Fifty years ago, if they saw barbed wire or a concrete wall they would go away. But now, it’s the opposite — they will climb the fence just to see what is inside.”
The effort that began afterward was more urgent, more costly and more secretive, perhaps in part because after Sept. 11, 2001, there was anxiety that radioactive materials would be used to construct dirty bombs. Vladimir V. Putin, then Russia’s president, met with President Nursultan A. Nazarbayev of Kazakhstan in 2004 to discuss the transfer of more archived documents from Russia.
By 2009, American officials were increasing the pressure on their Kazakh partners to finish sealing the tunnels within two years, noting uncertainty about how long the three countries would successfully cooperate, one cable says.
Among the sensitive issues is that by analyzing debris left behind by the explosions, scientists might be able to determine the ingredients of the devices themselves. Late-stage Soviet tests there involved superefficient blasts, in which an unusually large percentage of fissile material was consumed, and Russians may fear that American scientists will excavate the tunnels, Mr. Kadyrzhanov said. Terrorists may also be seeking to access this technology, he said.
“The main secret of a bomb is the recipe of the charge,” he said. “I could take a sample and make a conclusion about the recipe.”
Mr. Kadyrzhanov said the cavities themselves were being filled with concrete that absorbed residue plutonium, so that “it is easier to make plutonium from scratch at a nuclear station” than to extract it.
“For example, a bad guy becomes president of Kazakhstan after Nazarbayev, and says, ‘I want to extract plutonium from this charge,’ ” he said. “He will have to work very, very hard. We are closing it down so that it will be practically impossible for future generations to get it out.”Continue reading the main story