On our drive across the barren, beautiful prairie of Semipalatinsk, a swath of land large enough to contain all of Kuwait, there was nothing to suggest secrecy or danger or the terrible, indelible extremes of human ingenuity. We parked, stepped outside, and the beeps of Yuriy Strilchuk's dosimeter, measuring the level of radiation, started coming faster.With his wraparound shades, ponytail, and long goatee, Strilchuk looked like he could be leading a pack of soldiers into a post-apocalyptic battle. Instead, he was guiding a band of American journalists, equipped with shower caps on their shoes and heads, through a desolate stretch of land in northeastern Kazakhstan. We followed his orders not to breathe through our mouths without face masks or pick up any of the obsidian-looking rocks. But then, gloveless, he bent over and picked one up himself. "Melted earth," he said.
Beginning one morning in August 1949, Soviet scientists repeatedly made this very patch of steppe as hot as parts of the sun. Four years later, the nearby blast of the first Soviet hydrogen bomb—proof the world had entered the thermonuclear age—was 26 times larger than the bomb that had fallen on Hiroshima. After the United States test site in Nevada, this desolate place—dubbed the Polygon, the Russian word for "firing range"—would become the world's largest nuclear testing grounds. In all, 456 explosions were set off here, 340 of them underground after a ban on surface testing in 1963.Strilchuk first came to work on testing at the Polygon in 1990, when this closedoff, 6,950-square-mile site was still in the outer reaches of the Soviet Union. By then, nuclear testing had waned: That year, the USSR, the US, the UK, France, and China conducted 18 nuclear tests, down from a Cold War height, in 1962, of 178. But testing remained part of a dangerous game of technological mastery, scientific understanding, and military one-upmanship.The effects of previous blasts proved to be farther-reaching than military scientists had estimated: To this day, thousands of people living in the nearby city of Semey still struggle with staggering rates of mortality, cancer, and suicide. A 2002 study found that citizens who were exposed to high doses of radiation had an 80 percent higher rate of DNA mutation than control groups, and their children were twice as likely to have genetic aberrations.
The test Strilchuk was preparing for never happened. The Soviet Union dissolved, and on August 29, 1991, Kazakhstan's new president, Nursultan Nazarbayev, shut the Polygon down. Almost overnight, Semipalatinsk became a global symbol for nuclear disarmament and for the country's newfound independence from the Soviet Union.
But the decision also turned the Polygon into a no-man's-land, as Strilchuk and thousands of members of the military abandoned the site. Not long after they left, the scavengers arrived. They ripped out metal and other material from the old, mostly hidden nuclear infrastructure and, knowingly or not, exposed themselves to high levels of radiation. Local authorities were even issuing small mining permits to spur economic growth. (Mining has been a cornerstone of Kazakhstan's economy since Soviet times; today the country is the world's largest producer of uranium.)Plutonium, the bomb fuel that's made from uranium, has a half-life of more than 24,000 years. In the early 1990s, fears that parts of the Soviet nuclear archipelago would fall into the wrong hands pushed Washington into action. One mission in 1994 covertly ferried more than half a ton of weapons-grade uranium out of a Kazakhstani metallurgical plant three hours east of the Polygon. (Recently, the same factory has been proposed as a global nuclear fuel bank for Iran.)At the test site, analysts from the US Department of Defense were especially concerned about Degelen Mountain, home to the underground complex where the Soviets had conducted most of their nuclear tests. Officials later estimated that Degelen contained enough radioactive material embedded in metal and buried in tunnels for an aspiring nuclear power or a terrorist group to produce dozens of nuclear or radiological weapons. In 1996, the Department of Defense officially began a three-year project to "eliminate" the threat posed by the mountain, at a total cost of $6 million. That year, US and Kazakh officials celebrated the first set of tunnel sealings; no definitive accounting was made of what was left inside.
Strilchuk is now the head of training and information at the National Nuclear Center in the town of Kurchatov, a government research facility responsible for overseeing the site. I asked him if, back in 1991, he had imagined that leaving the Polygon might eventually raise the specter of nuclear terrorism. "This was a decision made by the president of Kazakhstan," he said. "What other choice did we have but to leave?"
Siegfried S. Hecker was newly retired from his post as director of Los Alamos, the US nuclear lab where the bomb was born, when he received a troubling tip from a Kazakh acquaintance, a fellow nuclear scientist, in early 1998. Hecker had been on duty during the waning days of the Cold War and was well acquainted with the aftermath of nuclear testing. He traveled to the Polygon and was startled to see how bad the scavenging situation had become in and around Degelen: New machinery and torn-up earth indicated that it had reached an industrial scale.A nuclear bomb might require about 17 pounds of plutonium, maybe less. Hecker estimated that the total plutonium in the area could be as much as 440 pounds. The material, he wrote in a report to officials in Washington, was "in reasonably concentrated form, easily picked up, completely open to [whoever] wants to come." And it was hard to know how much, if any, was missing.To convince dubious Russian officials the situation was dire, Hecker consulted the director of the Russian equivalent of Los Alamos and showed him photos of scavenging at the site. The next morning, physicists who were veterans of the Polygon joined Hecker and a team of Kazakh scientists to sketch out a cooperative effort to mitigate the dangers.
Everyone agreed to stay quiet. During negotiations, the Russians admitted that near Degelen there were more shallow shafts used for testing that were lined with plutonium. And in some instances, they said, not all of the devices in the tunnels had fully detonated, leaving behind pure plutonium or highly enriched uranium.In 2000, the US paid for Kazakh engineers to begin sealing these sites, with their plutonium buried inside, using a mixture of concrete and steel, a technique that Soviet scientists had developed while attempting to contain the nuclear reactor at Chernobyl, in Ukraine, in 1986. The sealing was intended to make the cost of extracting plutonium more expensive than making new plutonium.But the effort was hobbled by legal impediments and delays in US funding. Soon, intruders were reopening some of the shafts and tunnels to get at scrap metal, in some cases brazenly using bulldozers, explosives, and other equipment that belonged to Degelen Mountain Enterprises, the mining company that had helped to seal them to begin with.
September 11 and evidence that al Qaeda was on the hunt for nuclear material put American officials on alert. But the sealing at Semipalatinsk had stalled, and by the time the work began again in 2004, engineers found that 110 of the 181 sealed tunnels at Degelen Mountain had been reopened. The Russians made another startling admission: Buried inside Degelen were another 220 pounds of recoverable plutonium, along with highly sensitive components used for building nuclear weapons.
"Eventually everything gets out in the open." —Siegfried S. Hecker
Department of Defense budget requests for the program spiked from around $5 million a year into the tens of millions. In 2009, according to a secret American embassy cable, a top-ranking US official visited Astana, Kazakhstan's capital, to communicate in person Washington's urgent push to "prevent nuclear-residue material from falling into terrorists' hands." The cable noted that "the risk of proliferation is high" and sealing the rest of the mountain would be "an up-hill battle."A few weeks later, Vice President Joe Biden made a phone call to a high-ranking Kazakh official, imploring him to put an end to the scavenging. At last, a 37-mile area around the mountain was officially declared an "exclusion zone," with surveillance cameras and motion sensors. The US donated at least one small drone to help patrol the area and, all told, spent an estimated $100 million on security measures.The following year, during a meeting at the 2010 Nuclear Security Summit, Presidents Barack Obama, Nazarbayev, and Dmitry Medvedev, of Russia, pledged to finish securing Degelen Mountain. In October 2012, a group of officials and scientists from the US, Kazakhstan, and Russia quietly celebrated the end of their efforts. After 16 years and more than $150 million in US assistance, the project was commemorated with a modest, three-sided monument near the mountain. In three languages, it said simply: 1996–2012. The world has become safer.
Notably absent from the ceremony was the world's central governing body for nuclear activity. Fearing that leaks and bureaucratic entanglements would slow down its work, the coalition had decided to conceal some of the plutonium contamination at the site from the record keepers of the International Atomic Energy Agency. During a 2010 visit by the IAEA, US officials managed to keep inspectors away from more sensitive locations. And recognizing the risks of reporting, IAEA officials appeared eager to play along."We thought about safeguards and asked ourselves, 'Is it worth the agency's efforts to allocate scarce safeguards resources for this material?'" an unnamed IAEA official told the authors of a 2013 report by Harvard's Belfer Center. "We decided it was not worth the cost involved of taking an inventory." As a result, international inspectors were never able to determine if sealing techniques at the Polygon met safety standards for long-term storage of nuclear waste. "Further assistance regarding Semipalatinsk is planned," an IAEA spokesman told me.Nuclear secrets are justifiably guarded. In 2011, at the height of WikiLeaks, then secretary of state Hillary Clinton worried about an "internet age when dangerous information can be sent around the world with the click of a keystroke." She cited nuclear theft as a prime example. "By keeping the details confidential," she said, "we make it less likely that terrorists or criminals will find the nuclear material and steal it for their own purposes."
While Hecker defends the secrecy of the efforts to secure the Polygon, he underscores the importance of transparency around securing nuclear materials. "Eventually everything gets out in the open," he said. "In many areas, such as nuclear security, excessive secrecy backfires because the important information is kept away from workers or officials who have a real need to know."The legacy of secrecy still reigns over the Polygon. While scavengers came within yards of unguarded plutonium, there is no evidence that they gathered any, officials said. But Sergey Lukashenko, director of the Institute of Radiation Safety and Ecology, said that worries remain about newly discovered "hot spots" around the test site where residues of plutonium or highly enriched uranium are present."We really don't know how much material we have," he said. It would be "nearly impossible," but with enough ingenuity and effort, a bad actor could today "in principle" extract enough material from the soil to devise a radiological weapon.
Last year, amid rising tensions over Ukraine, the Russian government informed US officials that it was exiting the nuclear threat-reduction partnership; the US had already dedicated $100 million for the upcoming year to the program, which was set to last until 2018."The Russian government would like to extract itself from Semipalatinsk negotiations," Hecker said. Still, "cooperation between American and Kazakh scientists continues at Semi."Today, there are some fences and barriers around the Polygon, and the most sensitive sites are guarded by surveillance equipment. But there is little to prevent herders and their animals from grazing on the rest of the landscape. Sanctioned mining operations are under way not far from Degelen Mountain, and the National Nuclear Center arranges public tours.Lukashenko and his scientists are also trying to understand the lasting environmental damage at the Polygon, by growing beets and strawberries and chickens and looking for evidence of radiation. This kind of scientific effort—a kind of nuclear archaeology—will probably need to continue here, in some way, forever.Still, he said, some parts of the Polygon were now relatively safe to visit and even to grow crops on. Someday, he hoped, more tourists would come (provided, of course, they didn't take any souvenirs).Follow Alex on Twitter.This story was reported with assistance from the International Reporting Project. Read more about nuclear topics on Motherboard.