Alatau, Kazakhstan—Researchers wearing pristine white overcoats, pressed white slacks, and something akin to a chef’s hat stand atop the light water nuclear reactor at Kazakhstan’s Nuclear Physics Institute.

After making a few adjustments, they point a gun-like radiation monitor to the silent behemoth below, ensuring that nothing has escaped its beating heart. Deep inside is an array of metal arteries—a fuel assembly—where the fissile reaction is taking place thanks in part to a small amount of highly enriched uranium, or HEU.

As the more potent version of uranium fuel, HEU has become the focus of global efforts to secure nuclear materials. Once widely produced, and key to both civilian nuclear projects and weapons programs, large stockpiles remain around the globe. Most caches are properly secured. Other collections, some of it from spent fuel, are seemingly forgotten.

Here at Alatau, you can ask where they keep their remaining HEU, but they won’t tell you. They will tell you it takes “three keys and three people” to get to it.

“All the nuclear materials here are kept under strict and well-organized security measures,” said Peter Chakrov, deputy director of the Nuclear Physics Institute, who recently showed two Stanley Foundation staffers around the facility. “We are safeguarded by the International Atomic Energy Agency. We have inspectors here every month.”

Soon, the scientists here will work to convert this research reactor to use a fuel assembly that runs on low-enriched uranium—a non-weapons-grade material that does not pose the same black-market or terrorist risks as HEU. The HEU kept at the facility will then be down-blended at the Ulba Metallurgical Plant, a huge industrial complex that produces reactor fuel in Ust-Kamenogorsk, a gritty northeastern city.

Strong on Nonproliferation
The sprawling Ulba plant—protected by soldiers carrying Kalashnikovs, redundant security checkpoints, and a large German Shepherd—is no longer a security concern. But the large amounts of HEU it once housed was.

In the days of the Soviet Union, Kazakhstan was awash in HEU as Moscow steamed forward in its nuclear experiments, the most damaging of which involved detonating more than 700 bombs in this country’s vast northern steppe. More than two million people in the area were exposed to radiation. Today the cancer rate is three times the norm and birth defects, infertility, and deformities are common.

Following the Soviet collapse, Kazakhstan’s President Nursultan Nazarbayev—aware of the irreversible damage nuclear testing caused his country and its people—chose to disavow nuclear weapons, giving up the world’s fourth largest nuclear arsenal.

Soon after in 1994, a clandestine joint US-Kazakh mission, code-named Project Sapphire, was implemented to remove the bulk of HEU from the Ulba plant. Overnight, more than half a ton of HEU was airlifted out of Kazakhstan to Tennessee to be down-blended into safe reactor fuel.

“That was a very magnanimous, very important gesture in the realm of arms control,” said Steve Black, chief operating officer of the National Nuclear Security Administration, a division of the US Department of Energy. “The Kazakhs have always been extremely good partners with us and the rest of the world in our nonproliferation and arms control efforts.”

Kazakhstan has also shut down a plutonium breeder reactor, and the fuel generated from the reactor is being moved to a more secure location within the country. “In my view it should leave Kazakhstan entirely because it needs to be reprocessed into forms that can no longer be used in weapons, and that can most easily be done in Russia,” said Matt Bunn, an associate professor at Harvard’s John F. Kennedy School of Government and nuclear nonproliferation expert.

Securing the Border
Kazakhstan is cooperating with international nuclear security efforts in another important way: border crossings.

Four times the size of Texas, Kazakhstan shares long borders with Russia, China, Kyrgyzstan, Uzbekistan, and Turkmenistan. Since 2006, Kazakhstan has installed sophisticated radiation detection equipment at 16 border crossings, including four recent installations funded by the United States and Norway. By 2015 the systems will be present at a total of 30 crossings.

Much of the US funding comes from the National Nuclear Security Administration’s Second Line of Defense program, which has deployed radiation monitoring devices at 335 border points, airports, and seaports around the world.

At a checkpoint on the Russian border near the small village of Aul, a semi-tractor trailer drives between two large white panels that monitor whether the cargo contains any radiation. If it does, alarms sound and will prompt a secondary, more thorough inspection, said Zhenis Zhanpeisov, the commander of customs control at the checkpoint. “The monitoring is taken very seriously and is emphasized as a priority by our leadership,” Zhanpeisov said.

While Kazakhstan is often praised for its efforts to secure nuclear materials and prevent trafficking, the hundreds of miles of unfenced steppe between the checkpoints raise obvious questions about the monitoring system’s efficacy.

Zhanpeisov couldn’t say how they might prevent potential black-market traffickers from avoiding the checkpoints altogether and moving radioactive material across the border.

“All I can say is that it’s very secure,” he said.