While diplomats are focused on the newly nuclear North Korea, some say a more likely threat comes from loose nuclear materials in the hands of terrorists. Non-proliferation experts point to a possible source: highly enriched uranium stored at Cold War-era research labs around the world — often under questionable security. Former United States Sen. Sam Nunn tells CBS News that radioactive material at insecure facilities is a "terrorist's dream."
The U.S. Government Accountability Office reports there are at least 128 facilities around the world with at least 20 kilograms (about 44 pounds) of highly enriched uranium.
"That's enough to make a bomb," says Matthew Bunn of Harvard University's Belfer Center for Science and International Affairs. Asked about security at these facilities, he notes that "Most research reactors have only a night watchman and a chain-link fence."
Others criticize the lack of a regulatory authority for the reactors. "There is no international, binding security standard," says Corey Hinderstein at the Nuclear Threat Initiative. That leaves labs in places like Libya, North Korea, Uzbekistan and Nigeria accountable only to their country's own security regulations.
The facilities are not hard to find — the International Atomic Energy Agency (IAEA) lists the research reactors on its Web site.
But local security regulations may not be enough. For example, the Rand Corporation reports that a reactor rod from a facility in Kinshasa, Congo, has been missing since the 1970s. One Congolese rod turned up in the hands of the Italian mafia before it was intercepted during an international sting operation. In 2000, highly enriched uranium was seized in the former Russian state of Georgia on its way to Turkey. In 2001, more was found on three traffickers in France. In addition, the IAEA has identified more than 827 incidents of illicit trafficking of nuclear and other radioactive materials in the past 11 years.
Nunn says while the IAEA and the U.S. Department of Energy have made progress in securing or shutting down the reactors, he's worried they're not moving fast enough, "That's the raw material of terrorism," he says. "And it's not properly secured in many cases."
The Department of Energy says it has accelerated efforts to close down reactors around the world as well as negotiate agreements to replace the use of dangerous fuels with safer materials. The department says six reactors will be converted by the end of this year.
"It's an uphill battle; the conversion process takes a while," says Bryan Wilkes at the National Nuclear Security Administration. He adds that countries with research reactors are proud of their facilities and are often reluctant to give up their highly enriched uranium, "It's a prestige thing."
But despite recent efforts, Hinderstein at the Nuclear Threat Initiative says, "About a dozen conversions have taken place in the past 12 years — and that is not enough."
A deal to convert reactors in Kazakhstan is in the works but is unlikely to be done until 2010. The Energy Department says China has begun discussions with the United States to convert the fuel it supplies to reactors in Nigeria, Ghana, Syria, Pakistan and Iran. But there is still no agreement on the reactors operating inside China.
Nunn tells CBS News that although the facilities house only small amounts of highly enriched uranium, the material could be potentially devastating, "A crude weapon could destroy a city and indeed shake the confidence of the world," he says.
By Laura Strickler