After the cold war ended in 1991, the specter of rogue states using portable nuclear devices, or "suitcase nukes,'' helped spur cooperative efforts to seal up Russia's old nuclear factories, destroy existing weapons, and find peacetime work for jobless bombmakers.
But now a new kind of threat looms.
Earlier this year, the arrest of an alleged Al Qaeda operative in the US on suspicion of plotting to build a radiological dispersal device, or "dirty bomb,'' highlighted growing concerns that these improvised bombs, not nukes, present more immediate danger. Because they spread quickly over a wide area and are relatively easy to make just a few grams of highly enriched uranium or plutonium mixed with conventional explosives they are more likely to be used by terrorists.
Last week, some 240 delegates from 26 countries gathered in London for a three-day conference to boost international cooperation in securing nuclear and radiological materials and fighting nuclear terrorism.
Cohosted by the US Department of Energy and Moscow's Kurchatov nuclear institute, the meeting drew lawmakers, scientists, atomic-weapons experts, and security officials from nations as diverse as Kazakhstan and Japan. Closed-door sessions revolved around topics of radiological threat reduction, trends in illicit trafficking, materiel protection, control and accounting, and the challenge of preventing nuclear and radiological terrorism.
This challenge was made clear in a Balkan delegate's comments after the conference. Aleksandar Cvetkov, head of interior affairs for the Republic of Macedonia, said that his country does not produce nuclear materials but that such dangerous materials are smuggled through the country, using illegal drug and arms trafficking routes.
He said that while information on arrests involving nuclear materials at Macedonia's borders is confidential, the occurrence of such smuggling had risen noticeably since the attack on the World Trade Center.
"Our control of certain border points is not so strong,'' Mr. Cvetkov said through an interpreter. "We want directions on how to work; how to locate the fragile points. And then we hope to get some help with equipment and training. Our aim is to be part of a more global system so that we can help prevent another September 11.''
Unlike nuclear stockpiles, which are based in only a handful of countries, radiation sources are ubiquitous, and it is nearly impossible to keep track of them all. About 375 sources of radioactive material, which can be used to treat cancer, preserve food or check for welding errors in pipelines, are reported lost or stolen in the US each year. In other countries, the exact amount of unaccounted for, or "orphaned,'' radioactive material is unknown. Officials say they often do not know material has been lost until it is found.
The US Department of Energy has joined with Russia's Ministry of Atomic Energy, or MinAtom, and the International Atomic Energy Agency (IAEA) to try to secure some of Russia's orphaned radioactive sources.
Russia and the newly independent states of the former USSR are believed to have about 600 metric tons of weapons-usable material "enough to produce more than 41,000 nuclear devices,'' according to a 2001 report by the department's Material Protection, Control, and Accounting Program. About a third of that material has not been officially secured, officials said.
Last month, the G-8 Global Partnership Against the Spread of Weapons and Materials of Mass Destruction pledged up to $20 billion toward new and expanded projects on nuclear security.
Nonproliferation efforts include finding ways to put bomb ingredients to commercial use. Sen. Richard Lugar, (R) of Indiana, announced last Thursday that more than 6,000 nuclear warheads worth of Russian bomb material has been eliminated by converting it into fuel to make electricity.
Among other developments:
The US and Russia have agreed to dispose of 68 metric tons of surplus plutonium enough material for over 10,000 nuclear weapons.
Security upgrades will expand from four to 21 border sites in Russia and Ukraine an important contribution to efforts to curtail nuclear smuggling.
In addition to a database that helps track and account for the nuclear and radiological material, the US has provided portal monitors to countries in the former USSR and Europe and X-ray vans at airports to detect radioactive sources and possible shielded sources in luggage. But Kenji Murakami, director of the Department of Safeguards at the IAEA in Vienna, noted that only 70 nations are members of the voluntary database. The system "needs to be more timely and more accurate,'' he said. "Much has been done. But it isn't enough.''
Conference recommendations also included enacting tougher laws to deal with weapons smuggling and setting up telephone and Internet-based "hotlines'' to help countries improve regulation and disposal of nuclear and radiological materials.