Dirty bomb: Deadly ingredients are easy to obtain

The main source for dirty bombs is the former Soviet Union, but the United States is far from leak-proof, according to nuclear weapons experts.

The main source for dirty bombs is the former Soviet Union, but the United States is far from leak-proof, according to nuclear weapons experts.

A recent report by specialists at Harvard University said that only 40 per cent of Russia's bomb-grade materials and less than one-seventh of its enriched uranium stocks had been properly secured. A batch of nearly five pounds of the latter, which vanished years ago, is still unaccounted for.

Last year discarded devices containing Strontium-90, a radioactive waste product, were discovered in the former Soviet Republic of Georgia. Fearing that other such items might be used in dirty bombs, the International Atomic Energy Agency ­ the main international nuclear watchdog, which is based in Vienna ­ sent teams to the region to search for more.

But America, the overwhelmingly dominant nuclear power, is also a possible source. Its Nuclear Regulatory Commission admits that at least 835 devices containing radioactive material have vanished in the past five years.

The most reliable assessment of the worldwide problem comes from the Institute for International Studies at Stanford University, whose database records some 850 incidents from the past decade.

If anything, databases understate the difficulties. Lyudmila Zaitseva, a researcher from Kazakhstan, said only a fraction of incidents in the former Soviet Union are detected and recorded. "We calculate that radioactive material being detected as missing or stolen is probably 10 to 30 per cent of what's really gone," she said.

Estimates put the world stock at hundreds of tons of plutonium and enriched uranium. A small nuclear bomb could be made from less than 50lbs of uranium, or from a sample of plutonium small enough to fit inside a Coke can.

In the former Soviet republics, alienated and underpaid nuclear scientists abound, as well as plant workers and guards protecting materials worth millions who earn $200 a month. Russia's nuclear security system is more vulnerable now. In 1998, when a local police official in the Chelyabinski region took credit for cracking a plot to steal more than 40lbs of weapons-grade uranium.