A panel of experts warned Congress Wednesday about the potential for a terrorist attack in the United States involving radioactive material. Concern about such a scenario has been on the rise since the September 11 hijacking attacks on the World Trade Center and Pentagon.
Experts told the Senate Foreign Relations Committee that so-called 'dirty bombs' radioactive material dispersed through conventional explosives pose a real threat to the United States.
They said such an attack would not likely result in deaths. Instead, they said, the impact would be psychological and economic.
Steven Koonin, provost at the California Institute of Technology offered a scenario in which terrorists detonated a dirty bomb in a U.S. city. He said dozens of city blocks would be contaminated with radioactivity.
"The area would be evacuated immediately and sealed off, and we can expect hundreds of thousands of people would be showing up at hospitals demanding to be screened for contamination," he said. "There would be at this level of exposure no fatalities from the radiation at all. However, the decontamination would take months, it is possible that buildings could not be economically decontaminated, so dozens of them would have to be razed, and in any event there would be billions of dollars in economic damage."
Mr. Koonin said it would not be difficult to obtain materials to make a dirty bomb, including cesium, cobalt and irridium because they are available in medicine, agriculture, industry and research.
Mr. Koonin and other experts also expressed concern about the potential for terrorists to acquire or build nuclear weapons. Although they said the process is more difficult and thus less likely than acquiring or making a radiological weapons, the potential for death and devastation is far greater.
Harry Vantine of the Lawrence Livermore National Laboratory described what would have happened had nuclear devices been used in the September 11 terrorist attacks on the World Trade Center.
"The loss of life would have been at least two orders of magnitude, one-hundred times larger, maybe more, so that it would have been much more catastrophic," he said.
Mr. Vantine said dealing with the aftermath of such an attack would be, as he put it, 'horrific' because radiation levels around ground zero would be too high.
The experts called for tighter controls of radiological and nuclear materials to prevent them from getting into the hands of terrorists. Committee Chairman Joseph Biden, a Democrat from Delaware, expressed concern about lax controls on nuclear material in Russia.
"The single most urgent threat we face is the access that potential terrorists have to fissile material and knowledge and access to scientific capability that resides in what I describe as the candy store of all candy stores for terrorists, and that is Russia," he said.
Mr. Biden acknowledged that Moscow is working with the Washington to improve controls on nuclear material in Russia, but said more needs to be done.
The head of the U.S. Nuclear Regulatory Commission, Richard Meserve, called for improved technology to detect and intercept nuclear and radiological material that could be smuggled into the United States in luggage or shipping containers.