Experts: 'Dirty' nukes are real threat

WASHINGTON, March 6 (UPI) -- The United States must accept that terrorists could use non-weapons-grade nuclear material to attack cities, several scientists told a Senate committee Wednesday.

The Senate Foreign Relations Committee discussed radiological weapons that would not involve nuclear explosions but the spread of radioactive contamination among a civilian populace.

Sen. Joseph Biden, D-Ill., committee chairman, noted such weapons previously had been thought to be unusable, since the extremely radioactive materials needed would end up killing anyone creating such a device. The suicidal Sept. 11 attacks, however, proved that theory wrong, he said.

"I just want us to look realistically at the threat and to make some realistic decisions, based on priorities and limited resources, after we have heard all the evidence," Biden said. "We need to know what has to be done to ensure that the threat remains exactly that; a threat and nothing more."

The witnesses, including Steven Koonin, a physics professor and provost of the California Institute of Technology in Pasadena, said radiological terrorism is more than just a fear, but a plausible occurrence with major consequences.

"Gram for gram, radioactive material can be at least as disruptive as weaponized anthrax," Koonin testified.

Casualties from an isotope-dusted conventional explosive or other attack likely would be light, Koonin said. Current guidelines on radiation exposure, to say nothing of public misconceptions and fears, could prompt the long-term abandonment of highly populated areas, he said.

Witnesses estimated cleanup costs from a sizeable radiological attack in a major city could easily exceed tens of billions of dollars.

"The danger presented is real and credible; it would not be a trivial undertaking by any means, but it is doable," testified Henry Kelly, president of the Federation of American Scientists.

If the Hart Senate Office Building in Washington had been contaminated with radioactive cesium instead of anthrax, Kelly said, the only way to meet Environmental Protection Agency safety guidelines would have been to abandon or demolish the building.

Kelly's testimony included a disturbing study by the Federation of American Scientists of possible radiological attack scenarios. If terrorists could manage the very difficult task of obtaining a rod of cobalt used in food irradiation, and were able to survive transforming that rod into a powderlike form, a bomb containing that material could contaminate hundreds of square miles.

An explosion at the southern tip of Manhattan in New York could spread the cobalt in an oval stretching into southwest Connecticut, the FAS study said. Strict EPA guidelines would require either decontamination or destruction of structures within the oval. Even if officials used less-stringent rules Russia imposed after the Chernobyl accident, dozens of blocks in lower and midtown Manhattan would be permanently closed in the cobalt scenario.

The United States already has put several layers of defense in place to prevent such a scenario, said Harry Vantine, program leader for counterterrorism and incident response at Lawrence Livermore National Laboratory in Livermore, Calif., which is operated by the University of California for the Department of Energy. Weapons-grade material is under tight control, Vantine testified, but other radiological sources have lesser degrees of security.

The country should review all facilities using such sources to determine where defenses need to be strengthened, Vantine said. Lawmakers and agency heads should avoid the temptation to shortchange other programs to pay for moves such as this, he added.

"Programs in nonproliferation, proliferation detection, counterterrorism and homeland security are closely linked and must not be selected 'either/or' or conducted in isolation from each other," Vantine testified.

Several witnesses said expanding radiation sensor networks to put "one on every lamp post" would be another simple but very effective measure in preventing radiological attacks. Since shielding a weapon's radioactivity would be difficult, the sensors could provide enough advance warning to thwart an attack.

"The monitoring technology is well-established, the power and maintenance requirements are likely to be minimal, and the specificity and robustness will be high," Koonin testified.