December 6, 2001	Thursday	Ramazan 20, 1422

WASHINGTON: Finding enough radioactive material to make a ”dirty bomb” might be relatively easy, experts say, but the effects of such a weapon could never remotely approach those of a nuclear explosion.

“The nuclear device is a weapon of mass destruction,” said nuclear scientist Siegfried Hecker, former director of the Los Alamos National Laboratory. “Dirty bombs are weapons of mass disruption, in terms of frightening people, the cleanup and the potential economic consequences.”

Interest in dirty bombs has deepened recently among US intelligence officials because of mounting evidence that Osama bin Laden and his Al Qaeda network may be developing expertise in building them. Homeland Security Director Tom Ridge said on Tuesday, that US authorities had no information that Osama actually had made such a weapon, and added that the Bush administration’s latest anti-terrorist alert had nothing to do with a dirty bomb threat.

The technology to make the bomb is relatively simple: find some radioactive material-anything from spent fuel rods from nuclear power plants to leftovers from a radiology lab; wrap it around a core of ordinary high explosive; and detonate it so that contamination spreads over the widest possible area.

This is not a nuclear explosion. Those occur when two subcritical masses of highly processed radioactive material are thrust suddenly together, triggering a violent chain reaction and release of energy. Blast effects and heat from a nuclear device can flatten city blocks and kill thousands of people, while the only blast from a dirty bomb is provided by the explosive. Still, while fatalities may be light, a dirty bomb can cause a higher incidence of cancer in local residents decades after the attack, and more immediately, provokes the same me psychology of fear as a chemical or bioweapons threat. In that respect, Hecker said, a dirty bomb “would have an instant terrorist effect.”

The bomb-maker must always contend with a Catch-22, for the more powerful the radiation source, the more dangerous it is to handle; the weaker the source, the less damage the weapon will cause.

“The dirtiest spent fuel is from a nuclear reactor,” said senior staff scientist Lisbeth Gronlund of the Union of Concerned Scientists. “It is very radioactive, and one reason to consider it proliferation-resistant is that the dose you get from stealing it would kill you pretty quickly.”

The International Physicians for the Prevention of Nuclear War argued that a plutonium dirty bomb would have almost no immediate health consequences, and even though it could lead to cancer years after the attack, the effects “would probably not be dramatic.” —Dawn/LAT-WP News Service (c) The Washington Post.