Nation

'Dirty bomb' plan alleged by feds would yield a dud

NEW YORK - The "dirty bomb" allegedly planned by terror suspect Jose Padilla would have been a dud, not the radiological threat portrayed last week by federal authorities, scientists say. At a June 1 news conference, the Justice Department said the alleged al-Qaida associate hoped to attack Americans by detonating "uranium wrapped with explosives" in order to spread radioactivity. But uranium's extremely low radioactivity is harmless compared with high-radiation materials - such as cesium and cobalt isotopes used in medicine and industry that experts see as potential dirty-bomb fuels. "I used a 20-pound brick of uranium as a doorstop in my office," American nuclear physicist Peter D. Zimmerman, of King's College in London, said to illustrate the point. Zimmerman, co-author of an expert analysis of dirty bombs for the U.S. National Defense University, said last week's government announcement was "extremely disturbing - because you cannot make a radiological dispersal device with uranium. There is just no significant radiation hazard." Other specialists agreed. "It's the equivalent of blowing up lead," said physicist Ivan Oelrich of the Federation of American Scientists. When Padilla was arrested in June 2002, after returning to Chicago from Afghanistan and Pakistan, Attorney General John Ashcroft said the ex-Chicago gang member and Muslim convert had planned a dirty bomb that could "cause mass death and injury." Washington, D.C., was the likely target, his department said. But it wasn't until Deputy Attorney General James Comey's briefing for reporters last week that authorities said Padilla had uranium in mind for his radiological dispersal device, or RDD, the technical term for such a weapon. Padilla's lawyer, Donna Newman, said Wednesday of the dirty-bomb allegation that U.S. authorities "should have known that this was nonsense." "When they frightened everybody, what were they trying to do, if they knew better? To show the administration is on top of things?" she asked.