By William J. Kole, Associated Press, 04/10/03

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VIENNA, Austria -- American troops who suggested they uncovered evidence of an active nuclear weapons program in Iraq unwittingly may have stumbled across known stocks of low-grade uranium, officials said Thursday. They said the U.S. troops may have broken U.N. seals meant to keep control of the radioactive material.

Leaders of a U.S. Marine Corps combat engineering unit claimed earlier this week to have found an underground network of laboratories, warehouses and bombproof offices beneath the closely monitored Tuwaitha nuclear research center just south of Baghdad.

The Marines said they discovered 14 buildings at the site which emitted unusually high levels of radiation, and that a search of one building revealed "many, many drums" containing highly radioactive material. If documented, such a discovery could bolster Bush administration claims that Saddam Hussein was trying to develop nuclear weaponry.

Lt. Cmdr. Charles Owens, a spokesman for the U.S. Central Command, said officials there have not heard anything through military channels about a Marine inspection at Tuwaitha.

The Vienna-based International Atomic Energy Agency, which has inspected the Tuwaitha nuclear complex at least two dozen times and maintains a thick dossier on the site, had no immediate comment.

But an expert familiar with U.N. nuclear inspections told The Associated Press that it was implausible to believe that U.S. forces had uncovered anything new at the site. Instead, the official said, the Marines apparently broke U.N. seals designed to ensure the materials aren't diverted for weapons use -- or end up in the wrong hands.

"What happened apparently was that they broke IAEA seals, which is very unfortunate because those seals are integral to ensuring that nuclear material doesn't get diverted," the expert said, speaking on condition of anonymity.

The Army Times, meanwhile, reported that troops with the 101st Airborne Division have unearthed 11 shipping containers, filled with sophisticated lab equipment, buried at a chemical plant in Karbala. It said the equipment's value and evidence that some of it may have been smuggled into Iraq raised suspicions that the facility had been used to manufacture chemical weapons.

U.N. arms inspectors visited a facility in the immediate vicinity of the chemical plant Feb. 23, but did not find the buried equipment. Officials at the U.S. Central Command suggested that no conclusions should be drawn.

Several tons of low-grade uranium has been stored at Tuwaitha, Iraq's principle nuclear research center and a site that has been under IAEA safeguards for years, the official said. The Iraqis were allowed to keep the material because it was unfit for weapons use without costly and time-consuming enrichment.

Tuwaitha contains 1.8 tons of low-grade enriched uranium and several tons of natural and depleted uranium.

The uranium was inspected by the U.N. nuclear agency twice a year and was kept under IAEA seal -- at least until early this week, when the Marines seized control of the site.

The U.N. nuclear agency's inspectors have visited Tuwaitha about two dozen times, including a dozen checks carried out since December, most recently on Feb. 6. It was among the first sites that IAEA inspectors sought out after the resumption of inspections on Nov. 27 after a nearly four-year break.

On at least one occasion, inspectors with special mountaineering training went underground there to have a look around, according to IAEA documents.

David Kay, a former IAEA chief nuclear inspector, said Thursday that the teams he oversaw after the 1991 Gulf War never found an underground site at Tuwaitha despite persistent rumors.

"But underground facilities by definition are very hard to detect," he said. "When you inspect a place so often, you get overconfident about what you know. It would have been very easy for the inspectors to explain away any excessive radiation at Tuwaitha. The Iraqis could have hidden something clandestine in plain sight."

American intelligence analysts said before the U.S.-led campaign began that new structures photographed at Tuwaitha might indicate a revival of weapons work. IAEA inspectors checked but found nothing.

The Tuwaitha complex, run by the Iraqi Atomic Energy Commission on a bend in the Tigris River about 18 miles south of Baghdad, was the heart of Saddam's former nuclear program and was involved in the final design of a nuclear bomb before Iraq's nuclear program was destroyed by U.N. teams after the 1991 Gulf War.

The IAEA, charged with the hunt for evidence of a nuclear program in Iraq, told the Security Council just before the war that it had uncovered no firm evidence that Saddam was renewing efforts to add nuclear weapons to his arsenal.

IAEA Director-General Mohamed ElBaradei, clearly wary of any coalition claims, said this week that any alleged discoveries of weapons of mass destruction in Iraq would have to be verified by U.N. inspectors "to generate the required credibility."

ElBaradei said the inspectors should return as soon as possible, subject to Security Council guidance, to resume their search for banned arms.