Seibersdorf, Austria ? In a sprawling U.N. laboratory tucked among snow-speckled beet fields, a scientist in surgical scrubs fusses over a battery of sophisticated radiation-detecting equipment.

Within days, the sterile room will serve as an unlikely venue for a dramatic showdown between science and Saddam Hussein.

Experts with the International Atomic Energy Agency, leading the hunt for nuclear weaponry in Iraq, are gearing up to analyze the first air, water, soil and dust samples gathered by U.N. inspectors – and test Saddam’s claims his country poses no atomic threat.

The latest in high-tech sleuthing techniques will determine the veracity of Iraq’s insistence it has abandoned its nuclear program, IAEA lab director David Donohue told reporters Tuesday.

“If there’s uranium present, we’ll find it,” Donohue said. “If a single glass marble were hidden in downtown Vienna, we could find it.”

The world will be watching what the lab finds as it runs samples under electron microscopes and through gamma and thermal ionization spectrometers, which can detect minute amounts of gamma radiation. Such radiation would be released if Iraq is working to enrich uranium for nuclear weapons.

Their findings could determine whether Baghdad is bluffing – and provide evidence the Bush administration could use to justify an attack on Iraq.

IAEA spokesman Mark Gwozdecky said the results of the first 20 to 30 samples screened at the agency’s Clean Laboratory Unit in Seibersdorf, 25 miles east of Vienna, likely will be ready by the time IAEA Director-General Mohamed ElBaradei reports to the U.N. Security Council on Jan. 27.

But Gwozdecky said the analysis, like the inspections themselves, would continue into the new year – and he made it clear the nuclear agency was resisting pressure from the United States for hastily prepared or incomplete findings.

A scientist is seen through a window in one of the laboratories of the International Atomic Energy Agency in Seibersdorf, east of Vienna, Austria. Experts with the agency will analyze air, water, soil and dust samples gathered by U.N. arms inspectors in Iraq to determine whether any traces of nuclear material are present.

“We’ll report what we know at that time,” he said. “We will not compromise the technical integrity of our work just because there’s political pressure to have results.”

Gwozdecky again called on Washington to hand over the evidence the Bush administration has repeatedly asserted it has of Iraqi weapons of mass destruction, noting the latest U.N. Security Council resolution requires member states to deliver any such information to the United Nations.

“We’re in a unique position to tell the truth,” he said.

Although the lab is equipped with technology it didn’t have when U.N. inspectors left Iraq in December 1998, its work will hinge on low-tech cotton swabs inspectors are using to swipe suspect buildings.

IAEA experts will be able to detect a trillionth of a gram of uranium or plutonium among the particles collected on the 4-square-inch swabs, Donohue said.

Inspectors wear protective gloves to gather the samples, and the swabs are double-bagged to guard against cross-contamination. It was unclear whether swabs were used when inspectors visited one of Saddam’s palaces for the first time last week, the IAEA said.

Assuming inspectors are snooping around the right places, Donohue said he’s confident the Iraqi dust will betray any attempts to hide telltale traces of radiation. “There’s no way they can clean it up so we can’t find at least a few nanograms,” he said.