Iran nuclear program: Clock is ticking as uranium collects

Iran's steady production of low-enriched uranium is a clock that is ticking away as Tehran develops its nuclear program.

Every day, the whirling centrifuges at the Natanz Fuel Enrichment plant produce about 2.75 kilograms of the stuff, according to International Atomic Energy Agency data.

Day after day, this amount is added to Iran's existing stockpile of low-enriched uranium (LEU), estimated by the US to total about 1,600 kilograms.

This material can be used as the feedstock for weapons-grade uranium. That is why US experts worry about it so much – and why the West wants Iran to ship most of it abroad, where it can be converted into a much less dangerous form of reactor fuel.

Iran's enrichment program "is the pacing element in determining when [Iran] would be capable of making a nuclear weapon," said Paul Pillar, a former US intelligence officer who is now a professor of security studies at Georgetown University, at a recent Arms Control Association seminar on the Iranian nuclear challenge.

Right now it is far from a sure thing that Iran will agree to the US-backed proposal that it send most of its LEU to Russia for processing.

Iranian officials have sent mixed signals on the proposal. On Monday, the head of the UN nuclear agency urged Iran to clarify its response.

Addressing the UN General Assembly, Mohamed ElBaradei said "a number of questions and allegations relevant to the nature" of Iran's nuclear efforts remain. Dr. ElBaradei, who is stepping down after 12 years as the IAEA's chief, called for confidence-building measures on all sides.

"I therefore urge Iran to be as forthcoming as possible," he said.

The US and many other countries are worried that Iran is bent on obtaining nuclear weapons. Tehran insists its nuclear program is for peaceful purposes.

Iranian President Mahmoud Ahmadinejad said on a government website in regards to the current negotiations that Iran "looks at the talks with no trust."

The problem with Iran's low-enriched uranium, from the point of the view of the US, is that it can be turned into bomb-grade material relatively easily.

Western experts worry about a breakout scenario, in which Iran would openly race to further enrich the LEU into weapons-usable high-enriched uranium (HEU).

As of February, Iran had produced enough low-enriched uranium to serve as the feedstock for fissile material for one bomb, according to David Albright, a former weapons inspector and president of the Institute for Science and International Security (ISIS).

At 2.75 kilograms a day, Iran by February 2010 will have produced enough LEU to serve as feedstock for two bombs, according to Mr. Albright's calculations.

To produce weapons material, Iran would have to feed its LEU into centrifuges again.

"This could be accomplished within three to six months at either the Natanz facility or in a clandestine gas centrifuge facility," noted a recent ISIS analysis.

The newly revealed facility at Qom, for instance, could have been intended to serve as just such a secret plant, according to some Western experts.

The US-sponsored export plan calls for Iran to ship 1,200 kilograms of its LEU abroad for conversion into fuel rods capable of running a small research reactor in the Tehran suburbs that produces medical isotopes.

If Iran agrees to this plan, the stockpile left behind would not be large enough to produce a weapon's-worth of HEU.

But Iran likely would continue to produce its low-enriched uranium product at Natanz, day by day. Eventually, the stockpile would again reach a critical point.

The US intelligence community officially estimates that Iran will be technically capable of producing enough HEU for a weapon at some point between 2010 and 2015.

But that is not the same thing as saying an Iranian nuclear weapon would suddenly appear, pointed out Greg Thielmann, a former intelligence officer and current senior fellow at the Arms Control Association.

Engineering a working weapon, and a working ballistic missile or other sort of delivery vehicle, would remain difficult problems, pointed out Mr. Thielmann.

"We hear a lot about red lines being crossed and time running out, yet measured against the worst-case assumptions about an Iran seeking to develop and deploy nuclear weapons as soon as possible, one conclusion is hard to avoid: Time lines for the earliest possible arrival of an Iranian nuclear threat are actually being extended outward," said Thielmann at the Arms Control Association seminar.

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