Does Iran have enough uranium to make a nuclear weapon? One thing is clear — if it doesn't today, it can speed up the process substantially through work that takes little more skill than knowing how to use a plumber's wrench.The issue has come under renewed scrutiny with the latest International Atomic Energy Agency report a few days ago on the state of Tehran's uranium enrichment program, which can create both nuclear fuel and the fissile core of warheads.
It is also bound to figure in next week's deliberations of the IAEA's 35-nation board, which will focus on Iran's defiance of U.N. Security Council demands that it freeze enrichment and ease fears it seeks to make the bomb.
With the IAEA report issuing the latest figures of nuclear material Iran has processed, attention has turned to whether it could process the 1,010 kilograms — 2,222 pounds — of low-enriched uranium it is known to have amassed into enough highly enriched uranium to arm one weapon.
Some experts say 1,010 kilograms is close enough to the commonly cited minimum requirement of 1,100 kilograms, or just over 2,400 pounds, for Tehran to make a realistic attempt at making a bomb. Others say that for various technical reasons the 1,100 figure is too low, even if Iran took the unlikely step of reconfiguring its enrichment program to make weapons grade uranium under the nose of IAEA inspectors at the site. Still others are in-between, saying there are too many unknowns to make a clear prediction.
Lost in the argument is an important fact: should it be looking to make a bomb, Iran has the capacity to easily rev up production of enriched uranium to reach whatever amount it needs much more quickly than it is doing now.
It currently has close to 4,000 machines pumping out the low enriched uranium and has produced enough material to bring it at least close to 1,100 kilograms. But in a little noted observation, the IAEA report also said Tehran has 1,600 more centrifuges for enriching uranium gas feedstock on standby.
In numbers roughly tallying with the official IAEA count, Iran on Wednesday announced that 6,000 centrifuges were now "operating" at Iran's enrichment facility in the town of Natanz, including those enriching and those on standby. Iranian nuclear chief Gholam Reza Aghazadeh said Iran hopes to install over 50,000 centrifuges there over the next five years.
Iranian technicians at the vast underground Natanz enrichment plant need to do little more than hook the extra 1,500 machines to the tap feeding the already operating centrifuges. Suddenly, 5,600 centrifuges would be on line instead of 4,000. Daily output of low-enriched, or fuel-grade uranium would rise to just over 3 kilograms — 6.6 pounds — from about 2.2 kilograms now.
With 5,600 centrifuges enriching, Iran could add about 100 kilograms — more than 200 pounds — to its established stockpile within a month; or even more, considering it is setting up additional ready-to-go centrifuges every day.
Even those 100 kilograms would give it an estimated low-enriched uranium stockpile of just over 1,100 kilograms — the minimum experts believe is required to yield the 25 kilograms, or 55 pounds, of highly enriched weapons grade uranium needed to build one bomb.
However, those figures themselves are contentious.
The Federation of American Scientists argues that experts using the 25 kilogram figure fail to take into account that — even if there is that much bomb-quality uranium mixed into their stockpile — not all of it is recoverable through enrichment methods.
"The 12 to 13 kilograms they could produce would not be enough for a bomb," says FAS vice president Ivan Oelrich vice president of the FAS Strategic Security Program.
Moreover, the process of making the first uranium metal warhead from enriched uranium can lead to material loss, further reducing the amount left for a nuclear weapon.
Iran, for its part denies such aims, saying it only wants to enrich to low-level nuclear fuel grades for energy purposes. Still, with so many machines available, and more being manufactured daily, why hasn't it pressed all its centrifuges into service? Why has it only put about 200 of them to work between the IAEA's November report and the most recent one?
Even IAEA officials differ on these questions. IAEA chief Mohamed ElBaradei recently suggested Tehran's reticence was "political" — implying it was willing to wait on expanding enrichment in exchange for better relations with the new U.S. administration, which has pledged to break with decades of snubbing Iran and talk directly with it.
But some of his technical staff say the reason may have more to do with technical problems at Natanz. They note frequent breakdowns of centrifuges and say the Islamic Republic needs to have at least some ready to substitute for these.
Whatever the reasons, the agency is united in dismissing recent suggestions that Tehran had tried to hide the true amount of low-enriched uranium it was producing by purposely underestimating output between once-yearly IAEA inspections of amounts.
It turns out that the estimates were about a third less than the actual amount of 1,010 kilograms. Still agency officials say the mistake appeared unintentional and within limits of error inherent in such guesswork.
And, as usual, in Iran's favor. Again.
"The agency has no reason at all to believe that the estimates of the low enriched uranium produced ... were an intentional error by Iran," according to IAEA spokeswoman Melissa Fleming. "Iran has provided good cooperation on this matter and will be working to improve its future estimates."
Even diplomats from Western nations accusing Iran of harboring nuclear weapons ambitions agree that — at least this time — Tehran is not guilty of deception.