Strategic Comments - Volume 14, Issue 10 - December 2008

Can Obama re-engage Iran: Iran's nuclear capability

On 26 November, Iran announced it was running more than 5,000 centrifuges at the Natanz uranium-enrichment facility. A week beforehand, the IAEA reported that 3,800 centrifuges had been operating for some time and another 2,100 would be ready by the end of 2008. Iran's announcement, if true, means that half of the latter centrifuges are already running.

The IAEA also noted preparatory work was under way for an additional 9,000 centrifuges, which would bring the total to 15,000, albeit at some unspecified future date. The centrifuges in operation today are P-1 (Pakistan first-generation) models, but Iran continues to experiment with more efficient later-generation centrifuges.

As of 7 November, Iran had produced 630kg of low-enriched uranium (LEU) of the 3.5–5% enrichment level appropriate for reactor fuel. This led the New York Times to claim that Tehran had enough fissile material for a nuclear weapon, if the LEU were enriched.

This is incorrect, though, because the IAEA measured Iran’s output in the form of uranium hexafluoride (UF6), meaning one-third of the weight was fluorine. With no process losses, at least 1,000kg of 4%-enriched UF6 is needed to produce enough highly enriched uranium (HEU) for a weapon (using the standard of 25kg of 90%-enriched uranium as the critical mass). But countries new to the manufacturing process would need at least 1,200kg of LEU. With Natanz producing 2.2kg of LEU a day, Iran’s stockpile should approach this range in mid 2009.

Enriching LEU to HEU, however, would alert IAEA inspectors to Iran’s intentions. The international community would then have some time to react. It would take one to two months for Iran to reconfigure the cascades at Natanz, then about 40 days to re-enrich the accumulated LEU to HEU. It is unknown how long it would then take Iran to reconvert the gaseous HEU to metal and fashion a weapon from it, but an educated estimate would put that at six months or more.

US intelligence has not changed its conclusion last year that Iran halted weapons development in 2003 and had not resumed it as of mid 2007.

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