Our guest blogger is Andy Grotto, a Senior National Security Analyst at the Center for American Progress Action Fund.
Here’s the back-of-the-envelope math for all you geeks out there:
— Iran possesses an estimated 630 kg of low-enriched uranium (LEU) containing 3-5% of the fissile isotope U-235. Uranium enriched at this level of U-235 purity is suitable for use in energy reactors. But uranium enriched to 90% U-235 (or greater) is considered weapons-grade highly-enriched uranium (HEU).
— Iran could acquire weapons-grade HEU by further enriching its existing LEU stockpile, which contains somewhere between roughly 19 and 30 kg of U-235. This translates to around 21 to 33 kg of weapons-grade HEU.
— Both the IAEA and the U.S. DOE say 25 kg of weapons-grade HEU is enough for one bomb; many experts believe the threshold is much lower, perhaps even half that.
Thus, with its existing stockpile of LEU, Iran is well within range of having sufficient feed for one nuke.
This is more of a political milestone than a technical one — there is no evidence to suggest that Iran has an actual bomb or the highly-enriched uranium needed to make one just yet. Iran would still need to further enrich its LEU, and there’s a good chance that the IAEA would eventually notice this if it took place in Iran’s known enrichment facilities. Moreover, Iran would still need to make the actual warhead and develop a suitable delivery mechanism. Finally, having a single bomb is a long way from having a credible arsenal.
But make no mistake: Iran achieved this milestone on President Bush’s watch.