The Arms Control Association’s Greg Thielmann notes that there was a decrease in Iran’s stockpile of 20 percent-enriched uranium, as indicated by the latest International Atomic Energy Association (IAEA) report about Iran’s nuclear program, but did you know that? The P5+1 has heavily focused on Iran’s highly-enriched stockpile because it poses “a much more rapid “breakout” option for Iran” and yet the reduction, as well as “the absence of evident progress by Iran on expanding the number of its advanced centrifuges in operation”, says Thielmann, has been under-reported in mainstream press:
The IAEA confirmed in January that Iran had begun producing 20 percent enriched uranium at the deep underground (and less vulnerable) facility at Fordow. Former IAEA Safeguards Department chief Olli Heinonen noted then that: “At current production rates, Iran can expect to have a stock of 20 percent enriched uranium of around 250 kg by the end of 2012…”
Yet, the IAEA’s latest report counted only 91.4 kg in the UF6 stockpile at this level, lower than the 101 kg reported by the agency in May. This decrease is explained by Iran’s continuing withdrawal of 20 percent enriched UF6 for conversion into U3O8 in the form of metallic fuel plates for use in the ageing Tehran Research Reactor (TRR), which makes medical isotopes.
In spite of the growth in the gross amount of 20% enriched uranium produced during the latest quarter, Iran was no closer to being able to achieve sufficient weapons grade uranium for a bomb. Importantly, uranium in the form of fuel plates cannot easily be converted back into the gaseous form required for further enrichment. Even though still enriched to 20 percent, it is essentially no longer available for diversion into a military program.
An equally important detail from the IAEA report is the absence of evident progress by Iran on expanding the number of its advanced centrifuges in operation. More advanced centrifuges could enrich much more efficiently than the older IR-1 model now installed at both the underground fuel enrichment facilities at Fordow and Natanz. The more advanced IR-2 and IR-4 centrifuges are still limited to the three cascades that have been in operation for some time at the above-ground Pilot Fuel Enrichment Plant at Natanz.