The latest IAEA report on Iran’s nuclear program has been released [IAEA 28 Aug 2013]. The Washington D.C. think-tank called ISIS (Institute for Science and International Security) has published an analysis of that report [ISIS 28 Aug 2013].

My thoughts on the subject of Iran’s nuclear program in past posts are here. I have written many posts on the dangers of Iran’s nuclear program, and their continuing progress toward obtaining nuclear weapons. Now, given the latest information from the IAEA, this progress has recently accelerated. Iran has now installed over 1,000 of the new, more advanced, uranium enrichment centrifuges (IR-2m), and over 1800 additional first generation (IR-1) centrifuges. The total number of installed centrifuges at the two enrichment facilities (Natanz and Fordo) is about 19,500. Iran now has a vast capability to enrich uranium to weapon-grade purity (greater than 90%).

However, thousands of these centrifuges — nearly half — lie idle; they are not enriching uranium at all. And this has been the case for many months, over the course of several IAEA reporting periods (every 3 months). The cost to install and set-up these centrifuges, especially in the face of severe economic sanctions and import restrictions is very high. And yet they are not being used. Let’s consider why that is.

Iran needs a certain quantity of uranium gas, enriched to 20% of the U-235 isotope, in order to jump quickly to the next step, making 90% U-235 gas for use in nuclear weapons. Past ISIS estimates on the amount of 20% gas needed ranged from 180 – 220 kg (ISIS 8 Oct 2012) to 300 kg (ISIS 31 July 2013). However, the most likely (non-covert) breakout scenario is that of single cascades at Natanz and tandem cascades at Fordo, which requires at least a 240 kg stockpile of 20% U-235 gas. This scenario is most likely because a lower stockpile would necessitate reconfiguring many thousands of Natanz centrifuges to tandem configuration. Alternately, Iran could breakout solely using the tandem centrifuge cascades at Fordo, but the process would take twice as long (2 months instead of 1). Single cascades at Natanz together with tandem cascades at Fordo provides the quickest breakout (1 month) with the least stockpile of gas. And that is why most observers have settled on 240 kg of 20% enriched uranium gas as the “red line” that they wish to prevent Iran from crossing.

Currently, Iran has 185.8 kg of 20% U-235 gas. However, they have produced a total of 372.5 kg of 20% U-235 gas. Thus, if Iran had held on to all the 20% U-235 that it has produced to date, they would be well beyond the 240 kg red line. The total of over 370 kg of 20% U-235 is enough enriched uranium, if further purified to weapon-grade (90%) to make at least several low-yield nuclear weapons. But that total of about 370 kg has been reduced to 185.8 kg by the diversion of 185.1 additional kg of 20% U-235 gas to a Fabrication Plant at Esfahan in Iran that turns the gas into uranium oxide metal plates. About half of the 20% U-235 produced by Iran’s nuclear program has been turned into a form that makes it unusable for nuclear weapons (unless converted back to gas and further purified).

Iran has spent billions of dollars and has endured harsh economic sanctions for many years, all to pursue nuclear weapons. I don’t believe that Iran would take half of its 20% U-235 gas and essentially throw it away by converting it to a metal oxide. What is more likely, in my opinion, is that Iran has deceived the IAEA inspectors. Iran could have obtained uranium oxide plates from China or another nation. And they could have moved most of that 185.1 kg of 20% U-235 gas either to a hidden stockpile, to await a future breakout, or to a hidden (covert) uranium enrichment plant.

ISIS has repeated cautioned that Iran might be in the process of constructing a covert uranium enrichment plant, in addition to the two known plants at Natanz and Fordow. In their 30 July 2013 report, in a subsection entitled “A Secret Site?”, ISIS wrote:

ISIS judges that if Iran has one, it has likely not yet finished a secret centrifuge facility composed of about 2,000-3,000 advanced centrifuges, similar in size to the deeply buried Fordow centrifuge site. Such a facility could produce sufficient weapon-grade uranium relatively quickly if the centrifuges worked well. So far, few experts believe that Iran has finished such a plant. But is Iran building one?

That question is much harder to answer, but there are reasons to conclude the Iran could now be building a new centrifuge plant, based primarily on Iranian officials’ past statements. Iran has built each of its centrifuge plants in secret, revealing them when caught, a fact well documented by the IAEA. It secretly constructed the Natanz centrifuge site, the Kalaye Electric centrifuge research and development plant, and the deeply buried Fordow centrifuge facility. [ISIS report]

If Iran has such a third covert uranium enrichment facility, it need only produce enough weapon-grade uranium for two or three low-yield nuclear weapons. The 185 kg of 20% U-235 is sufficient for that purpose. If that gas was diverted to a third covert facility, Iran could already be well on the way to making nuclear bombs.

Once 2 or 3 bombs are produced, Iran could disclosed their existence to the world, and threaten to use them in order to prevent a military strike by the U.S. or Israel against its non-covert nuclear facilities. Those facilities would then be used to make as much weapon-grade uranium as possible, as quickly as possible, sharply increasing the number of nuclear weapons possessed by Iran. A non-covert breakout by Iran using all of its nearly 19,500 centrifuges (plus any other centrifuges that are in a covert facility) could produce many nuclear bombs per year.

In my opinion, this two phase breakout strategy (phase one, covert; phase two, non-covert) is the most likely explanation for two of the most perplexing decision by Iran: (1) the decision to convert half its precious 20% gas into metal oxide, and (2) the decision to install but leave idle many thousands of enrichment centrifuges. Of the nearly 19,500 centrifuges installed, only about 10,000 are in operation. Thousands of centrifuges have sat idle for many months, despite being ready to work according to IAEA inspections and reports.

What is Iran waiting for? Why would a nation spend billions on centrifuges and uranium gas purification, only to leave almost half the centrifuges idle? They cannot ramp up production of 20% uranium gas, because if they pass the 240 kg red line (or even come close to it), the U.S. or Israel might destroy their entire multi-decade nuclear program with a few days of bombings. But if they produce just 2 or 3 nukes covertly, they can threaten the U.S. and Israel with nuclear retaliation, and then begin a non-covert breakout using their nearly 20,000 centrifuges.

One reason for leaving so many centrifuges idle is that they can more quickly be ramped up for the production of weapon-grade uranium (90% purity). The centrifuges are connected in a series, and each series of about 170 centrifuges is called a cascade. If the cascade is filled with low enriched uranium, then to begin a breakout, that gas needs to be emptied out. And the settings on the cascade need to be changed to account for the different level of enrichment of the new feedstock. Leaving a large number of centrifuges ready to go, but empty of gas, allows for a quicker start to any breakout.

So I believe that the 185.1 kg of 20% U-235 gas that was supposedly converted to oxide metal was instead diverted to a third covert facility. Iran will soon have enough weapon grade uranium for a few nuclear bombs, and then the large-scale public breakout will begin.

Iran might also be obtaining 20% U-235 gas from its current non-covert enrichment facilities by skimming some of the gas from the centrifuges, and reporting a lower enrichment output than is actually occurring. ISIS has repeatedly stated that Iran’s centrifuge cascades show “consistently lower enrichment output” than would be expected. The IAEA does not have cameras in Iran’s enrichment facilities, so they rely on spot inspections every week or two. It would be entirely tenable for Iran to remove some of the gas while inspectors are absent, and then misreport the total gas produced to the IAEA.

By means of these two sources, Iran might have already moved enough 20% U-235 gas to a third covert facility for a nuclear breakout.

by
Ronald L. Conte Jr.
Roman Catholic theologian and
translator of the Catholic Public Domain Version of the Bible.