Seven problems with John Kerry's Iranian nuclear clock

Even a perfectly functioning disablement regime won’t suffice unless the international community has an accurate count of Iran’s centrifuges, particularly those it possesses beyond the 19,466 installed at its Natanz and Fordow enrichment plants.  The latter include around a thousand, non-operating IR-2m centrifuges at Natanz, which have an average enrichment output three to five times greater than the IR-1. Olli Heinonen, the former deputy chief of the International Atomic Energy Agency (IAEA), recently said that Iran could have thousands of additional IR-2m centrifuges, or the components for assembling them, stored outside of these declared facilities.

As Lee Smith has warned, there’s little indication that the Obama administration is demanding the kind of invasive inspection regime that would be needed to verify Iran has no appreciable stockpile of undeclared centrifuges.  Given the administration’s unwillingness to demand full disclosure of past nuclear weapons research, this is unlikely to change.

Limitations of an LEU Cap

Although the Obama administration initially proposed a limit of 1,500 IR-1 centrifuges, it is widely reported to have agreed to let Iran operate somewhere in the neighborhood of 4,000 to 6,500 IR-1 centrifuges under the terms of a prospective agreement, and may yet settle for an even higher number. There are only two ways to produce a nominal breakout time of one year with this many centrifuges running.

The first is to reduce the amount of LEU the Iranians can accumulate at any one time.  LEU, as Frank von Hippel and Alex Glaser put it, is essentially “stored enrichment work.” Reducing LEU supplies below the roughly 1,000 kg needed to produce one SQ  would lengthen nominal breakout time by forcing the Iranians to enrich some quantity of natural uranium all the way up to WGU.  According to ISIS calculations, for example, 6,000 IR-1 centrifuges and 500 kg of LEU would correspond to a one-year breakout time.

U.S. officials have proposed achieving this by requiring Iran to either convert the LEU normally produced by its centrifuges into an oxide form (unlikely, as this can be reversed in a matter of months) or have it shipped to Russia, in exchange for specialized fuel rods for its Bushehr power plant that cannot easily be weaponized.

The problem with a many-centrifuges-little-LEU cap is that it requires Iran to continuously surrender or reprocess material it already possesses for its extended breakout time to remain constant.  But suppose it simply stopped doing this? If the Iranians were going to attempt a breakout, they would likely begin by “feigning problems in the conversion plant or delays in transporting” the LEU, notes ISIS President David Albright. By the time it would be unmistakably clear to the outside world that a breakout was underway, they would have substantially exceeded whatever LEU cap is established.  With a few-centrifuges cap, a “creepout” is impossible, as Iran would have to install more centrifuges to narrow its breakout time, not merely fake an industrial accident.

The Iranians could also stop surrendering LEU, while otherwise abiding by a prospective agreement, as a means of wresting additional concessions from the West, calculating that no one will start a war in response to inaction.

Moreover, having a larger number of centrifuges in operation would make it easier for Iran to build centrifuges in secret and hide illicit procurements for a covert facility, particularly if the Obama administration drops the longstanding P5+1 demand for substantial curbs on centrifuge research and development. Iran has built and tested prototypes of advanced centrifuges with even higher enrichment capacities than the IR-2, most notably the IR-8, with an annual SWU capacity anywhere from seven to 16 times that of the IR-1. Because far fewer are required to produce a given output, advanced centrifuges allow for the construction of smaller, harder-to-detect clandestine enrichment facilities.

Limitations of an SWU Cap

Unfortunately for the Obama administration, the Iranians have insisted on keeping such a high number of centrifuges in operation that a practical LEU cap alone can’t extend Iran’s nominal breakout time to a year.   In recent months, U.S. officials have warmed to an Iranian proposal to instead cap the net output of its centrifuges, measured in separative work units (SWU).  Several prominent NGOs endorsed an SWU cap last year, including the Arms Control Association and the International Crisis Group.

The Iranians initially proposed that the SWU cap be enforced by reducing the rate of spin on the centrifuges.  But this process can be quickly reversed.