Seven problems with John Kerry's Iranian nuclear clock

US officials have instead proposed that the SWU cap be enforced by limiting the amount of uranium hexafluoride (UF₆) gas that is fed into the centrifuges. But this begs the question of how quickly Iran can ramp up production of UF₆ once it begins a breakout, and what new, untested disablement regime will be needed to slow this process.  Elaborate mechanisms to limit gas supplies simply cannot provide the same degree of confidence as dismantling the centrifuges they feed into.

Wrong Enrichment Plant

However much the limited centrifuge, LEU, and SWU caps the Obama administration has in mind may extend Iran’s nominal breakout time, this figure won’t mean much in a contested breakout.  Iran isn’t likely to get very far trying to produce fissile material for a bomb at its main Natanz enrichment facility, where all post-agreement enrichment is to be carried out – the site is too vulnerable to outside air strikes that would likely follow such brazen defiance of the international community.

A contested breakout can only succeed at Iran’s smaller Fordow plant, which is buried sufficiently deep underground to likely survive Israeli, perhaps even American, air strikes. This route to the bomb will take longer to achieve than an uncontested breakout at Natanz.  Since Iran has pledged to discontinue industrial enrichment at Fordow once an agreement is signed, it will first have to get centrifuges back up and running, and even then its output will be a fraction that of Natanz.  

According to Albright, a full complement of 3,000 IR-1 centrifuges at Fordow would take about a year to produce a bomb’s worth of WGU using only natural uranium, and “significantly” less if a substantial quantity of LEU is available (which, as underscored above, will likely be the case) or if more advanced centrifuges are available for installation (ditto). But time doesn’t matter as much when the centrifuges are spinning deep underground.

The more interesting question is how long it takes to restart and ramp up enrichment at Fordow – or at least move centrifuges and other vital equipment inside the subterranean fortress.  That is when the process is most vulnerable to outside disruption. 

Naturally, the Iranians are adamant that this timeline be as short as possible.  They have refused to demolish, strip down, or even close the Fordow bunker, insisting that it remain in operation as “research and development and back-up site for Natanz." After initially insisting that Fordow be shut down completely, the Obama administration has agreed that Iran will merely be required to suspend enrichment and accept unspecified provisions that "constrain the ability to quickly resume enrichment there," in the words of one senior American official.

But the timeline for stage one of a Fordow-centered breakout is difficult to quantify, let alone delimit, reflecting such myriad factors as the number and competency of Iranian scientists and technicians, how much they’ve drilled, the availability of relevant equipment, etc. – all of which are sure to improve for Iran in the years ahead.

Moreover, Iranian actions during the vulnerable stage of a Fordow breakout aren’t likely to be regarded as a clear casus belli by the international community.  While this path to the bomb can be readily obstructed when centrifuges are being moved back into the facility, simply moving equipment around in violation of treaty isn’t likely to trigger decisive external military intervention.  Just to be sure, Iranian clerics could simultaneously summon thousands of women and children to the site to act as human shields.  Named after a nearby village known for having the largest martyrdom rate during the Iran-Iraq war, Fordow would be ideally suited for such a stunt.

Although details concerning the status of Fordow remain unresolved, it’s clear that the facility will remain operational under a prospective agreement, subject to untested technical provisions to obstruct the rapid resumption of industrial enrichment, and its status as a symbol of Iranian resistance thus formally consecrated.

Time Isn’t Everything

Finally, Kerry’s breakout time argument – and the Obama administration’s Iran counter-proliferation policy as a whole – is predicated on the widespread, but hardly self-evident, assumption that having as much time as possible to stop a future breakout in progress is the touchstone of a “good” agreement.