Iranian breakout timelines in a comprehensive deal

Richard Nephew

The possibility of a rapid Iranian nuclear breakout has long consumed the United States government, its international partners, and interested observers outside of government. Iran’s acquisition of nuclear weapons would fundamentally threaten states throughout the Middle East and beyond, as well as upset global nuclear nonproliferation efforts. Moreover, as a benchmark for a nuclear deal with Iran, breakout timelines are usefully quantitative, permitting ready comparisons between scenarios.

However, even a useful construct can be taken too far. For starters, most breakout scenarios focus on the time needed for Iran to acquire enough nuclear material of sufficient potency for one nuclear weapon. This over-simplification of breakout ignores the time required to make that nuclear material usable in a bomb—gas or powdered uranium doesn’t do much good—and also assumes that Iran would be mad enough to risk military strikes in order to produce one nuclear weapon. Nuclear deterrence theory has long taught that the most precarious situation for any nuclear weapons aspirant is the possession of one rudimentary device, as the state automatically becomes a target for preemptive military strikes without having a secure second strike capability. Still, whether a nuclear breakout with one bomb’s worth of nuclear material is realistic, it is the metric of merit in today’s debate.

The question then becomes whether the proposed nuclear deal with Iran would improve our present situation, and for how long. Some have argued that, even if the nuclear deal stops an imminent breakout, it is only delaying Iran’s inevitable nuclear rise. Others, such as University of Texas professor Alan Kuperman, in a New York Times op-ed have alleged that the “basic science and math” underlying the Obama administration’s approach to preventing the uranium-path to a nuclear weapon is wrong.

Though I disagree vehemently with the air of predestination that seems to grip speculation on Iran’s unstoppable sweep to nuclear arms, this blog post will focus on the latter line of argument.

How many centrifuges in a breakout?

Kuperman argues that it is “laughable” that in the event of a breakout, Iran would use only the 5,060 centrifuges permitted under the framework for a deal announced in April 2015 rather than also use the “roughly 14,000 additional centrifuges that Iran would be permitted to keep mainly for spare parts.” I agree, but Kuperman fails to note that it would take considerable time to install, balance, and spin thousands of centrifuges; this factor plays a significant role in the Administration’s judgment that a one-year breakout time is achievable in part through the reduction of installed centrifuges even if the extra are stored. If you go too fast or engage in sloppy mechanical work, centrifuges tend to break in epic fashion.

Iran has installed centrifuges at a fast clip before. From November 2011-2012, the Iranians installed slightly more than 5,000 centrifuges and from November 2012-2013, they installed an additional 6,000. The pace varied considerably during this period; Iran at times installed thousands of machines in months and at other times, only hundreds. But even during this two-year phase of rapid expansion, Tehran did not install 14,000 centrifuges or even 13,000 centrifuges (taking into account that, beyond its 5,000 operational centrifuges, roughly 1,000 centrifuges will be installed but not operating).

Some will argue that Iran may have been hampered by sanctions from being able to construct that many centrifuges (which the storage concept would avoid) or that a breakout scenario will be different – Iran would seek to install those centrifuges more quickly. However, such frenetic activity almost certainly would be detected through inspections and transparency measures. Even the sharpest of the IAEA’s critics would have to concede that an extra 13,000 centrifuges would be hard to miss. Launching installation activity, or even ejecting inspectors, would be quickly detected, prompting an immediate response.

Others (such as Heinonen and Henderson in this piece published by the Washington Institute for Near East Policy) have noted the difference in efficiency calculations that can be derived based on past performance of Iran’s IR-1 centrifuges, arguing that Administration predictions may be off. It is fair to say that operational experience has varied over the lifetime of these centrifuges. Though some may predict more efficient operation during the comprehensive plan of action’s lifetime, I believe it is more reasonable to believe that Iran’s desire for generating a fait accompli with respect to its nuclear program (such as by establishing a large stock of low enriched uranium) would have motivated Iran not to hide the true operational significance of its centrifuges to this point or at least by any great degree. As such, assuming an average performance of one “SWU per year” (the technical measure of centrifuge efficiency) seems reasonable and is in keeping with a one-year breakout timeline predicted by the Administration, as well as Iran’s eight year operational enrichment history.

Kuperman also advocates that Iran’s stock of old IR-1 centrifuges must be destroyed to prevent a rapid breakout. In my view, this would be the worst thing that we could do. Such a demand would elicit Iranian counter-demands for a production infrastructure to replace any centrifuges that break down through normal wear and tear. This, in turn, would complicate the work of intelligence analysts and international monitors who will be seeking to find any evidence of covert enrichment work. The signals of illicit Iranian work would be obscured if there is also a legitimate, potentially large-scale, IR-1 centrifuge production infrastructure preserved. As others have noted, it is a covert program that is to be feared the most, rather than the declared program. We will need all the tools at our disposal (especially robust transparency and monitoring access to undeclared sites) to combat such a threat. Given this, destroying Iran’s stockpile of centrifuges may make for good television footage, but it would make for dreadful policy.

And what about nuclear material?

Kuperman also criticizes the expected agreement’s plan for Iran’s enriched uranium stockpile, suggesting that the “deal would appear to also permit Iran to keep large amounts of enriched uranium in solid form (as opposed to gas), which could be reconverted to gas within weeks, thus providing a substantial head-start to producing weapons-grade uranium.

I would agree—if this assertion was accurate. But I do not believe that it is. While there is no deal yet and any details that have emerged remain shrouded in imprecision, public statements by both sides after Lausanne—in both the joint statement issued by Tehran and the P5+1 as well as the U.S. Factsheet published by the Obama administration—established that the agreement will restrict Iran’s total, available stockpile of enriched uranium of both gas and oxide forms.

The joint statement issued in Lausanne offers only modest details. Though vague, it does endorse the concept that Iran accepts— it was a joint statement— that its stockpile will be limited for a specific duration.

The U.S. Factsheet— which was a unilateral document— goes farther, saying that “Iran has agreed to reduce its current stockpile of about 10,000 kg of low-enriched uranium (LEU) to 300 kg of 3.67 percent LEU for 15 years.” Though more specific. But, at the same time, it does not offer any explicit information about the phase of the material in question: solid, liquid or gas. Consequently, on the surface, it would seem to capture any LEU regardless of form.

This has led to confusion, in part because the term is loosely utilized in the 2013 U.S. Factsheet on the Joint Plan of Action (JPOA) to describe solely LEU gas (and, for this, the explanation is mundane: as a factsheet finalized at 2 in the morning, its technical precision was not as it should have been. Mea culpa. Fortunately, other details in that factsheet and subsequent events have helped to explain what was meant.)

But, while confusion has resulted, it shouldn’t have. The key fact is the number 10,000 kilograms. Iran does not have 10,000 kilograms of low enriched uranium gas and never has. Per the Joint Plan of Action (JPOA), Iran was forced to cap its stockpile of uranium gas at 7,650 kilograms. As discussed separately, though Iran has had more than 7,650 kilograms of enriched gas at various times, it has also acted to bring that number down to below the 7,650 level by the deadlines it has faced under the JPOA.

So, if Iran never had 10,000 kilograms of enriched uranium gas, then to what does this refer? A careful reading — and a bit of math — permits one to extrapolate from the International Atomic Energy Agency’s latest report on Iran’s uranium stockpile (released in early June) that this includes all of the LEU gas and oxide known to the IAEA in Iran. It does not include LEU in fuel (of which there is tons at Bushehr and have been since December 2007) and instead focuses on the more-or-less freely available LEU in the country.

For the future, precise language will be needed. But, this is— in the end— why a comprehensive document is being written.

What about the rest of its uranium?

A real practical problem remains with respect to how Iran will achieve the 300 kilogram cap, particularly given that it exists in a variety of forms, phases, and enrichment levels. But, there are solutions, each of which will vary depending on the kinds of materials involved:

  • Dilution: For the majority of Iran’s LEU stock, dilution back to natural levels is a straight-forward, simple procedure. Of the approximately 10,000 kilograms (which will be a bit more whenever the comprehensive deal is agreed, given ongoing enrichment), around 70 percent can be dealt with in this fashion. Once at natural levels, it will be far less easily used in a breakout scenario, since most of the work needed to “enrich” uranium is in the initial effort.
  • Conversion: Some of the Iranian material, though, is currently being converted into oxide. Iran has had trouble with its conversion plant and some of the material is therefore stuck in what are called “Intermediate compounds.” These compounds, as well as the oxide already manufactured, could be brought back into gas form and then subsequently diluted. This may be more complicated with some compounds than others and Iran may need help in doing it, but this is achievable, if time-consuming. This would account for most of the rest of Iran’s enriched uranium stockpile.
  • Shipping out: Of course, Iran could short-circuit this whole effort by simply agreeing to ship the material out, whereupon it would become invulnerable to future Iranian use. Though Iran has claimed this option is off of the table, they have claimed similar things in the past. Negotiations and technical realities could trump political concerns here.

What’s left after that is either nuclear fuel (which is not a credible problem) or scrap material. Scrap material, such as poorly manufactured fuel for Iran’s Tehran Research Reactor, is important, as it contains 20 percent enriched uranium. But, it can also be addressed, most easily by Iran agreeing to ship it out in exchange for completed fuel or sold for its uranium content.

And, of course, needless to say that all of this material would also be under international monitoring and any attempt to divert it would — like with the stored 14,000 centrifuges — be quickly detected.

And what about the amount of material Iran needs for a bomb?

Kuperman’s most salient argument is that Iran may require less highly enriched uranium (HEU) than the IAEA defined “significant quantity” of 25 kilograms of 90 percent HEU. Outside experts have long contended than a bomb is possible with less than this amount. But, considering that an Iranian breakout would also be its first bomb, Iran would likely wish to go for certainty rather than “hope” a smaller design would work. In my view, it is therefore not likely that they would attempt to short-change the breakout bomb for which they would have risked so much.

However, even a smaller nuclear device would not solve Iran’s real breakout dilemma. The long-pole in the tent for an Iranian breakout would be the enrichment of the larger stock of LEU still needed to produce a bomb.

Deal or no deal

It is precisely this problem that the comprehensive deal being worked on in Vienna seeks to address and, according to the U.S. Factsheet, considerable progress has been made. In my view, a deal along the lines of what the U.S. Factsheet outlined on April 2 is technically feasible and a material improvement over the status quo and certainly over the scenario of a breakdown of talks and the Joint Plan of Action (which many of the critics of a comprehensive agreement also condemned variously as unworkable or a disaster but now support).

Opponents of a nuclear deal with Iran appear to feel differently. Though producing enough HEU for a bomb would not take Iran long with 20,000 installed and operating centrifuges and more than 10,000 kilograms of LEU— as well as the bomb-production plant at Arak, spewing out 1-2 weapons’ worth of plutonium per year— at least some opponents seem to believe that this situation is more manageable than a scenario in which Iran has less than 30 percent of its current installed centrifuges and 3 percent of its enriched uranium stockpile. Even my math is basic enough to understand how laughable that really is.