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Why Iran’s growing uranium stockpile won’t derail a nuclear deal

Richard Nephew

Over the last two days, much has been made of the apparent inconsistency of the requirements of the Joint Plan of Action (JPOA) between the P5+1 and Iran, and the IAEA’s latest report on Iran’s enriched uranium stocks. Some have argued that this inconsistency augers poorly for Iran’s ability to implement a future comprehensive deal, which the U.S. fact sheet on the parameters of a Joint Comprehensive Plan of Action (JCPOA) states would include a reduction of Iranian enriched uranium stocks down to 300 kilograms. They have also noted that Iran has slowed in fulfilling its remaining obligations with respect to its more sensitive 20 percent enriched uranium stocks.

Fortunately, there is more smoke than fire in this story.

Technical baseline: Iran’s commitments under the interim nuclear accord

Let’s unpack the details a bit and place them in context.

Under the JPOA, Iran agreed to do two major things with its enriched uranium stockpile.

1. First, Iran agreed to cap its stock of up to 5 percent enriched uranium to the amount it had at the time of implementation of the JPOA or approximately 7,650 kilograms.[1] Since Iran would continue enriching uranium, Iran agreed that any produced in excess to this cap would be converted from gas form (UF6) to oxide form. While UF6 can be readily reintroduced into centrifuges, other chemical forms cannot be. This is a simple physical issue: you can’t spin powder in centrifuges or, anyway, with any practical results. You have to spin gas. The United States and the P5+1 partners insisted that any enriched uranium produced in Iran be capped in UF6 form at the amount in Iran at the time of implementation of the JPOA.

2. Second, Iran agreed to dilute half of its stock of 20 percent enriched uranium and to convert the other half into oxide, for the same reasons as with the up to 5 percent enriched uranium. Iran subsequently agreed in July 2014 to turn its residual, converted 20 percent material into fuel for the Tehran Research Reactor (TRR). Taken together, the JPOA solved the problem of Iran’s 20 percent enriched uranium stockpile, which Israeli Prime Minister Benjamin Netanyahu made famous with his “Wile E. Coyote” sketch at the UN General Assembly.

What the IAEA has reported on Iran’s continuing enrichment

The IAEA’s latest report spoke about both issues.

With respect to Iran’s up to 5 percent enriched uranium, the IAEA reported that the stock of Iran’s enriched uranium in gas form (for technical people out there, uranium hexafluoride or UF6) was now 8714.7 kilograms. The IAEA also reported that Iran’s stock of up to 5 percent enriched uranium in powder form (for technical people out there, uranium oxide or UO2) now stands at 151 kilograms. The IAEA noted that the rest of Iran’s up to 5 percent enriched uranium is now in “different states of the process” to convert it from gas to oxide form. Added up, and Iran’s overall up to 5 percent enriched uranium stock is around 11,500 kilograms.

With respect to Iran’s 20 percent enriched uranium, the IAEA reported that Iran’s production of TRR fuel plates is continuing, resulting in one experimental fuel assembly (an assembly is a collection of individual fuel plates) and 34 TRR-specific fuel assemblies.

How Iran is handling up to 5 percent enriched uranium under the JPOA

Some have leapt upon the IAEA’s information that suggests the up to 5 percent enriched uranium cap has been breached to argue that Iran is in breach of the JPOA. They have also noted that Iran’s enriched uranium stockpile is some 20 percent higher than it was in November 2013, arguing that although the administration has been claiming to have frozen the Iranian nuclear program, this is far from the truth.

This analysis is lacking in several important respects.

First and foremost, none of this is news to the administration nor should it be to anyone else. Iran was permitted to keep enriching uranium under the Joint Plan of Action. This means that more enriched uranium would be present in Iran in the future than in the past. But, recognizing that, the P5+1 took the important step of requiring Iran to convert the material to a more proliferation resistant form, uranium oxide, and most of the 20 percent increase identified is in this form.

Second, the process of turning the material into oxide required the construction of a facility called the Enriched Uranium Powder Plant (EUPP). It was not completed until June 2014 and the first portion of Iran’s enriched uranium above the cap was fed into it in July 2014. But, the process is still being perfected and the IAEA has reported that Iran has not met its oxide projections yet. Work on this facility was slowed, potentially in large part, by the fact that sanctions interrupted Iran’s ability to procure the equipment needed for it (a victory of sorts for those of us who spearheaded the sanctions campaign, ironically turned into an argument for judging Iran’s lack of seriousness for implementing the JPOA). But, regardless, the uranium gas with which we have serious concerns is now in a variety of chemical forms and not available for an immediate breakout scenario. We should not lose sight of our real objective here: the point is to make UF6 unavailable for breakout. So long as the intermediate chemical forms that the uranium is transformed into through this process also achieve that objective, the U.S. national security imperative is assured.

Third, the reality is that Iran’s enriched uranium gas stocks have been in a cycle of increase and decrease around the 7,650 kilogram cap since the JPOA as a result of these technical factors. Consequently, Iran is sometimes above the cap and sometimes below it, as the graph below shows.

Richard Nephew graph

So, while it is not ideal that Iran spends some time with its material balances above the cap, the practical result is that Iran has met its JPOA obligations at the previous two extensions and, in my judgment, is likely to do so again. The physical dimensions of the plant are sufficient to accept the amount of excess UF6 available and Iran has the incentive of a comprehensive deal to do what it committed to do.

How Iran would handle up to 5 percent enriched uranium under the comprehensive deal

Turning Iran’s enriched uranium into oxide is not a permanent solution, however. Many technically-minded readers will know that turning oxide into gas takes time, but not lots of time. This JPOA requirement on Iran added time and complexity to the clock, but it is not independently a check against an Iranian breakout. Moreover, Iran’s available UF6 stocks of enriched uranium are more than enough for one weapon. Leaving aside whether anyone would be insane enough to risk military conflict for a one-weapon breakout proposition, the P5+1 wanted to address this situation for the long term by seeking a tighter cap.

As noted, the U.S. fact sheet on the parameters of a JCPOA, released on April 2, states that the amount of enriched uranium in non-fuel forms that will be permitted in the country will be capped at 300 kilograms. This is well-below what Iran could use for an immediate breakout attempt and, consequently, would put months on the clock.

Assuming a final deal is implemented, Iran would need to take further steps, either:

1.  Diluting its available enriched uranium to natural levels;

2.  Shipping the material out of the country, either for storage or for sale; or

3.  A combination of the two.[2]

Diluting enriched uranium gas is not a major technical challenge. Iran successfully demonstrated its ability to dilute 20 percent enriched uranium and the concept is similar: combine what is known as “depleted” uranium (what’s leftover when you enrich uranium) with the enriched uranium to bring it back down to natural levels. Dilution is a simple enough concept intellectually: anyone who has ever watered down orange juice to make it less thick and sweet has practiced “dilution” (note to technical people: it’s just an analogy).

Diluting uranium oxide is a different proposition. One cannot easily dilute powder. So, this material will either need to be returned to gas or, as noted, shipped out of the country.

In any event, we should pause for a moment to remember that this is a debate over an issue that the negotiators have yet to solve, not a debate over a settled deal, signed, sealed and delivered. The number having been agreed, it is a technical issue how it will be achieved but options do exist. In any event, while it is legitimate to point this out as a factor for the negotiation, it is a reach to argue that this undermines the ability of Iran to perform a function that it has yet to agree to formally and may have months to work out.

One real issue: Dealing with the 20 percent oxide stock

Ironically overlooked in the hubbub about the up to 5 percent enriched uranium stockpile has been a legitimate question about Iran’s ability to convert all of its 20 percent enriched uranium oxide into fuel. The IAEA’s report suggests that this effort may have slowed as late, which the Institute for Science and International Security (ISIS) further assessed would stress Iran’s ability to meet its target of 60 kilograms fabricated into fuel by June 30.[3]

Based on the IAEA report, I suspect the Iranians are having difficulty with the fabrication of the plates and may be trying to prevent the manufacture of flawed plates; ISIS noted the abundance of scrap and wasted material in the IAEA report as confirmation of this notion. Whatever the reason, this is an issue. But how much of one?

The IAEA report suggests that Iran may fall short by perhaps 5 kilograms from the mark set in the JPOA process, if their current rate of progress persists. Certainly, no one wants to see Iran fail to cross an important confidence-building threshold. But 5 kilograms of 20 percent enriched uranium is not a bomb’s worth. Far from it. And it remains in oxide form, not gas form, so its ready use in enrichment is reduced significantly. Assuming that this problem is of a technical nature rather than political — for it is pure speculation to suggest otherwise — there should be some understanding for the complexity of the task on the part of the Iranians.

Conclusion: Avoid turning glitches into crises

As I have previously written, there are going to be technical problems in the implementation phase of the JCPOA as well. Any sufficiently complex technical process will have delays and problems. Some are going to raise concerns and others are going to be the result of technical glitches. Some patience and reserve is needed to avoid conflating the two, turning glitches into crises.


[1] http://www.al-monitor.com/pulse/originals/2014/01/nuclear-deal-iran-economy-helps-students.html

[2] Iran’s lack of familiarity with the production of fuel rods for reactors beyond the TRR (and difficulty there) makes turning this material into fuel rods an impractical alternative solution.

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