It’s a red-letter day: David Ignatius of the Washington Post has been reading Mark Hibbs in Nucleonics Week. He [i.e., Ignatius] concludes that molybdenum impurities could prevent Iran from enriching its LEU far beyond present levels.

No further enrichment, no breakout scenario, right? Well, yes and no.

(The Mo question has been discussed at some length here, starting with a post by James Acton — see Geneva: The TRR and Enrichment Abroad, October 1, 2009.)

The problems at Iran’s Uranium Conversion Facility have been known for quite some time. Paul Kerr in Arms Control Today got a source to hint at this all the way back in 2004, as Jeff pointed out awhile ago (Got Gas? Iran Stinks at Making UF6, August 13, 2005; Iran’s UF6 Is ‘Crap’, September 28, 2005).

These problems probably have nothing to do with sabotage of equipment, as Ignatius seems to have concluded. Instead, it has to do with the withdrawal of the Chinese from the project (under U.S. pressure) ca. 1996. The Iranians had to figure out how to complete the facility themselves, and wound up substituting a key technology (see: Chinese Mixer-Settlers at UCF, October 20, 2005).

For a long time, the Iranians did not introduce their own UF6 into their centrifuges, and relied on a supply from China to test their machines. But as of early 2007, it appeared that the Iranians had resolved these problems, because they started carting UF6 from the UCF to the enrichment facility at Natanz.

The IAEA presumably knows how much molybdenum is in Iran’s UF6, but hasn’t addressed this in the Director-General’s reports; it isn’t germane. But if the Iranians can’t get the stuff as clean as they might like, the issue might have come up in the talks that have unfolded over the last few months in Vienna.

As discussed previously, the Iranians can still enrich to any level they want, but if a certain level of impurities remains in the product, that makes the process more laborious. The product would have to be hauled back to the UCF for further purification after partial enrichment, then returned for further enrichment, and so on. That really does put a kink in rapid breakout scenarios.

On the other hand, compared to the technical hurdles that the Iranians have already overcome, perfecting purification at the UCF doesn’t seem like a great challenge, and we should expect the AEOI to solve that one sooner or later, if they haven’t already.

One other point is worth considering, too. If the Iranians were to build a parallel fuel cycle, they’d probably be smart enough to collocate the parallel UCF with the parallel enrichment facility, which would make it a lot easier to do backing-and-forthing if necessary. Certainly, it will be interesting to learn what turns up at Qom during the inspections later this month, although we’re unlikely to learn before the next Board of Governors meeting, scheduled for late November.

Update: Mark Hibbs comments:

For the record—lest your readers get the false impression of my role in this debate—it should be underscored that I DID NOT conclude in my Oct. 8 article (now I’m quoting your paraphrase of David Ignatius’ piece): “moly impurities could prevent Iran from enriching LEU far beyond present levels.”

1.) We were told by a senior safeguards official in 2008 (a point which I referenced in the Oct. 8 article) that Iran had apparently solved its basic problem at UCF in removing impurities.

2.) We were also told (not only us but Paul-Anton Krueger at the Sueddeutsche Zeitung) that the arrangement which Lavrov had described as a “formula” for the P-5+1 supplying TRR fuel to Iran called on France and Areva removing impurities from Iran’s EUP. I asked Areva over a week ago to confirm or deny that and they haven’t seen fit to respond.

I think it would be fair to say that most of us following this were a little surprised to hear that the impurities issue had figured in deliberations between P-5+1 and Iran on how to handle Iran’s Natanz-enriched uranium to end up with TRR fuel.

I’ll see what I can do on Monday morning to get my Oct. 8 article posted in its entirety and let ACW readers judge for themselves what the situation is. Right now, we don’t have any official explanation for the interest of P-5+1 and/or Iran in having the French purify Iran’s EUP, for the reasons you, I, Paul, Jeffrey, James and others have gone into since 2005.

— mark hibbs · Oct 17, 10:35 AM ·