Jeffrey LewisHow Many Centrifuges?

Paul at Total Wonkerr adds some value to my post, including reminding readers of a late March story from AFP’s Michael Adler stating that a …

… diplomat said Iran had installed six cascades of 164 centrifuges each at Natanz and was test-running four of the cascades.

That would be 1,640 984 centrifuges.

I propose we follow Saeedi’s advice to “wait for the next 20 days when IAEA inspectors present their reports” to get the number, rather than inferring the worst from A-bomb’s bellicose rhetoric.

Update: My mistake, I too quickly read Adler to say that four more were under construction (rather than being test run). I suspect they have one or more cascades under construction beyond the six at the end of last month.


  1. David (History)

    I’m confused. You quote this, “diplomat said Iran had installed six cascades of 164 centrifuges each at Natanz and was test-running four of the cascades.” and then say “That would be 1,640 centrifuges.”

    But 6 times 164 is 984. So what is the other 656?

  2. Muskrat (History)

    Ummm – doesn’t that make 984? I read that sentence as meaning four of the six are being tested, not six are installed and four others are being tested.

  3. Haninah (History)

    Ooh, is this a new one? “A-Bomb” as a nickname for Mahmoud Ahmadinejad, a.k.a. MC Mahmoud, a.k.a. Mr. “Get Enriched or Die Trying”? I like it! Simplicity is the soul of wit.

  4. Haninah (History)

    Another (more substantive) point: I’m not sure where you got the 1,640 number from. It seems from Paul’s post that those four cascades being test-run were included in the six total cascades. That’s 656 being run, 984 total.

  5. fdf

    6 times 164 is 1640???

  6. Kirk Larsen (History)

    Wouldn’t that be 984 centrifuges (of which 656 are being test-run)?

  7. Jeffrey Lewis (History)

    Boy, I just totally spaced and misread Adler to say 6 plus 4 rather than 4 of 6.


  8. Robot Economist (History)

    Haninah – How about “Moodie the A-Bomb” as President Ahmadinejad’s new handle?

  9. hass (History)

    Iran says foreign enrichment offer still standsAgence France Presse 15 October 2006 0244 hrs

    TEHRAN – Iran said Saturday a year-old offer fromPresident Mahmoud Ahmadinejad for foreign countries tohandle its uranium enrichment activities still standsas a way to break the deadlock over its nuclearprogramme.

    Foreign ministry spokesman Mohammad Ali Hosseini alsosaid a suggestion made by Iran earlier this month fora French led-consortium to enrich uranium for Iran onIranian soil remained “appropriate”.

    …”Mr Ahmadinejad in his speech last year to the UNGeneral Assembly proposed that other countriesparticipate in the uranium enrichment and thisproposal still stands,” Hosseini said, according tothe website of state broadcaster IRIB.

    Ahmadinejad had proposed in that speech to “engage inserious partnership with private and public sectors ofother countries in the implementation of the uraniumenrichment programme in Iran.”

    His idea was revived earlier this month when a topIranian nuclear official said France should form aconsortium that would manufacture uranium on Iraniansoil and thus break the deadlock.

  10. Brad Arnold (History)

    Frankly, I am surprised that anyone would care how many centrifuges Iran is using-they are clearly shooting for industrial enrichment, and will brook no opposition.

    Instead, it seems more rational to be concern about Bush ordering a preventative attack on Iran. Iran will predictably escalate, resulting in a war of unknown duration and intensity.

    In other words, the imminent grave danger is Washington overreacting, not Iran enriching.

  11. Otfried (History)

    IAEA has informed Iran that it’s current montoring equipment can cope with 500 zentrifuges, i.e. with 3 cascades of 164, but not with 4 (656).If Iran runs more than 3 cascades, there’d be a new area of serious conflict with the IAEA unless the monitoring issue, which currently is under discussion, is resolved.The latest IAEA report cites two cascades already testrun and two more short of completion.If the additional two are ready for testing now, the 500 limit would be crossed.If I remember right, Iran defined 2 cascades as “pilot stage”. That stage would be left, too.In result, it’s likely that two more (i.e 4 in total) cascades are ready to (test)run.That’s still short of 6 (984) already completed for testing, but in line with the public statements that are available.


  12. Haninah (History)

    Robot – perhaps “Mahmoudie and the Blow(up)fish”? Ok, that’s a stretch already…

  13. Otfried (History)

    According to a Reuters report ( IAEA Deputy Director Oli Heinonen found 8 cascades of 164 centrifuges each, when recently visiting Natanz.If these figures are correct, Iran has speeded up the installation of additional centrifuges beyond the assumptions of both, Al Baradei and our earlier discussions here.This development highlights the importance of reliable estimates on how many centrifuges Iran can assemble.

  14. Jeffrey Lewis (History)


    Estimates here are actually in agreement with Heninonen’s claim.

    In this post, I expressed my sense that “I suspect they have one or more cascades under construction beyond the six at the end of last month.”

    Six plus two is, well, eight.

    I was willing to believe up to ten cascades—which is pretty much the schedule that most of us expected.