Andreas PersboEnriching Salehi’s Statement

Iran’s enrichment effort continues to move forward as their scientists and technicians continue their relentless pursuit of ever higher enrichment levels, and ever more effective centrifuges. At least that’s the official story, eagerly broadcast by Iranian officials.

Few have probably missed the 23 June claim by Mr. Ali Akbar Salehi, the head of the Atomic Energy Organization of Iran, that Iran has produced 17 kilograms of 19.75 per cent enriched uranium hexafluoride gas. He also said that his outfit can produce as much as five kilograms a month. ISIS has pointed out that Mr. Salehi’s statement does not square neatly with the IAEA’s latest report on Iran.

The report suggests that the product flow rate between 9 February and 7 April has been precisely 100 grams a day (according to the IAEA logs, the Iranians withdrew 5.7 kilograms after 57 days). If Mr. Salehi’s production claim is true, the flow rate for the period 9 February to 23 June has in fact been about 127 grams a day.

If you think that most of the 11.3 remaining kilograms of uranium hexafluoride gas was produced after 7 April, the product flow rate of the facility jumped from 100 to about 147 g/day. That is [still] a remarkable increase in productivity.

Mr. Salehi does say the cascade can produce that much. He’s claiming that Natanz can gear up to around 164.5 grams a day. This, to me, sounds optimistic.

If the P-1 machines were running at their theoretical limits, one 164 machine cascade should not be able to achieve a higher product flow rate than about 112 g/day. This is assuming 2.2 SWU/machine, an average feed enrichment of 3.5 wt %, and a tails enrichment of 0.2 wt %. Increasing the tails to, say, 0.5 wt % could pump up the flow rate to about 155 g/day, which still falls short of Mr. Salehi’s statement, and well short of 200 grams a day.

Indeed, on a single cascade, the tails would need to be set to 0.6 wt %, all other variables being equal, to achieve the stated capacity. In other words, the cascade would have close to natural uranium in its tails, flowing out at 934 g/day. I leave to others to judge whether this is an economical way to run an enrichment plant.

This leaves the alternative that Iran has put both cascades into action. Having two cascades of P-1 centrifuges, again at peak performance, will increase the flow rate to 224 g/day, assuming a 0.2 wt % tails setting. Mr. Salehi’s estimate of 164.5 g/day makes sense in that context. However, the latest Agency report reveal that as of 24 May, the second cascade was not put into operation. Even if it were put on-stream the following day, it is unlikely that the two interconnected cascades can have brought the balance up to 17 kilograms.

It should be said in closing that diversion risks are tiny when material balances are this small, provided the IAEA is allowed to apply safeguards as it considers right. Rumblings from senior Iranian officials that Iran may in fact reduce its cooperation with the IAEA are therefore unfortunate. How Iran intends to draw down on cooperation is also fundamentally unclear, since they presently seem to cooperating at the bare minimum.

Update: A friend of the wonk has pointed out that increasing the feed rate would result in reduced enrichment. So if Iran would have bumped up the feed rate, it would in fact dilute the product quite a bit. That’s something to ponder indeed.

Update 2: Thank you Ataune for spotting a calculation error. 11.3 kg / 77 days is 146.8 grams per day. The post has been revised accordingly.

Update 3: Thanks for all comments, both on and off-line. The general thrust is that although SWU calculations – on which this post is based – can be useful, a cascade calculation will yield better results. In fact, the tails are most likely LEU and not DU as posted here. When I get back from Wilton Park, I’ll revise the post to in light of all comments. This is a truly remarkable readership – none mentioned none forgotten.


  1. A (History)

    I think Iran will suspend its membership in NPT soon, It seems very rational specially after new rounds of sanctions. Why Iran should remain in NPT when there is no benefit of this membership?

  2. Ataune (History)

    There are 3 layers here that need to be separated to have a correct understanding of the brinksmanship between Iran and the US on the nuclear issue:

    At the technical/legal level, Salehi, part of the executive branch, is a technocrat with diplomatic background running Iranian Nuclear Agency in a professional manner and, judged by Iranian internal politics, in a fairly multi-partisan way. Salehi’s interview with ISNA, to which you refer, has an overall positive tone. He mentions several times the Vienna group’s letter to the IAEA (in response to the Tehran’s IBT – Iran/Brazil/Turkey – agreement and the subsequent letter sent to the IAEA by Iran) revealing some of the 9 points in Vienna group letter and proclaiming candidly his optimism in reaching a modus vivendi with the Vienna group based on Tehran’s agreement. He also mentions that Tehran will be sending its response to the letter very soon, answering all the questions in it point by point.

    At the Iranian internal political level (somehow mirroring the American side), it is Larijani, head of the legislative branch, a potential candidate for the presidency in 3 years and an outspoken critic of some of Ahmadinejad’s policies, which is driving the push to introduce legislation to reduce Iran’s cooperation with the IAEA. You need to know that the executive branch in Iran has to abide by the directives of the Majlis on this kind of issues and can not overrule it. I am pretty sure that Larijani’s team of advisers are capable of finding somewhere in Iran’s safeguard agreement some clause that they can either downgrade or even scrap. The outcome of Iran “drawing down” its cooperation with the Agency will clearly depend on how the internal fight feud between the legislative and the executive plays out.

    At the level of power play between Iran and the West and all the theatrics associated with it, Ahmadinejad said 2 days ago that Iran will announce on Monday the pre-conditions for the talks that Catherine Ashton, Europe’s Foreign policy head representing the 5+1, has requested in a letter to Iran. Given the fact that Ahmadinejad is rather eager to produce an agreement I don’t expect these pre-conditions to be a real obstacle to the talks.

    By the way, I don’t have any insight into Iran’s current technical abilities in the enrichment field, but from Apr 7 to June 23 I counted 77 days and if you divide 11,300 grams by this number it roughly makes 146 grams per day and not 198/day as you mention.

  3. Andreas Persbo

    Ataune. Thanks. Well spotted.

  4. b (History)

    “relentless pursuit of ever higher enrichment levels”

    Why was that quite opinionated snark necessary?

    There is no “relentless pursued” but deliberate technical steps taking in pursuit of clearly announced rational politics.

    There are also no “ever higher enrichment levels”. Iran enriches to 3.5% for normal reactors and to 19.75% for the TRR.

    How is that “ever higher”?

    If the “west” does not like the 19.75% enrichment, just deliver the needed fuel for the TRR and Iran will stop to enrich to that level.

  5. hass (History)

    A – Iran will not suspend its NPT membership because 1- the US has been trying to force Iran out of the NPT for a long time (Bolton was hoping for that reaction) in order to paint IRan as an “outlaw” and 2- the IAEA, despite the hype and misrepresentation in the media, continues to cerfify that Iran’s nuclear program is in full compliance with the NPT according to its safeguards. In fact Iran has the sympathies of most if not all the Developing nations, most significantly Turkey and Brazil who, in the very first article of their agreement with Iran, explicitly stated that enrichment is a sovereign right, contra the US who claims that it is merely a “loophole” to be closed.

  6. Sébastien Philippe (History)

    Having a look pages 2 and 3 of the last IAEA report (GOV/2010/28), you can read that the two 164-IR1 cascades interconnection is aimed at reducing the tails level to natural uranium: “by applying this modification the enrichment of Tails [is] expected to be reduced from ~2% to ~0.7% U-235”.

    This is interesting if you have also a look on Alexander Glaser’s S&GS paper (GLASER, ALEXANDER ‘Characteristics of the Gas Centrifuge for Uranium Enrichment and
    Their Relevance for Nuclear Weapon Proliferation’, Science & Global Security, 16: 1, 1 — 25).

    The Iranian cascade will now show great similarity with the cascade arrangement of the Lybian enrichment project presented page 19. That include: feed, product and tail levels plus the number of centrifuges used to produce 3.5% U-235 UF6.

    Maybe just a coincidence.

  7. shaheen

    Am I the only one on this blog who believes that opinions not based on facts are useless here?
    Hass, pls. demonstrate your assertions:
    1. “the US has been trying to force Iran out of the NPT for a long time (Bolton was hoping for that reaction)”. Unsubstantiated.
    2. “the IAEA (..) continues to cerfify that Iran’s nuclear program is in full compliance with the NPT according to its safeguards”. In which report did the IAEA say that Iran was “in full compliance with the NPT”?
    3. “the US (..) claims that it is merely a “loophole” to be closed”. When did the US say that “enrichment is a loophole”?
    This is either sloppy analysis (to be very charitable) or disinformation.

  8. Barmak (History)

    “In fact Iran has the sympathies of most if not all the Developing nations”

    Those countries include Gabon, Uganda, Nigeria who supported Iran at the non-aligned movement with unanimous vote, then 24 hours later they voted against Iran at UNSC. They are useless. Iran doesn’t have any sympathy from any country which matters. Brazil will probably turn against Iran too, as did Argentina. I was surprised even China took side against Iran, I thought this time China had an excuse to stay on sideline. Arabs are against Iran as well. Turkey is a different story but Turkey can’t risk getting itself isolated along with Iran. Iran doesn’t have any choice, either Iran has to end its nuclear program or withdraw from NPT, which means making nukes, war, or some sort of cold war. That’s what John Bolton meant. He was basically raising the stakes, to give Iran a choice: either back down or get out of NPT. US obviously prefers Iran takes the former option, whereas the likes of Bolton were hoping Iran would take the latter option so US could get another war going.

  9. Andrew


    On point 3, John Bolton has said Bush proposed to the NSG a solution to close the ‘loophole’ that allows states to pursue alleged production of fissile material for nuclear weapons under the cover of peaceful nuclear development. Former US Secretary of State Rice also discussed U.S. efforts to close the ‘reprocessing and enrichment loophole’. The NNSA also said that former U.S. President George W. Bush called for closing the Nuclear Non-Proliferation Treaty ‘loophole’ by restricting the spread of sensitive enrichment and reprocessing technologies.

    On point 2, the IAEA has never passed judgment on whether Iran is or isn’t in compliance with the NPT; however, the IAEA has confirmed that there is no diversion of safeguarded material in Iran. It remains unable to draw conclusions about undeclared material because Iran, like many other IAEA members, has not fully implemented an Additional Protocol (Iran stopped voluntarily implementing an AP after the US ignored Iranian negotiation overtures)

    On point 1, the U.S. has arguably ignored multiple chances to negotiate limits to the Iranian program (when Iran has suspended enrichment and implemented an AP, when Iran has offered to send uranium out of the country, etc) and instead pursued sanctions, and previously threats of force, as a primary route over negotiations, which may or may not be the best route. It comes down to whether you believe sanctions will end Iran’s program.

  10. kme

    A: One long-run, continuing benefit to Iran of the NPT that should not be overlooked is that the NPT restrains several of Iran’s close competitors from operating a nuclear weapons program (most pertitently: Turkey, Saudi Arabia and Egypt).

    Although several of Iran’s other near-neighbours are not restrained by the NPT (Russia, Israel, Pakistan and India), the continuing viability of the NPT still appears to be in Iran’s interest.

  11. bradley laing (History)

    -AP – Sun Jun 27, 10:44 am ET

    WASHINGTON – CIA Director Leon Panetta says Iran probably has enough low-enriched uranium for two nuclear weapons, but that it likely would take two years to build the bombs

  12. barmak (History)

    “NPT restrains several of Iran’s close competitors from operating a nuclear weapons program (most pertitently: Turkey, Saudi Arabia and Egypt)”

    New UN sanctions do not allow Iran to purchase conventional arms. Meanwhile Iran’s neighbors have armed themselves to the teeth. Not to mention nuclear armed Israel. So in that respect it is in Iran’s interest to withdraw from NPT and make nukes as primary line of defense. The only reason Iran stays in NPT is fear of war with US, or some sort of endless escalation with US.

    Also there was that thing in 1980s when Saddam Hussein was using chemical weapons against Iran, in addition to Saddam’s nuclear weapons program, but there were no UN sanctions against Iraq at that time. This whole international law is not really what you might call “rules”, but more of a guideline, and it’s meant for the interests of major-powers, not smaller countries.

  13. Ataune (History)

    The pre-conditions for the talks requested by 5+1 have just been announced by the Iranian President and here there are:

    . 5+1 needs to declare their position regarding Israel’s Nuclear Weapons
    . They need to declare that they abide by NPT as an international treaty
    . They need to clarify if their ultimate goal from the negotiation is friendship or enmity.

    There are 2 additional caveats added. The negotiation will start in one month and the group can be expanded to include others (most likely Turkey and Brazil)

  14. shaheen

    Andrew, thanks for the effort.
    3. I had indeed missed the US “loophole” rhetoric. But the fact the the NPT is an imperfect treaty had not escaped me…
    2. Agree – that was my point. Of course the IAEA has not said (and does not have the authority to say) that Iran abides by (or has violated) the NPT.
    1. Pure opinion. (I strongly disagree with your descripion; in fact, Iran does not “offer” anything when it’s not under pressure; but again we’re not here to discuss opinions, are we?).
    Are sanctions enough for Iran to change course? Not on their own.

  15. Nick (History)

    Unfortunately, current USG’s ultimate goal is enrichment halt; a continuation of failed Bush policy. I don’t see why a meeting with P5+1 will change anything on that topic. Obama doesn’t have the political will to accept IRI’s enrichment, because of the sever impact that it may have on 2010 and 2012 elections.

    Even if the outcome of this proposed meeting in August is a mickey-mouse limited enrichment with the obsolete IR1s and one or two cascades and a halt to R&D for advancement of this technology in Iran, as proposed by Mathew Bunn, it will have zero traction with IRI. It will be doomed before it starts.

    If Obama wants to make progress with Iran, he must replace Gary Samore as the point man in dealing with Iran’s nuclear issue; but I find that very unlikely, so there will be little progress on the diplomatic front. In my opinion, Obama would rather isolate and encircle Iran with naval and other assets than jeopardize upcoming elections by accepting IRI’s nascent enrichment capability.

  16. archjr (History)

    Let’s enrich this thread by acknowledging the IAEA Board Resolution of November 2005, where the Board found “that Iran’s many failures and breaches of its obligations to comply with its NPT Safeguards
    Agreement, as detailed in GOV/2003/75, constitute non compliance in the context of Article XII.C of
    the Agency’s Statute;”.

    Until Iran is found to be in compliance with its safeguards agreement, it remains non-compliant. This fact may be hard for some to remember, but there it is.

  17. Andrew

    Arch, you are of course referring to compliance with the safeguards agreement, not the NPT, and of course it would also be noted that the Resolution was passed in a rare non-consensus vote which was highly political (as Egypt and South Korea have also had safeguards violations reported, but then not had a political decision made).

    Let’s also enrich this thread by remembering the right to enrichment which all signatories to the NPT have. Allow us to also not forget that many industrialized nations indeed exercise their right to enrichment on a quite regular basis, and that many nations (35-40 depending on the estimate) could be described as virtual nuclear states.

  18. archjr (History)

    Andrew, it’s clear from the resolution(s) that Iran’s compliance with the NPT is not called into legal question, and of course there is nothing in the NPT that prevents indigenous enrichment.

    The vote, however, was pretty clear, despite the unusual fact of having a vote at all: it was something like 27-5 with 3 abstentions. This is a far cry from the first, Bolton-sponsored draft resolution, where Amb. Brill had the pleasure of informing an enraged Mr. Bolton that his draft, if put to a vote, would fail 34-1. Member States have generally lost patience with Iran’s negotiating tactics, and the disrespect Iran has shown for the inspectorate.

    Finally, Egypt and South Korea made good on their safeguards obligations, and avoided referral to the Security Council. Big difference there.

  19. shaheen

    Andrew – no, Germany, Japan, etc. are not in the same league as Iran and are thus not “virtual nuclar states”.
    What distinguishes Iran inter alia is secrecy, conduct of nuclear activities under the aegis of the ministry of defense, refusal to implement the AP, tests of baby-bottle design of a third stage of a missile, etc., etc., and most importantly weaponization activities. If you have publicly available evidence that Germany or Japan (or a few others) have conducted weaponization activities, pls. provide it. It would make this debate more interesting.
    Ah, and, again, there is no “right to enrichment” per se in the NPT. The framers refused to include an explicit right to fuel cycle activities.

  20. Ataune (History)


    The truth or fallacy of the accusations made against Iran’s civil nuclear activities, is a matter to be yet proven by the accusers, but regarding your sentence “there is no ‘right to enrichment’ per se in the NPT” a clarification is necessary:

    Any sovereign state has ‘per se’ the right to uranium enrichment at any level deemed necessary and the full or partial development of the fuel cycle in its territory. Not being a NPT member would also give this state the sovereign right to develop nuclear weapons. By becoming UN member any state is basically accepting the sovereignity of other States over their political/geographical boundaries and their right to defend that. By becoming a member of the NPT The Have-Nots, by ratifying the NPT, have agreed to be stripped of their right to develop nuclear weapon, and this ‘til they are party to the treaty. Other states, them being NWS or NNWS, have accepted the sovereign right of all the members to the full nuclear fuel cycle. Therefore, no NPT party can be stripped of its inaliebale sovereign right to full fuel cycle based on the NPT. The only way to have that right taken away is for the state in question to sign an internationally abiding treaty, under no coercion, relinquishing its sovereign right. This latter explain much of what is hapening now in the international political arena with the artificially hyped “Iran nuclear issue”.

  21. Andrew


    The World Nuclear Association has estimated there are 434 operable nuclear power plants, 53 under construction, 134 planned, and 300 more proposed nuclear power plants in at least 32 countries. A partial listing of countries which have or have had some type of enrichment include Australia (laser enrichment), Argentina, Brazil, China, France, Germany, India, potentially Israel, Iran, Japan, the Netherlands, North Korea, Pakistan, Russia, South Africa, South Korea (though microscopic), the United Kingdom, and the United States. Several more states may get into the uranium-enrichment or plutonium reprocessing business, allowing them to become virtual nuclear-weapon states. Any industrialized nation today has the technical capability to develop nuclear weapons within several years if the decision to do so were made, and larger industrial nations (Japan and Germany for example, probably using plutonium) could (within several years of deciding to do so) build arsenals rivaling those of the U.S. and Russia.

    The former director general of the IAEA estimated that in addition to the nine armed nuclear powers, 20-30 countries are “hedging their bets” by possessing the
    knowledge and technologies that would allow them to rapidly develop nuclear weapons for possible future contingencies. There are perhaps 50 countries that could build nuclear weapons if its leadership so desired; some could do so quickly and for others it could take a decade or more.

    For a particular case study, Egypt has an essentially single party political system marked by violence and the imprisoning of political opponents. Egyptian human rights are severely wanting, with problems in freedom of the press, freedom of religion, torture, etc.
    Egypt has refused to sign treaties prohibiting biological and chemical weapons, and has previously used biological and chemical weapons of mass destruction. Egypt at least previously had a bomb program, has had traces of uranium suitable for a weapons found in their country, has had “repeated failures .. to report nuclear material and facilities to the Agency (IAEA) in a timely manner”, has refused to implement the IAEA Additional Protocol, has access to bomb quantities of fissile material, and has recently had open debate about the pragmatism of developing nuclear weapons.

  22. Ronbo

    many thanks for the Weekly Ahram link it was without a doubt one of the funniest things I`ve read all week,egypts nuclear program sounds as much of a failure as its long range missile programs and yet both are the oldest in the region

  23. shaheen

    Andrew, not to overdo it, but you’re obuscating the issue.
    1) My point was and remains that putting Iran in the same category as other countries that have an enrichment program is unsupported by facts (being defined here as IAEA reports – at least not political quotes by a former DG).
    2) 434 reactors do not make for 434 convenient sources of fissile material – most power reactors are LWR.
    3) The Egypt/Iran comparison is particularly useful in this regard; Egypt’s violations of its SA can hardly be compared in scope and nature to Iran’s violations (again, per IAEA reports only). And to claim that Egypt has currently “access to bomb quantities of fissile material” is extraordinarily misleading. The fact is that Egypt has a safeguarded research reactor that could theoritically produce some 5-6 kilos of badly suited Pu a year, and only if diverted. (The relevant comparison here would not be Natanz but Arak: a perfectly suited reactor, and twice the power). No weaponization studies (nor missile adaptation studies) are known to have been conducted in Egypt.

  24. Andrew

    Egypt has a Soviet-supplied research reactor, a light water research reactor, a fuel manufacturing plant, a hot cell complex, and a waste management facility. Egypt has also announced plans for the construction of up to 10 nuclear plants. Egypt has previously had the IAEA report “unreported nuclear material, activities and facilities in Egypt”, and that Egypt “has conducted experiments, which had not previously been reported to the Agency, involving the irradiation of small amounts of uranium and thorium and their subsequent dissolution”. Egypt has also refused to implement the Additional Protocol, leaving the IAEA unable to verify the current status of undeclared material and activities within Egypt. Further, the IAEA even found traces of highly enriched uranium in Egypt, which is material which could be used in a nuclear weapon. This doesn’t explore South Korea at all.

    Further, what leads us to believe that there will never be any change in intention in any ‘good’ virtual nuclear weapon state? Didn’t Germany have a dictator just some 60 years ago? Will there never be a change in intent in any of these countries?

  25. Andrew

    The argument here is less about how bad Egypt is, and more about how reactionary and selective one could perceive the discussion to be.

    The point stands that there are nine countries with 22,000 actual nuclear weapons, and that there are already many virtual nuclear states which could have nuclear weapons within several years of a decision to do so. The IAEA has 151 Member States, but only has Additional Protocols in force for 101 of these member states, leaving it unable to draw conclusions about unsafeguarded material in about a third of its Member States.

    Will there never be any worries about the existing nuclear weapons? What about nuclear weapons stationed in Belgium, Germany, Italy, the Netherlands, and Turkey? What about uranium enrichment in Argentina, Brazil, China, France, Germany, India, Japan, the Netherlands, Pakistan, Russia, the United Kingdom, or the United States? Aren’t there multiple routes to the bomb? What about the virtual nuclear capabilities of the other states, which may not always have the same intentions and all already have a low nuclear latency?

    So maybe we should also be worried about leaks and insecurity in an unstable Pakistan that already has nuclear weapons, unsecure weapons being shared by NATO, anticipating problems in current and upcoming virtual nuclear weapon states, among other myriad problems.