How quickly can Iran get the bomb?

Obviously a lot of smart and well-informed people have been thinking about this. Many, like Juan Cole, think that the Iranians are nowhere close to a bomb; ThinkProgress is slightly less sanguine. They are taking the trouble to make this argument because the US is claiming that it would only take 16 days for Iran to make a bomb. There are all sorts of reasons to disbelieve this particular claim: a history of crying wolf, an apparent misunderstanding of the concept of significant figures… Still, is it more like ten days, or ten years?

Steinn Sigurðsson looks at the problem as a physicist, and isn’t optimistic.

I don’t know Iran; I don’t have access to any classified information on nuclear weapons.
I do know something about physics…

First of all, Iran is clearly been working on putting together a full nuclear cycle for about 20 years

That means they want to be able to do it all in-house: mining, enrichment, burning, plutonium extraction, power generation and bomb production.

It is clear that they did the science in the early-to-mid-90s, they tested centrifuges, built small high neutron flux reactors and got small amounts of plutonium extracted.

So, they learned Pu chemistry, what isotopes you get with different burns, and maybe some metallurgy.

They then set up centrifuge halls and played with an AVLIS (laser isotope separator).

They also ordered a 1GW reactor from the russians, and refined uranium oxide (aka “yellowcake”) into both uranium tetrafluoride, uranium hexafluoride and uranium metal.
Supposedly several tons of uranium oxide were processed.

Now: there are two ways to make bombs, at the basic level.
Get highly refined uranium-235 metal; or, fairly pure plutonium-239. In kilogram quantities.
U-235 bombs are simple and need not be tested. “A grad student could make one of those”.
Pu-239 bombs are notoriously fickle and are said to need testing (although maybe not so much any more…)

Read the whole thing.

Hofstadter’s Law says “It always takes longer than you think, even when taking into account Hofstadter’s Law.” For nuclear weapons, unfortunately, the word “longer” should be replaced by “shorter.” Historically, we always underestimate the proximity of other nations to full nuclear capability (unless we’re trying to cook up reasons to invade them). I don’t know what to do about it, but there’s every reason to believe that, left to its own devices, Iran will have some sort of bomb sooner rather than later.

66 Comments

66 thoughts on “How quickly can Iran get the bomb?”

  1. I think one has to assume that a lot of the engineering one typically needs has been supplied to them via Pakistani scientists and engineers. If not the Russians. (Not a lot of pay for physics in Russia) I’m sure both Pakistan and the US is trying to prevent this. But there’s only so much one can do.

    So it’s all about the processing. And a small bomb is still a significant weapon. Especially when the President of Iran apparently really likes the idea of bringing back the 12th Mullah in an Islamic version of the apocalypse. I only know about him what I’ve read in Time, Newsweek and so forth. But it’s pretty scary. I’ve met some fundamentalist Christians who get excited by the notion of the apocalypse. It’s a mindset I just can’t fathom. But from that mindset, I’m tremendously scared that its in their best interest to use such a weapon (or at least supply those who would). Especially if Bush or Israel launches, as expected, some kind of attack the next few months.

  2. I seem to remember reading somewhere that simply dropping a good-sized hunk of enriched U onto another from a fairly modest height (perhaps a couple storeys) could generate an explosive critical mass of multi-kiloton power. I don’t know if it’s really that easy, but it’s clear getting the weapons-grade fissionable material is the real hurdle, and crude bomb construction (an old cannon barrel and some gunpowder might do in a pinch) is trivial by comparison.

    I figure even the great majority of Iran’s leadership isn’t crazy enough to allow weapons-grade U or Pu to get loose. Thing is, all it would take is a few improperly supervised nutcases, and suddenly an extraordinarily lethal mass of explosive material is within reach of Islamist extremists. As Iran can get all its U domestically, it’s not clear to me how one could be confident that could safely be avoided if Iran chose to flout all international oversight.

    I hate to side with the hawks, but this is a legitimately troubling scenerio.

  3. The problem is that an attack will probably make things worse, not better. i.e. it will give support to the hawks in Iran and potentially radicalize even more people. I’m not sure there is a solution at all. And I have no faith in Bush to do the right thing. (And I say that as a Republican)

  4. the one intelligently designed

    “Iran will have some sort of bomb sooner rather than later.”
    So?

  5. It seems if there ever was a time when a military strike made sense, it’s long past. Iran’s nuclear infrastructure is now so dispersed and hardened, making a real dent in their capabilities is tantamount to launching a full-scale air war, and would probably lead to the release of huge amounts of radioisotopes into the atomosphere.

    I guess my point is I don’t think this is Iraq redux. There was no nuke-u-lar threat from Iraq. Iran’s a different story. While attacking Iran is (if we wish to be sane) off the table, it’s not absurd to pressure them to bend over backwards to assure the rest of the world their nuclear program is peaceful, and that their fissle resources are secure, and not weapons grade. The place is a theocratic sponsor of terrorist organizations. There’s no way around it: Militant mullahs with the Bomb can’t be shrugged off.

  6. I guess its really scary to think, but I wonder, what would a nuclear power like the US or anyone else do if they where hit by a terrorist nuke. I tend to not think about these things as visions of the end of the world can be amazingly depressing.

  7. I think if there were a US nuclear strike there would be tremendous pressure on the President to pre-emptively attack North Korea and Iran. Whether they would would depend upon who the President is.

  8. This is going to require finesse. First of all we need complete policy alignment with the U. S. European nations, Russia, Japan, and other democratic countries around the world. One voice. Secondly we need to acknowledge the right of the Iranians to have nuclear power as fundamental. Then we need to work cooperatively to ensure that they ensure the security of the material. Finally we need to begin an open (and honest) dialogue with the Islamic world and realize that they have as much right to their belief structure as we do and that we cannot impose Western values on them. Perhaps this is naive but I think the alternatives are all the more unpleasant.

    Elliot

  9. I’m not worried by Iran having nuclear technology.

    I’m worried by the americans (the only ones who ever used a bomb) that could have an excuse to attack them.

  10. Iran sent a lot of people into engineering and physics in the mid-late 70s and early 80s. I know some, including some who went back to Iran.
    They were very good.
    They have enough money to buy any equipment on the open or gray markets.
    If the Iranian government makes it a priority and resists the impulse to micromanage then putting together a fission bomb is not an engineering issue. It is just not that hard to make something that will go boom on kiloton scale.
    IF they get fissile material.

    Soon as Bushehr-1 core is loaded they can do short burn runs, and start extracting Pu-239 in multi-kg amounts on 3-6 month time scale. Enough for 3-10 bombs per burn cycle, or the apocryphal “30 per year”.
    They’d have to boot the IAEA and either boot the Russians or have their passive acquiesence, since for electricity production you burn the HEU longer and the Pu goes to Pu240/241, bad for bombs. Anyone there would notice that rods were being pulled too soon for reprocessing if the run is for power.

    Direct enrichment of uranium ore is not really that good for bomb production, except maybe to rush 1-2 small bombs off the front end of the run; you enrich uranium to get the Pu cycle going. Then you make lots of bombs.

    Someone in DC is probably very worried about whether they could have built a 10+MW heavy water reactor running on unenriched uranium, and hidden it completely somewhere. It is conceivable. They could pull out enough Pu-239 for a bomb maybe every six months to a year depending on how clever they are in managing the neutron flux and reprocessing. If they did that sometime between 1997 and 2003 they could have extracted enough Pu239 for a few bombs. But they won’t be absolutely sure they’d work, and they won’t want to reveal their hand by testing until it suits them.

  11. I would say the “Hoftstader law” you quote is spot on. If they are determined enough they will do it. The Soviet Union was never far behind the US and set off their first A-bomb (“Joe 1”) in the late 40s, much to the shock of the US. Truman was shocked and astonished that “those asiatics”, the Russians, were actually capable of constructing something as complex as an A-bomb. One should not underestimate Iran either. To stay ahead Truman then initiated a race for a superbomb or hydrogen bomb, a weapon of virtually unlimited power. Again, just a few years, after the Castle Bravo hydrogen bomb tests in the Pacific, the Soviets had the hydrogen bomb too. Spying may have been involved (via Klaus Fuchs). However, Sakharov in his memoirs says they worked it out for themselves and I would bet Iran can too if they have some smart people working on it.

  12. Dr. Sigurdsson,

    Thanks so much for your highly topical discussion and for sharing your personal experiences related to Iranian nuclear capabilities. I have a question, if you don’t mind.

    What makes Pu bombs so “fickle” and challenging to build reliably? I guess I’m kind of pinning some of my hopes on that statement…

  13. I dont think anyone really expects Iran never to have the bomb. Its always been more a question of when.

    Otoh, Israels bombing in the 80s did set them back awhile, and arguably this was a good thing (Khomeini wasn’t exactly the most rational player on the block). I’m not so sure if their current president is as bad (he seems to try to make himself out like that), but regardless we might have to intervene just for the delay factor (again) hoping that when next this problem arises a more favorable and rational government is in place. Wishful thinking maybe, but I haven’t heard a better alternative yet outside of diplomatic means (which are quickly exhausting)

    I’m more or less in favor of going down this route, b/c frankly as it stands, Iran is still a nation that funds terrorism and im not exactly pro regional arms races for security purposes, especially in this climate.

  14. It would have been interesting to see what would have come of Iran if anyone other than Jimmy Carter was President when the Shah was overthrown.

  15. Personally it is hard for me to have such discussion without asking the obvious question of who wants me to have this discussion and for what purpose…now when I really want to be scared I recall previous instances when the usual murmur of fear-mongering was suddnely dramatically increased in volume, usually this does not end well…

  16. shouldn’t the world be wary of fascist leaders that threaten to wipe out millions of Jews? It usually ends up bad, not just for the Jews, but for all of us.

  17. Otoh, Israels bombing in the 80s did set them back awhile, and arguably this was a good thing (Khomeini wasn’t exactly the most rational player on the block).

    Umh … That was Iraq, not Iran, whose Osiraq reactor facility was bombed by the Israelis in 1981.

    Not confusing Iraq and Iran is probably a good start in figuring out how to deal with the current situation.

  18. 1- If our crazy president (Ahmadi-Nejhad) makes some dangerous fault, is your crazy president (Bush) in the position to punish him? If you think so, what’s your reason? Who gave him that right? If you don’t, then why you all (not just Sean) take this as a valid statement in your arguments?
    2- For nearly 4 years, this has been (and continues to be) an advertised public law in Iran that the government neither wants, nor has the right to make any nuclear weapon. As an Iranian, I’ve never met someone here (in Iran) who thinks that we should have nuclear weapons. Now if the Iranian government says or performs something toward nuclear weapons, would the nation protect it? Noway. You can’t even think of what may happen then. People will not bear it and it would be an endpoint to the life of this regime. Making such weapons is manifestly against our religion and culture.
    3- The most simple question: If nuclear weapon is really bad, why countries like US, Russia, India and Israel can have it and there’s no problem, but Iran should not even get close to it? (especially regarding the fact that our neighbor countries have it) I say again that we don’t want it, but even if we did, this would be some “reason” for it.
    4- All Iran’s nuclear facilities and laboratories are under tight control of IAEA. Is there a chance of enriching uranium up to more than 90 percent instead of just 3.5 to 5 percent before their cameras? You say we may do it underground? Then what’s the use of all military satellites that your country has?
    No. We Iranians don’t need it.

  19. Accuse me of being especially naive on the motivations behind Iran’s plan for nuclear buildup. As a momentary means to counter these universal thoughts on global destruction, I will pause and put forth a trivial antidote to offset this bit of global angst among us all. If the Iranian nuclear program is merely intended for purely civil/peaceful purposes, then at least Iran is playing an active role in producing carbon-free energy, in turn, putting a slight damper upon the world’s carbon dioxide emissions. Paraphrasing Nathan Lewis in a webcast talk at Caltech (5/25/2005): we ought to credit Iran for doing its part to curb its fossil fuel consumption, in turn, to mitigate global climate change. Is this as actual glimpse of optimism in a sea of pessimism? Probably not. If the human-produced nukes of war do not wipe out complex life on Earth, the Venusian Inferno/Snowball Earth resulting from human-induced climate change will.

  20. I really think that the way the world works has to change. In order to resolve something diplomatically, the parties need to have diplomatic relations with each other.

  21. Torbjörn Larsson

    I’ll agree with Mostafa on the point of nuclear politics bigotry. OTOH we want to restrict the number of hasardous players if possible. I’m not sure playing the hasardous game itself is the best solution.

    Cynthia,
    You seem unduly pessimistic. IIRC, the Earth has survived massively larger amounts of greenhouse gases than the current antropomorphic projections without going hothouse. The known catastrophe is that we now live in what I think is believed to be the fastest dieout ever, a large part of which is caused by climate effects.

    Every species is unique, so I mourn it on this principle as much as loosing any individual person. Hopefully it will get back to low enough species turnaround when global population stabilises so this situation stabilises too. Otherwise we will continue lower potential ecological economical outputs and safety margins.

  22. Torbjorn, you make a legitimate point. However, there is one subtle difference between Present Earth and Past Earth. Unlike Present Earth, Past Earth had an overall greater capacity for ecological recovery. This past youthful resilience enabled Earth to successfully recuperate from past assaults of extreme hot and extreme cold. More to the point, when Earth had more youthful vigor, the planet was better able to survive as a complex-life-sustaining planet by thriving on the great elasticity of its “geologically-active” status. Therefore, one must have slight respect for Iran’s efforts to produce carbon-free energy, in turn, to mitigate global climate change.

  23. The real danger is not an Iranian atomic bomb, because they won’t be able to use it. The US and Israel are afraid that Iran could use nukes against Israel. But in that hypothetical case, despite an enormous amount of death and destruction , Israel’s nuclear deterrent would not be affected at all.

    The real danger is an escalation of the so-called ”crises” about the Iranian nuclear programs leading to war. Dr. Rice has said yesterday that the UN has to act to protect its credibility. So, we are already moving away from the original nuclear issue just like in case of Iraq.

    If this comes to war, then Iran has a ”nuclear option”. They can take out almost all of the oil installations in the Mid East using their missiles. You could imagine that in the run up to a war, Iran would demand that its neighbors stop supplying the West with oil. They would most likely refuse to do that and then Iran would have to destroy the oil installations in response to a US strike.

    The economic consequences of such a strike would be so devastating for the US that it would effectively be ”game over” for Bush.

    Iran’s capability of destroying the oil installations is actually far more powerful weapon (from a military/strategic p.o.v.)than any atomic weapon. The Iranians are thus likely to invest in their missiles, improving the accuracy of their missiles etc. Any investment in an atomic bomb project is just a waste of money for Iran.

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