Flies in the face of the US intelligence community’s report at the end of March [0], but, I am not floored if true. Do you have any sources?
Edit: If you mean "Verification and monitoring in the Islamic Republic of Iran in light of United Nations Security Council resolution 2231 (2015)" [1], that report explicitly mentions up to 60% which is not weapons grade.
This stuff gets grammar-hacked a million different ways.
Yes, 60% enriched Uranium is not weapons-grade, but it can be made weapons grade very quickly. Once you've gotten to 60%, you've done 99% of the work - U-235 starts as such a small percentage of natural Uranium that most of the process is spent at very low concentrations.
It can simultaneously be true that Iran isn't "imminently creating a bomb" and also that they're actively working towards a breakout point where they could build a dozen bombs in very quick succession once they did decide to go forwards with the process.
I don't personally think they were rushing towards a bomb at this moment, but Israel isn't really in the mood to wait around until they decide to do so.
60% enrichment may not be weapons grade, but it takes only days or weeks to go from 60% to 90%. It is much easier than going from natural uranium to 60%.
But maybe a little harshly: Who cares? Does it somehow raise the moral foundation of the operation if they had nukes? Would the attack suddenly be unethical if it was only against a military target with the public, accepted purpose to, one day, be able to develop precursors to nuclear weapons? Why?
Wikipedia points to a source that says it is used for parts of a multi-stage fusion bomb:
> Uranium with enrichments ranging from 40% to 80% U-235 has been used in large amounts in U.S. thermonuclear weapons as a yield-boosting jacketing material for the secondary fusion stage
Just to be clear, this isn't "useful [to make] a bomb" - it's useful in a thermonuclear warhead that already has a primary fission stage using the originally-mentioned highly enriched weapons grade uranium, plus a second fusion stage that (as far as I'm aware) Iran is not working to develop.
edit: phrasing. it feels like we're going around in circles nitpicking based on a poor framing and the tendency for innuendo on this topic
> plus a second fusion stage that (as far as I'm aware) Iran is not working to develop.
All modern nukes are two stage designs, Iran would be insane not to have a fusion stage. It would basically be a Hiroshima style dirty bomb with just 1.5% fissible mass actually fissioned.
I'm well aware of the difference in yield, but I thought a second fusion stage required modeling and testing well beyond basic development? Like I take a quick look at Wikipedia for what devices (for example) India has, and it seems to say whether they contain a significant fusion stage is an open question.
Hiroshima was pretty terrible as it was. And I thought the capability that everyone focuses on because it gets nations a seat at the nuclear table was just basic fission weapons. But please correct me if I am wrong.
> I thought a second fusion stage required modeling and testing well beyond basic development
The bottleneck is UF₆ centrifuges, not the modeling. They're definitely aiming for a fission-fusion design: "The sources note that Iran has attempted to produce deuterium-tritium gas on its own inside Iran - with the help of Russian scientists - but has so far been unable to do so, and due to pressures by the Iranian leadership to accelerate the weapons production program, decided to try to purchase this substance abroad." [0]
India and Pakistan did their first tests ~30 years ago, a lot has changed since then and if you're building a nuke in '25 might as well spend some cash on a simulation cluster and buy some multiphysics simulation software from Russia..
[0] The sources note that Iran has attempted to produce deuterium-tritium gas on its own inside Iran - with the help of Russian scientists - but has so far been unable to do so, and due to pressures by the Iranian leadership to accelerate the weapons production program, decided to try to purchase this substance abroad.
Aren't there some R&D difficulties there? Like that whole fogbank thing the US forgot how to make? I hear trying to obtain deuterium and I figure it's for development and small-scale experiments, rather than an ingredient for a straightforward bomb recipe.
Maybe I'm just putting too much weight on the trials and tribulations of developing the first fusion bombs, and the details of solving or working around those problems is widely known in the right circles these days? Plus advancements in simulation accuracy?
Fuel grade is like 3%. It's exponentially harder to go from 3%-60% (months-years) than 60%-90%(days-weeks). So no, the only reason to enrich that high is to keep your breakout time threateningly short.
Yes brother you are technically correct about that substring of that comment. “Weapons-grade” was indeed not 100% accurate and therefore, technically , inaccurate. That is true, you are right.
That same comment also said, even led with “flies in the face of”. That was the most important part of the comment: ‘saying that Iran is enriching weapons-grade uranium “flies in the face of” intelligence reports which reported no weapons-grade uranium.’ But that part was not correct: the difference between Iran’s uranium (60% enriched) and weapons-grade uranium, while >0, is not large enough to characterize that assessment “flying in the face of”.
So yes if you focus on that substring of the comment you are right. But why would you? It’s not the point of the comment.
Which makes it nit picking. Which is why you’re getting so much pushback.
There’s a lot of misunderstanding around this stuff. Technically all you need for a bomb is the ability to go prompt critical on demand which you can do at surprisingly low enrichment levels. What’s a useful weapons grade enrichment to you has a lot to do with your delivery systems not some universal constant. If you’re looking to fit something in a WWII bomber or early generation ICBM that imposes specific limitations.
Being able to produce weapons grade uranium != producing weapons grade uranium. It's not that complicated.
And yes, in an alternative universe where delivery systems also just appear out of nowhere, you could sprinkle a million tons of 1% uranium over a city.
It’s not about delivery systems just appearing, the logistics of tossing around nuclear weapons in the Middle East using modern technology allows for a vastly larger bombs without significant issues.
Little boy was a logistical issue at the time but only 4,400 kg. You can buy a used A380 for a few 10’s of millions. Convert that to a drone is fairly cheap, and you end up with a vastly cheaper system than the cost of producing a nuclear bomb.
Obviously a subsonic aircraft isn’t ideal, but historic ICBM’s ended up being designed for multiple bombs that’s a lot of leeway if you use the same system to deliver a single bomb. What the US considered weapons grade in the 40’s through the Cold War is based on assumptions that simply don’t apply here.
Edit: If you mean "Verification and monitoring in the Islamic Republic of Iran in light of United Nations Security Council resolution 2231 (2015)" [1], that report explicitly mentions up to 60% which is not weapons grade.
[0]: https://www.newsweek.com/tulsi-gabbard-iran-nuclear-weapon-2... [1]: https://www.iaea.org/sites/default/files/25/06/gov2025-24.pd...