'We Can Enrich Uranium To 80 Percent But We Choose Not To' [Ahmadinejad]

Jerusalem Post ^ | 11 Feb 2010 | AP and JPost Staff

[edpc]

Iranian President Mahmoud Ahmadinejad announced Thursday that the Islamic republic has produced its first package of highly enriched uranium just two days after beginning the process. "We have the capability to enrich uranium more than 20 percent or 80 percent but we don't enrich [to this level] because we don't need it," he said in a speech broadcast live on state television.

"I want to announce with a loud voice here that the first package of 20 percent fuel was produced and provided to the scientists," he said, referring to the recently begun process of enriching Iran's uranium stockpile to higher levels.

[gandalftb]

Theoretically 750 kg. of 20% U233 can achieve critical mass if you can figure out how to implode it perfectly. And, you have to light it off as soon as you reach 20%. And, there isn’t a good retirement plan for the handlers that would be exposed to the very high energy gamma rays.

[gandalftb]

Here is "Restricted Distribution" doc that IAEA issued last night regarding Iran's latest attempt to enrich uranium:

http://www.scribd.com/doc/26733627/IAEA-Iran-20-Report

[gandalftb]

In this doc, Iran states thaey are only beginning a passivation (filtering out reactive elements) cycle, and that they only have one centifuge-cascade.

Iran is also admitting they only have 3.5% UF6 now:

http://www.nytimes.com/reuters/2010/02/09/world/international-uk-iran-nuclear.html?_r=1

[gandalftb]

Great analysis on the issue:

http://isis-online.org/isis-reports/detail/irans-enrichment-for-the-tehran-research-reactor-update/

[gandalftb]

What's a realistic bottom line on Iranian weapons grade uranium enrichment?

If Iran can keep at least one P-1 cascade (164 centrifuges all working together) producing constantly, something they have never been able to do, they can produce at best 18 kg. a year of 20% weapons grade uranium. In theory, you need at least 50 times that amount (750 kg.) to get enough U233 to achieve critical mass.

The kicker is that they have no way to get beyond 20% purity right now and are years away from doing so.

On paper, only, is this entire debate barely rational.

[gandalftb]

For anyone that wants to better understand the nature of weapons grade uranium:

http://www.scribd.com/doc/26735193/U-233

A very readable 1998 doc from Los Alamos, Oak Ridge and Lawrence Livermore Labs.

[Stat-boy]

I have no idea what all this means; thanks for your explanations.

[gandalftb]

In Texas, we would say that Iran was all hat and no cattle.

[Ramius]

What I don’t quite understand is this: North Korea is poorer, starving and technologically way behind Iran. NK is practically pre-industrial. Yes, that’s a slight exaggeration but it isn’t by much. If NK can do it, then I don’t know why Iran so much farther behind. Iran, for all it’s faults and it’s nutty leadership, still has lots of pretty smart folks and lots of money.

Couldn’t it be that we’re being lulled into a false sense of security over their true capabilities? They could be much farther along than they let on.

[JasonC]

Except it is largely about U-233, a different isotope. But sure, along the way it relates some useful information...

[MarMema]

Thanks for the reading material - and what about laser enrichment, which seemed to be what the Iranians twittering
thought last night that nutjob was claiming.

[Snurple]

'We Can Enrich Uranium To 80 Percent But We Choose Not To' [Ahmadinejad]

I can have Keira-Knightley any time I want her....but I choose not too...lmao

[JasonC]

The NK nuclear program relies on Chinese tech; they've been running Chinese built power reactors for decades. You can make plutonium in such a reactor. Iran has a Russian built reactor under construction but not yet operational.

None of these people get there on their own. It is always great powers helping them, for some of the distance at a minimum. For that matter, nobody since von Neumann solved the implosion-lense problem. Everyone since has simply stolen his designs, at one or more removes. A few Russian scientists (e.g. Sakhorov) knew enough to duplicate it if they had needed to, but they didn't. The Rosenbergs stole it.

[gandalftb]

NK wisely chose to enrich plutonium, Iran chose uranium because that is the nuke "family" we started them on when we gave Iran their first reactor.

NK was hooked up with Russia and China who have established plutonium programs.

Plutonium is technically much less challenging to enrich while uranium has a higher potential blast yield and stores better.

[gandalftb]

U233 is the most weaponable isotope as it has the highest blast yield, easiest implosion, and is the most portable. All other fissile materials are compared to it.

[gandalftb]

Any laser enrichment by Iran is experimental only, on extremely small samples. Besides, laser enrichment is only used on extremely pure uranium, generally to get above 80% purity. You have to know exactly what you are shooting the laser at and exactly where, to have any results.

Eventually they will have P2 centrifuges that will work much more quickly than lasers.

Centrifuges are so sensitive, spinning at 80,000+ rpm, that Iran had one completely destroyed by the weight imbalance created by the leftover molecules of solvent used to clean off a fingerprint.

[JasonC]

Wrong. Plutonium leads in all of those respects and by a long way, that is why it is the standard for all nuclear weapons of the major nuclear powers. U 235 - not U 233 - is the second most often used, because it can be produced directly from natural "mined" uranium, whereas production of plutonium requires a nuclear reactor as a neutron source. U 233 is artificially created by neutron bombardment of thorium, much as plutonium is created by neutron bombardment of natural uranium 238. It requires signficantly higher mass than plutonium does to reach criticality, though less than U 235. But the concern over it in the paper linked to is precisely that being less known and used, many international regulations weren't written to apply to it, but it still does need to be controlled.

[MarMema]

Mr. Ahmadinejad also announced that Iran had acquired the know-how to enrich uranium using laser technology, the Islamic Republic News Agency (IRNA) reported. By using laser technology, uranium enrichment could be carried out with higher accuracy and speed, yielding a higher quality product, Mr. Ahmadinejad said. However, Iran would persist with carrying out enrichment using the centrifuges, and not deploy laser technology, the President said.

[MarMema]

Opposition: Iran Using Laser Enrichment

"Jafarzadeh, who heads the Washington-based Strategic Policy Consulting think tank, is credited with having aired Iranian military secrets in the past. But U.S. officials considered some of his past assertions inaccurate. Jafarzadeh urged the International Atomic Energy Agency to immediately send U.N. nuclear inspectors to Lashkar Ab'ad and demand access to all areas, including a new 5,000-square foot hall in a large garden where he said secret laser enrichment activities are being conducted."

[gandalftb]

No dispute, that plutonium is far more popular for many practical reasons. Also no dispute that U-235 is far more available and popular than man-made U-233, again for many practical reasons.

My point in comparing both to U-233 is that U-233 has a critical mass at 16.13 kg, as compared to U-235 at 47.53 kg and plutonium at 10 kg. and that as Uranium, has the "easiest" implosion and compared to both has the highest yield.

16.13 kg. is not significantly higher than 10 kg. and the higher weight of a plutonium bomb makes it less portable. U-233 is the benchmark for weapon yield and deliverablity, but not for its overall practicality and cost.