Pakistan Nuclear Proliferation - 31 March 2005

[Amber G.]

2. How was the HEU for original gun-type fission weapons extracted?

It was electromagnetic separation - (Device was called calutron). Basically it was like a Mass spectrometer - heavy and light uranium ions follow trajectories with different curvatures in a strong magnetic field.

[Alok_N]

2. How was the HEU for original gun-type fission weapons extracted?

It was electromagnetic separation - (Device was called calutron). Basically it was like a Mass spectrometer - heavy and light uranium ions follow trajectories with different curvatures in a strong magnetic field.

Thanks Amber. I have read about it with respect to the manhattan project. was this practice continued into the 50s?

[anil ambani]

2. How was the HEU for original gun-type fission weapons extracted?

It was electromagnetic separation - (Device was called calutron). Basically it was like a Mass spectrometer - heavy and light uranium ions follow trajectories with different curvatures in a strong magnetic field.

Thanks Amber. I have read about it with respect to the manhattan project. was this practice continued into the 50s?

Electromagnetic separation was used to produce HEU for the first U.S. atomic weapon and was recently applied in Iraq. In a device originally called a calutron, heavy and light uranium ions (atoms carrying electrical charges) follow trajectories with different curvatures in a strong magnetic field.

It is not in vogue now a days.
read more specifics on the topic: http://www.isis-online.org/publications ... on_II.html

[Amber G.]

Alok – I think you already know Oak-Ridge Plant employed Diffusion process – Read somewhere that , that and the other (in Washington state) used mega-mega-watts of electricity..
BTW – Russia still has a huge centrifuge industry (Inherited from Soviet Union – their primary way to get HEU was/is centrifuges).
Also some say (have been saying since early 70’s) that laser enrichment will be next basis for enrichment plants. (High-energy lasers can selectively excite the isotopes of uranium., and the resulting ionized atoms are separated electromagnetically. – or - selective infrared absorption of uranium 235 hexafluoride gas is followed by further irradiation at infrared or ultraviolet frequencies, allowing dissociation of the excited molecules or their chemical separation.)
Other techniques are ( research and development stage) - Plasma separation process and chemical exchange process (In France)
Also - the Becker jet nozzle,(Germany and Brazil) exploits the mass dependence of the centrifugal force in a fast, curved flow of uranium hexafluoride.(but that process they say is not commercially viable)

[Alok_N]

Anil and Amber,

Thanks. I am mostly familiar with the basics of these technologies. I can also evaluate to some extent the technical challenges that will be faced by each of them. For example, the separation coefficient in all mechanical technologies is linear in mass. The separative power will then rest on the gradients that can be created, whether in v^2 (centrifuge) or the pressure differential in diffusion.

All of this means nothing unless one is familiar with the everyday problems that are faced by those who work in the trenches ...

the claim here is that centrifuges face technical hurdles that are worse than diffusion pipes ...

a further claim is that all this talk of centrifuge separation is a nice story to scare the kids onlee ...

I would like to know more.

[Amber G.]

the claim here is that centrifuges face technical hurdles that are worse than diffusion pipes

Alok -
As you say, looking at it as a physicist ( deducing from first principle) it is hard to support that claim.

FWIW here are my thoughts

Unlike involvement of laser (or similar techniques); where you selectively ionize (or chemically change) just one isotope and thus, later can use a simpler method to extract one isotope, both of these method, as you say, use “mechanical technologies” and one would think that centrifuge technology can not be worse than diffusion. Although, once one has invested a lot of money and effort (Like US did for diffusion, and Europe/SU did for centrifuge) in setting up plants etc, “other” technology would be “worse” in practical sense.

One piece of data, at present, I am fairly sure, that there is only one commercial diffusion plant in US. (Paducah, KY) The diffusion plant in Piketon, Ohio (which produced HEU for bulk of US bombs in 50's-60s) closed down. Interestingly there is a centrifuge plant under construction in Piketon now.

I would like to know more too.

Added later: American Centirfuge Link

[Sunil]

Hi,

Please lets not digress into a general discussion on U-235 separation.

If these numbers are anything to go by - assuming that the Pakistanis have ~50 bombs with 20 Kg of HEU each. That means the Pakistanis consumed 176 Tons of Natural Uranium. If they had stuck that inside their CANDUs instead they would have generated an s*itload of electrical power.

What a complete waste of Natural Uranium. They have an arsenal of 50 something dirty bombs or 50 something bombs that can't be delivered by anything other than a bullock cart and ineither case they will spend their entire lives in misery hoping that the bombs never have to be used.

What a complete and total waste.

Pillai, why don't you people smelt your HEU/MEU down into fuel bundles and make electricity instead?

[Gerard]

So far, the only relevant answer I have seen is from Ramana who points out that all HEU programs are geared towards fabricating shells for fusion devices.

Can we assume that? Especially in the Paki context?

There have been quite a number of US designs that used HEU (especially very large yield pure fission devices). In other devices the primary pits were composites of Uranium and Plutonium.

While modern US weapons use ovoid Pu pits and spherical HEU jacketed secondaries, these are the result of decades of design experience. While the novice bombmakers would require 10 kg of Pu or 15 kg of U for spherical pits with Beryllium reflectors, US warheads use non spherical pits with advanced wave shaping lenses. Less than 6 kg of Pu is required for their primaries. Can a Paki weapon be compared to such miniaturized US designs? US designers were trying to place as many warheads as they could on their MIRVed missiles.

Paki objectives are much simpler.
HEU allowed faster development. Pak only got their Pu producing reactor going in the late 90s.

[Umrao]

What a complete waste of Natural Uranium. They have an arsenal of 50 something dirty bombs or 50 something bombs that can't be delivered by anything other than a bullock cart and ineither case they will spend their entire lives in misery hoping that the bombs never have to be used.

What a complete and total waste.

Pillai, why don't you people smelt your HEU/MEU down into fuel bundles and make electricity instead?

No saab Pakistan has not wasted any energy on the contrarie its milked the Uranium to the maximum extent with out even making its own bomb.

In the 21 months since 9/11, the United States has poured $600 million in cash, $350 million in military aid and $3.6 billion in U.S. and International Monetary Fund (news - web sites) credits into Pakistan, not to mention postponing payments of $12.5 billion in Pakistani debt to a U.S.-led consortium of countries giving aid to Islamabad. A new long-term aid package is expected at Camp David, including another $1 billion in debt relief.

[Sunil]

Umrao,

I was talking about now - not back when. That was back when - America is not perpetually going to give money for something like this - at some point it will simply become easier to simply take the Pakistani Uranium out of their hands.

Okay so things had to be done at a particular time, now things are different. Any "Son of NPT" should ask for this to be done in Pakistan.

Think about it. Today the Americans are watching those enrichment facilities. if the Pakistanis try any stunts the Americans will bomb those places to bits. Also A Q Khan is in the dock - so no one is going to go around the Islamic world saying "Uranium for Sale, Uranium for Sale".

So why let the national resource go waste? waiting for the Americans to leave so that one can fashion bombs out of it is fantasy... the Americans are never going to leave. And if they leave then they make sure that the U-235 goes with them.

Now is a good time to make fuel bundles and sell the electricity that they make from it. I am sure Uncle will be more than happy to pay for this.

Kya Pillai kuch galat baat bol raha hoon kya main?

Why aren't super duper intelligent and brainy Pakistanis like Gen. Javed Nasir and Gen. Aslam Beg thinking about this possibility?

[Anoop]

Sunil,

As long as the Pakistanis keep the natural U-238 in a stockpile, the US will continue to invest in Pakistan, no? The longer the Pakistanis can delay the conversion to fuel rods, the more the US will pay them not to make them into bombs. Finally when the US tires of paying, they will give the Pakistanis an ultimatum and the Pakistanis, out of long habit, will obey unflinchingly. All this rests on the well-proven belief that the US' first impulse is to bribe rather than confront.

[Johann]

The Chinese test device in 1964 was was an implosion design using uranium, which came as a surprise to the rest of the world. The first Chinese nuclear missile warhead tested back in 1966 (est. yield 12 Kt), transferred to the Pakistanis in the early 1980s was a refined version of the same. Most reports indicate a 15kg solid core (the assumption is that the Pakistanis have to shoot for 20kg in order to produce 15). The Chinese chose uranium because that was the fastest route to the bomb after the Soviets withdrew all assistance to their weapons projects in 1960. Khrushchev had decided that Mao's revolutionary zeal and ideological differences meant he couldnt be trusted not to provoke WWIII once he had the Bomb.

Since AQ Khan spoke both Dutch and German, the Dutch put Khan to work translating the German documentation. He had access not just to design information, but assembly, operation and maintenance as well - balancing, corrosion, etc. Kahuta's output seemed to have improved considerably after they shifted from the aluminium single-rotor G-1s to the steel twin-rotor G-2s. Given that Pakistan didnt actually have to manufacture the centrifuge components further greatly simplified the technical challenge. Kahuta's scale and the G-2s performance (1.2 SWU est) wouldnt allow for a huge fissile material stockpile very quickly, but I dont see why the Pakistanis couldnt make it work since they had so little to work out or build themselves.

[Amber G.]

The Chinese test device in 1964 was was an implosion design using uranium, which came as a surprise to the rest of the world.

For many it was not a surprise, After all, thanks to McCarthyism, Tsien was deported from USA - and China got a lot delivered on a silver platter (Not only in missles/rockets area but other technical areas too). Tsien at one time had access to virtually all US knowledge in this related field. ( classified information and Engineering learnings at Las-Almos) .

[Alok_N]

del

[ramana]

Del.

[Alok_N]

del

[Johann]

Amber,

The surprise was the unusual use of uranium in an implosion design. The Chinese had been expected to use plutonium. The first test of a plutonium design came four years later.

p.s. The Americans didnt want to let go of Tsien, but the PRC made it a condition for the return of PoWs they had taken during the Korean war. Given that he left without his papers, nuclear weapons were not his field, and he lost his clearance in 1950, I dont know what kind of leading role he could have played in the Chinese bomb project.

[Raj Malhotra]

Re Johnan


What is your theory about Pak tests in 1998. i.e. what was tested, how many and for whom. After all ~25kt yield in first test was pretty significant.

What were the yields of chinese bombs on which pak devices were passed, i.e. which were tested in 1964, 66 and 89 ??

[Johann]

Raj,

The October 1964 test yield was estimated by the Americans at 22 kt. They estimated yield of the October 1966 missile warhead test was 12 kt. The deployed weapon was assumed to have a 15 kt yield.

As far as the 28th May test(s) go, 25 kt is higher than non-Pakistani estimates. It remains a mystery to me as to whether one or two devices were tested, and if there were two, whether one failed, or both underperformed. The initial reports from Pakistan itself were two devices, and apparantly there is some seismic data that supports the possibility. If there was a second device, it would make little sense for it to have been entirely identical in every respect to the first. My instinct for what its worth is that the Chinese design performed respectably, and that a second Pakistani modified design drastically underperformed. In particular I cant help thinking about Pakistan's acquisition of tritium extraction facility from the Germans 1985-1987, Pervez Hoodhbhoy's 1996 BAS article hinting at Pakistani problems both with tritium production and delivering a workable boosted fission design, and AQ Khan's boasts after the test that the devices were boosted.

The 30th May test is really much more intriguing. The lack of video or photographs, design claims and general attention from the Pakistanis as compared to Chagai, the possibility of plutonium, and the multiple reports North Korean connection can not be ignored. Why the comparative secrecy? Looking at it from a political and diplomatic angle, presumably because any release of information would lead to highly damaging questions. Pakistan in May of 1998 did not have many friends, mostly in the Middle and Far East, and I think it would have been loathe to risk those relationships unless there was a promise of rehabilitation with the Western led group of nations.

[Umrao]

Now is a good time to make fuel bundles and sell the electricity that they make from it. I am sure Uncle will be more than happy to pay for this.

Kya Pillai kuch galat baat bol raha hoon kya main?

That would be SHOCKING to Pillai and electrifying change for the world.

[Sunil]

Hi Anoop,

Post 9-11 this approach of using the U-238 as a bargaining chip is very risky. The chances of something going wrong are quite high given the huge number Pakistanis sympathetic to the Al Qaida philosophy. Americans should ask themselves a simple question - why take the risk?

Convert the thing into reactor fuel and that should put an end to it.

American experts like Peter Bergen and Tony Zinni can go around the world shouting "Pakistan has more nukes and advanced technology than India" and give the Pakistanis F-16s and that should save Pakistani H&D.

From India's pov. this works out because we aren't going to attack the Pakistanis as long as they have American protection. It is a waste of money - why deal with the mess of Pakistan when the Americans are already heavily interested in doing so? So whether the Pakistanis have more U-235 based nukes is not really our problem.

Plus with all the Puref stuff that the Chinese are supplying to the Pakistanis they are better off with spent fuel anyway. The Pakistanis can then keep dumping the fuel into their Chashma reactors and operate them at low capacity factor (claiming poor quality of components etc...) and keep pulling the fuel rods out before the ratio of Pu-239 to Pu-241 becomes undesirably large. This should give them enough Pu to maintain a credible deterrent or even to conduct "modifications" on the "circuitry on the Chinese supplied M-11s".

Seeing all the obvious advantages for this - I am wondering why brains-trust Pakistanis like Javed Nasir and Mirza Aslam Beg haven't thought about this already.

The only reason that they probably haven't done this is because their Puref tech is not something they want to draw attention to?

[Amber G.]

Johann – I do not know much about history, (that’s why I enjoy your posts) but you and others may find it interesting to read the Tsien affair in detail I had some professors who knew him. To call him a brilliant physicist/Engineer would be an understatement He had a prestigious scholarship from MIT (and later Caltech) When he was at Caltech, he had security clearance – because Von Karman persuaded authorities to grant him a security clearance even before he became an US citizen. It is really a disgrace (and loss to USA) that he was harassed so much by McCarthy and his cronies that he became bitter and left US. The last straw (which some say made him to decide to work against US) came in the much publicized “leaving without his papers” (He asked before hand that they go through his papers and make sure that nothing classified is being taken by him, but he was brutally harassed at JFK by FBI who wanted to search his luggage again - BTW the paper FBI found was a "log table" - anyone remembers those things ? - which caused all that furor! ) was a joke - his memory was superb. China, of course, welcomed him, gave him all the resources he needed (made him head of their missiles programs etc). The reason (or one of the reasons) china did not use Pu, was that Pu is very toxic and they were having difficulty handling it (US experience too - too many workers getting sick/die) with the (then )available technology – besides they had plenty of U (China actually supplied U to SU). (As I said before, his contribution to matters other than missiles- eg atomic wepons design etc - was also fairly significant)

[Gerard]

Production of weapons-grade uranium: Initial IAEA report clears Iran

testing of traces of weapons-grade uranium on the centrifuge parts provided by Pakistan appear to match those found on centrifuges bought by Iran on the nuclear black market headed by Pakistani scientist AQ Khan.

That would strengthen arguments that the suspect traces might have arrived in Iran together with the equipment itself, as the Iranians claim.

[Alok_N]

Production of weapons-grade uranium: Initial IAEA report clears Iran

testing of traces of weapons-grade uranium on the centrifuge parts provided by Pakistan appear to match those found on centrifuges bought by Iran on the nuclear black market headed by Pakistani scientist AQ Khan.

is this statement BS in light of the claims that centrifuges (or, at least paki-fuges) are incapable of enriching U to weapons-grade?

[dwaipayan]

Nuclear bomb blueprints vanish :

http://www.hindu.com/2005/06/10/stories ... 281500.htm

[Raj Malhotra]

Re J

Thanx for your answers.

Now may I take liberty to ask more.

NoK nukes are supposedly derived from Pu. Is this supposed to be power reactor grade diverted Pu or NoK cooked it properly for high quality weapon grade Pu?

[Johann]

Raj,

'Reactor grade' plutonium is what you usually get after reprocessing fuel rods from reactors whose operations were optimised for power generation.

The only purpose of 'research' reactors like Yongbyon (like Khusab and Arak) is to produce as much weapons grade plutonium as they can manage.

Calculations based on IAEA inspections of Yongbyon suggest that 8-15 kg of weapons grade plutonium could have been extracted from the fuel rods unloaded in 1989. Enough for a test device in May 1998, with possibly another one or two to spare if thats what you are wondering.

The reactor was unloaded again in 1994, and its estimated that 25-30 kg of weapons grade plutonium could be extracted from the rods. That fuel was under IAEA safeguards from 1994 until the beginning of 2003. Exactly how much they would need for a weapon depends on what design, if any, they have, but for reference the Nagasaki weapon used 6.2 kgs.

Does Pakistan (and perhaps North Korea) have a design for a plutonium weapon? The director of the US Defense Intelligence Agency testified last year that Khusab was producing plutonium, and that Pakistan's weapons stockpile was expected to grow. A few months later there was the exposure of Pakistani attempts to purchase spark gaps through a South African intermediary. When you also the nature of North Korean-Pakistani relations in the last decade and the questions remaining over the 30-05-98 test, the patterns cant help but appear somewhat suggestive.

Amber, will continue discussion in the international nuclear thread.

[Sunil]

Hmm... so the IAEA has pretty much said that the Iranians are off the hook on the enrichment issue. The Pakistanis too don't have to answer too many embarrassing questions about their AQK side of things. The story has ended. AQK supplied the Iranians with centrifuges and the Iranians did not use them to enrich Uranium to weapons grade.

I was wrong. I thought the Pakistanis would attempt to make their traces significantly different from the Iranian ones so as to present an uncertain picture of Iran's capabilities. It appears that they have done the exact opposite and it doesn't make any sense to me.

Without providing the Americans with an enrichment related stick to beat the Iranians with - the Pakistanis have now effectively sealed the U-235 issue. This could simply open questions about the Pu route which Iran might be interested in.

All in all it makes no sense to me. It is as if the Pakistan-Iran U-235 thing has been effectively shut down.

[Sunil]

Something is not making sense to me.

Either the Pakistanis

1) Have WGU based weapons and a huge stockpile of WGU - therefore the AQK exports are capable of sustaining a HEU weapon.

2) Have a Puref process that is reprocessed.

The Pakistanis had Puref tech at New Labs for a long time. What they lacked was an unsafeguarded reactor to pull fuel rods out of. This reactor at Khusab allegedly began operations in 1998.

The notion that the Pakistanis did not use Pu in their 1998 rests on the idea that the Khusab facility did not become operational till 1998 and consequently no weapons grade Pu could have been extracted in time.

[Gerard]

Why can't they have both?

The HEU program enabled them to build an arsenal quickly. The parallel Pu program was slower off the ground. The Pu test probably used Chinese or North Korean material since the Chinese supplied reactors and reprocessing facilities were not yet producing.

[Johann]

Sunil, i rather depends on what you mean by 'huge'. If you were measuring it in tonnes the range of likely figures would be in the very low single digits. If you are measuring it in potential risk using worst case scenarios, including the failure of American safeguards and contingency plans then thats different

Re. Khusab, reactor operations can be quite easily determined from overhead imagery. There is a marked difference in both the thermal signature as well as simple visual cues such as steam over the cooling tower. Evidence of reprocessing is a little harder to gather - air samples have to be tested for krypton-85. In March of 2000 the Americans leaked that they had found such evidence near Nilore.

[Sunil]

Gerard,

That is precisely what I driving at. The Pakistanis are hiding the Pu side of things.

Anyone who takes the notion of the U-235 based Pakistani bomb and all the risks (JDAM, proliferation etc...) that it entails too seriously risks becoming dangerously complacent.

Johann,

The question I have is could there have been gaps in the surveillance?

I think at this point the risks should be evaluated against a failure of safeguards.

[Alok_N]

sunil,

This entire business of IAEA tests still doesn't make any sense. I smell a huge paki rat.

If things were so straightforward as they turned out to be, why did it take nearly two years to resolve this? It is difficult to rule out the possibility that the pakis sent some carefully manufactured evidence to IAEA ...

my question is exactly what/why was it manufactured?

[Johann]

Johann,

The question I have is could there have been gaps in the surveillance?

by satellite, of reactor operations at Khusab? Very, very unlikely. The Americans had the means and the interest all the way through. It is and was in many ways an ideal intelligence target.

It would be harder to say about reprocessing at Nilore, and environmental sampling required to confirm it, particularly before 9/11.

[Sunil]

Johann,

I am sure the means existed to keep an eye on Khusab. You don't need a satellites there are cheaper ways like a $2 thermometer inserted into the river nearby (you know - like those "concerned environmentalist groups" repeatedly do in the sea near Kalpakkam.)

The Pakistanis for years ran full page ads in the newspapers advertizing their centrifuge tech. and their desire to sell it. It would appear that the implications of this were missed? or perhaps they were deliberately concealed? I don't know.

Alok_N,

I agree something doesn't make sense. The question is what are we missing. The Pakistanis have effectively defused the entire Iranian U-235 enrichment crisis. What does this get them in the great poker game.

[Johann]

Johann,

The Pakistanis for years ran full page ads in the newspapers advertizing their centrifuge tech. and their desire to sell it. It would appear that the implications of this were missed? or perhaps they were deliberately concealed? I don't know.

Actually it was the particularly brazen nature of the KRL glossy brochures at the IDEAS arms exhibition in Karachi for centrifuges and parts in 2000 that began to focus interest on Pakistani nuclear exports, although the efforts were not entirely public.

The degree of difficulty the Pakistani procurement nework experienced in the West, particularly after the May 1998 nuclear tests is what I think caused the shift to countries like Malaysia, South Africa and Russia (whom they managed to get maraging steel out of) in order to meet the needs of their clients.

I think that a more open approach could have helped pre-emptively block those routes, but on the other hand the seizure of parts on the high seas and in factories has led to a chain reaction of embarassment and exposure for Pakistan and the clients of the nuclear procurement network, and I am sure that it was the politically preferrable option. I think what matters is how things progress from this point.

[vinodv]

x-posted:


Iranian nuclear chief admits ties to Pakistan

It's the closest any Iranian official has come to admitting the role Pakistan played in the earliest stages of Iran's nuclear program.

In an exclusive interview with NBC News, the head of Iran's Atomic Energy Organization, Gholamreza Aghazadeh, acknowledged Pakistan's help.

"I do have information that some years ago, through intermediaries, we received pieces for centrifuges," he told NBC News in Farsi.

U.S. intelligence says those intermediaries were part of a network headed by A.Q. Khan, the father of Pakistan's nuclear program. Officials believe Khan earned more than $50 million selling nuclear expertise as well as equipment to Libya, North Korea and Iran. All are on the U.S. terrorist list.

Iran's chief nuclear official tried to downplay Khan's role. Khan confessed a year and a half ago and is under house arrest in Pakistan. But nuclear experts say all roads in Pakistan's nuclear program lead to Khan.

"Khan's help really jump-started the Iranian program," says Corey Hinderstein with the Institute for Science and International Security. "They may have been able to accomplish a centrifuge program on their own, but with the assistance of A.Q. Khan, and the kind of assistance he provided, it really leaped them forward."

The head of the nuclear program said Iran will not give up its nuclear ambitions.

"If there is an understanding that we will give up our nuclear program, that is a big mistake," said Aghazadeh via a translator.

He added that Iran is ready to guarantee it will not pursue nuclear weapons and offer other concessions in exchange for an end to international isolation.

Preston Mendenhall: Does Iran need a nuclear bomb?

Gholamreza Aghazadeh: No.

Mendenhall: Is Iran building a nuclear weapon?

Aghazadeh: No.

Next month, Iran and the European Union will hold another round of talks, monitored closely by Washington. Aghazadeh said Tuesday if those talks don't go well, Iran is prepared to restart uranium enrichment, a process key to producing nuclear weapons.

[Tim]

up. Bad idea to let this one sink to the bottom.

[Umrao]

If Israel is not worried about TS Pakistani proliferation then India should be least worried.
Best is Unkil left to him self worry about that aspect afyet all TS Pakistan is the most flavored allie in GOAT.
And according to some top notch think tanks advising GOTUS should not be penalised but encouraged!!

[Gerard]

US has no evidence implicating anyone beyond AQ Khan