Pakistan nuclear capability, fissile material and sites

Rahul M · Post by **Rahul M** » 31 May 2011 14:46

shiv wrote:
Gagan wrote: I am curious though, why did they say 5 tests onlee and not 7 or 8?
Simply because the first announcement that came out was "two tests. Soon after that the number was corrected to "five".

Funny that Pakistan - which was making implosion bombs using 20 kg Uranium in 1998 - now has the fourth largest arse-nal in the world and nano-nukes to go in tube launched rockets 12 years later. That explains how Pakistan is such a sci-tech powerhouse.

I remember the headline in a bangla newspaper the day after the supposed 6th test "pakistan's 'ace' bomb" (pakistaner tekka bomb) elaborating further that 'pakistan claims that it has tested its 6th nuke to go 1up over India'. catches the mentality quite well.

Pratyush · Post by **Pratyush** » 31 May 2011 14:57

^^^

Like it was some football match. I remember as well. My thinking at the time was, lets hope that the Pakis will become sane now that the Indian & TSP nuke capability is out in the open. We can now have some free and frank discussions.

One year latter the Idiots do Kargil and then they go on to become the down hill sky champions of the world. It has been down hill since then. Yet they dont / can't understand whats wrong with them.

Hmmm...........

Vinash Kale Vipirit Budhi.

Thats how TSP can be summarised

Lalmohan · Post by **Lalmohan** » 31 May 2011 16:02

note all the references to different power supplies, including HV, etc.
sounds very much like a lab experiment than a weaponised system

Gagan · Post by **Gagan** » 31 May 2011 16:12

There is a reason why that article is like a story book.
The guy can't get himself to lie about 5 tunnels and chambers and 5 bombs.
He is scared if he says 5 chambers tomorrow the ISI might be after him because some new complication arose because of him claiming 5. Besides Pakistani officialdom downhill ski. Tomorrow they will reveal that only two were present - one pakistani and one chinese bomb or just the chinese bomb, and he will be asked why he lied about 5 tunnels 5 chambers.

So his and others' description of the bombs will necessarily be vague, human nature about lying is easy to spot.

He will instead try and hide behind patriotism, religion, the common man (hence the lowly on/off switch designer being asked to press the switch)

Gagan · Post by **Gagan** » 31 May 2011 16:20

As it is one can spot bull-shit when one sees it.

This was supposedly a test right? why put 5 bombs in one tunnel in one hill and set them off?
Were they all of the same design? Were they all using similar or different materials?
Did they put a ring of seismic sensors around each?
If they didn't, how on earth were they ever hoping to arrive at the yields of each hain ji?

Simultaneous tests are done in different shafts and tunnels and with each bomb having a separate ring of sensors around them. They are kept separated so that later on there wouldn't be chemical contamination from one test to the other.

The chinese tested their own bomb that day, the pakistanis if they put in one of theirs, it didn't contribute to the yield.

And I think that the lowly switch designing engineer story is false too.

I can't believe that the PLA will allow anyone who is not a chinese soldier and party member to press the red switch. Or the fact that they allowed one pakistani do do it, is the reason why the pakistanis call china their all weather friend.

they let us press the button of their pathaka

What sacrifice, what friendship I say...

Amber G. · Post by **Amber G.** » 31 May 2011 19:31

Wrt to Muhammad Arshad, I think he was rewarded by high honor by the land of pure recently ..(Pride of performance or something like that: google gives this http://www.geo.tv/3-30-2011/79875.htm)

If I am not mistaken, he is the same guy (or his company) who was on US state dept's list (for smuggling triggering devices from Japan and reselling them) long ago and associated with AQ Chor Khan's network.

Don't know if this is the same Arshad..

Lalmohan · Post by **Lalmohan** » 31 May 2011 19:49

if you have five-six bums in the same hill in interconnected tunnels all exploding together, won't the blast waves interfere with each other and produce highly unreadable/unreliable signals?

shiv · Post by **shiv** » 31 May 2011 20:02

I have been trying to look at how much Pu Pakistan can produce in Khusab 1, 2 and 3. Khushab 4 is not yet warm AFAIK. I saw one ref that said that a 1400 MWth reactor will produce 1.4 kg Pu per day. The Khushab reactors are in the region of 50 MWth and if that figure is ported to Khushab each reactor should produce 18 kg a year.

One other ref actually matches this calculation
http://www.fissilematerials.org/blog/20 ... mplet.html

The two new reactor buildings appear to be identical to each other but different from Khushab-I and there has been a debate whether the new reactors are much more powerful than the 50 MWt Khushab-I reactor. However, Khushab-II seems to have cooling towers similar to those of Khushab-I suggesting they are of comparable power. The New York Times reported U.S. government sources as suggesting that "the emerging reactor appeared to be roughly the same size as the small one [i.e. Khushab-I] Pakistan currently uses to make plutonium for its nuclear program."

If Khushab-II is the same power as Khushab-I, and both continue to operate, then Pakistan will be able to double its current rate of plutonium production for weapons. Together the two reactors, operating at 70 percent capacity, would produce about 22 kg of weapon grade plutonium per year.

The plutonium from Khushab-II would become available about a year after the reactor comes on-line, allowing time to irradiate the fuel and then cool it before reprocessing it to separate the plutonium.

Taking this info as correct - we find that Pakistan had about 10 Kg Pu in 1998.

Khushab 1 should have produced (in theory) about 120 kg of Pu by now

Khushab 2 should have produced about 30 kg.

Technically Pakistan should have, by now, about 160 Kg. If that is the case Pakistan may have enough Pu for 15-25 Pu based bombs, or maybe 40 bombs with mixed Uranium Pu cores - a design which what some refs (including one statement from Hoodbhoy) suggest Pakistan uses.

But I have a doubt here. Don't reactors have to be shut down to remove fuel rods for reprocessing? If the reactor is shut down once in 2 years - it should take days or weeks before the fuel rod are cool enough to be removed. After that they need to cool separately for a further year before they can be reprocessed and Pu extracted.

Maybe the reactor core itself can in the meantime be recharged with new fuel and the reactor restarted. But how long does stopping, cooling and restarting a reactor take? I would expect it to take months. Is this correct? Can anyone educate me? If that is the case the amounts of Pu will be even smaller. And there will be at least 20-30 kg Pu sitting right now in pools in reactor rods just cooling.

shiv · Post by **shiv** » 31 May 2011 20:04

Lalmohan wrote:if you have five-six bums in the same hill in interconnected tunnels all exploding together, won't the blast waves interfere with each other and produce highly unreadable/unreliable signals?

Maybe only 1 bum?

ramana · Post by **ramana** » 31 May 2011 20:10

The FAS article shows two spikes in the FFT of the seismogram for Chagai Hills. The spkies are in low frequency range.

shiv · Post by **shiv** » 31 May 2011 20:12

ramana wrote:The FAS article shows two spikes in the FFT of the seismogram for Chagai Hills. The spkies are in low frequency range.

Not simultaneous then?

Added later- ramana - I looked at different images of those seismograms. The two spikes requires a lot of imagination to the naked eye. and may be 10-20 milliseconds apart. Not at all sure if this counts as 2 explosions

Amber G. · Post by **Amber G.** » 01 Jun 2011 00:29

Guddu wrote:
GuruPrabhu wrote:1 tonne = 1,000 kg

1 ton = 2,000 lbs

tonne is also known as "metric ton".

(if ton = 100 kg, I am perilously close to weighing a ton)
Yes you are right in the scientific sense, mine was the colloquial definition per wiki..

"In Britain, a ton is colloquially used to refer to 100 of a given unit...."

Colloquially where I live, 2000 Lbs of Chinese soup is Won Ton.

shiv · Post by **shiv** » 01 Jun 2011 06:48

I post this link to show why a non state jihadi delivered atomic munition (non state JDAM) is impossible. if a nuke is exploded it must have sanction of what passes for the Pakistani state and Pakistan should be made to face the consequences. China will need to take part of the fallout. Pakistan cannot hide behind the burqa of "non state actor"

http://www.nci.org/k-m/makeab.htm

GuruPrabhu · Post by **GuruPrabhu** » 01 Jun 2011 08:34

Amber G. wrote:Colloquially where I live, 2000 Lbs of Chinese soup is Won Ton.

And it is served in a place with an open door policy: Wok Inn.

But all seriousness aside, I would be interested in hearing more insights into Paki establishment -- one of your links to posts long ago indicated that you had the occasion to spend time in that rat's nest.

"How much is a barn?", as I recall.

How can any sane person actually believe that these yahoos can make a newkiller bum?

by the way, one of the largest neutron absorption cross sections known to science is for gadolinium -- about 50 kiloBarn. Try explaining to a Paki that he needs 50,000 barns lined up with doors wide open, in Wok Inn position, and try to close all doors before that gadolinium nucleus infiltrates the holiest of the holy.

Gagan · Post by **Gagan** » 01 Jun 2011 17:33

Pakistan's Missile & Ordinance Factories

Pakistan has a fairly extensive defense industry, which is located mainly between Islamabad and Kamra. There are a string of ordinance and missile factories in this area. Some of the main factories are:

1. National Defence Complex, Fatehjang: Missile, TELAR and missile related electronics, nuclear weapon components, Ordinance.
2. Talagang Missile Complex: Missile manufacture and storage.
3. Tarnawah Missile Complex: Missile manufacture and storage.
4. Pakistan Ordinance Factories, Wah: General ordinance for use by the Pakistani Armed Forces.
5. Air Weapons Complex, Kamra: Air dropped weapons, fuses, nuclear weapons related components.
6. Gadwal Uranium Enrichment Plant: Chinese built Uranium enrichment and moulding.
7. Heavy Industries Taxila (HIT): MBT, APC & Armoured Vehicles manufacture.
8. Heavy Mechanical Complex (HMC): Iron & Steel forgings, engine parts etc.

________________________________________________________________________________________________________

National Defence Complex, Fatehjang

The NDC set up in 1990, and usually headed by PAEC chairmen, manufactures several defense related products.
The list includes:
1. Missile components and TELARs
2. Various anti-tank warheads, fuel air explosives, naval mines.
3. Military fuses and defense electronics
4. Nuclear weapons components.

Main Administrative Buildings

Complexes 3, 4, and 5
Complex 4 & 5 have come up over the last 5-7 years.

TELAR manufacture and Garages

Pakistan uses several trucks which are Chinese copies of the Russian and Ukranian heavy lift trucks.
The main trucks are:
1. Wanshan WS-2400: 8x8 20 ton capacity. Used for the DF-11 missile, early Shaheen-1 missile TEL, A-100 MLR and the Nasr MLR. Chinese copy of the MAZ 543.

2. MAZ 547 / 7916: Which carries the MRBMs

In the picture one can see a few MAZ 547 / 7916s

This complex, which I have arbitarily named as complex 6, seems to have special security as seen by the high walls and guard towers. This complex is a few kilometers to the west of the Main Complex.
What are they specially protecting? Is this facility an N-weapons related facility given the extra security and the distance from the main complex?

These appear to be garages, storage areas and a military garrison. This is adjacent to 'Complex-6'

South of the Kala-Chitta hills, towards Fatehjung town, is a dam and a lake. There are two more areas on the banks of the lake. An explosives manufacturing plant and another adjacent complex, where a large hole is being dug adjacent to some sheds.

________________________________________________________________________________________________________

Talagang Missile Complex

This is a facility located about 50 Kms west of the National Defense Complex on the same Kala-Chitta hills range. The location is just south of Attock Cantt.
This seems to be a missile manufacturing and storage location. Compared to the main NDC this area has a ring of AAA, Skyguard radars and a SAM site protecting it. It is possible that this is a location for storage of both Nuclear weapons and MRBM missiles.

Main Complex

A TELAR is visible adjacent to one of the hangers

MT pool is a truck parking garage.
Military lingo.

There is a Skyguard site on the hill located at 6 O' clock.

This seems to be a test area. A test rig, large hangers and several TELARs are visible here.

These appear to be Helipads / Missile launch sites.
This area is to the south of the main complex at the foothills.

Skyguard Radars and AAA sites around the complex
Courtesy Planeman.

________________________________________________________________________________________________________

Tarwanah Missile Complex

Located north of Fatehjung, and adjacent to Islamabad is this facility that is suspected to manufacture Chinese origin M-11, M-9 and M-18 missiles, renamed as the Shaheen series of missiles. These are all solid fueled missiles.
The complex has two areas a few kilometers apart.

Tarwanah Missile Complex 1

Main Administrative buildings and missile components factory.

Dynamic test rigs

Storage hangers

Tarwanah Missile Complex 2

Possible storage area

________________________________________________________________________________________________________

Nodong / Ghauri Missile Plant Kahuta

As mentioned in a previous post, these North Korean Liquid Fuelled missiles are manufactured at Kahuta.
Kahuta itself has three different facilities:
1. Uranium Centrifuge Plant
2. Nodong/Ghauri missile plant
3. Ordinance factory: Anza Manpads, fuzes, electronics.
The Nodong/Ghauri missiles made here are usually tested from the nearby Mahshood Testing Range at Tilla Jogiyan near Jhelum.

Gagan · Post by **Gagan** » 01 Jun 2011 17:51

Pakistan Ordinance Factories, Wah

POF, Wah is Pakistan's main armaments manufacturing concern. The complex has 21 odd plants manufacturing around 70 products, ranging from general ammunition and infantry weapons.
An exhaustive list is available in the wikipedia page: Pakistan Ordnance Factories

Main Factories and Administrative area

More factories and storage area

Storage bunkers

Gadwal Uranium Enrichment Facility
Set up by the chinese, unsafeguarded facility for uranium gas centrifuges. Also seems to have a plant for moulding metallic Uranium.

__________________________________________________________________________________________________________

Air Weapons Complex, Kamra

This facility located adjacent to POF, Wah, manufactures various air-launched weaponry, defence electronics and aircraft electronic components including avionics.
It is also suspected to be a Nuclear Weapons related site.
This facility has been the subject of a Taliban/Al-Qaida attack a few years back, where the main gate of the facility was blown up by Jihadis in an attempt to enter the facility.

Storage area close to the Air Weapons Complex. This is heavily wooded, and has a deep ravine running through it with several hardened bunkers within the ravine. The site has a security wall with several guard posts. It is possible that given the security this might hold nuclear weapons related components.

shiv · Post by **shiv** » 01 Jun 2011 20:16

Have patience folks. There is method in my madness.

My current quest is to see how far deterrence can be based on a bluff. I had started an entire thread in this regard - but that was in the context of India's deterrent. I am looking at Pakiland here. Specifically to examine the probability of Pakistan having developed a less than 30 cm diameter tactical nuclear warhead to be used with Nasr as a foil to "Cold Start"

The key to me at this point in time is the "less than 30 cm" diameter limit for a nuclear weapons but the larger point that I would like to look at later is whether Pakistan will field tactical nukes of any sort. I am harping on the feasibility of Pakistan making a < 30 cm nuke because I believe that if it is unlikely - they are just bluffing and the bluff will be caught by those who are in the know - let alone total outsiders like me. So I am on a quest to see the likelihood of Pakistan having developed a 11 inch warhead for tactical use on the Nasr via whatever indirect publicly available information I can gather.

There are two simple answers that we can start with
1. Nations like the US and USSR did develop tactical warheads as small as 5-6 inches in diameter to be used in artillery shells and anti-aircraft missiles. So it is technically possible.
2. China has the technology and gives it to Pakistan.

Using this information as proof that Pakistan has small 11 inch warheads is like saying "The US has developed the F-117, F-22 and F-35. China is developing the J-20. Pakistan can be assumed to have a stealthy F-22 class fighter" If we do not believe that we really should be asking if we can believe that Pakistan has warheads that are 11 inches in diameter. I have no argument against this logic and consider myself alone in being skeptical if this logic is "accepted knowledge"

Note that there is absolutely no earthly need for Pakistan to develop a 11 inch warhead. they could just as well have a proven Chinese design - place it on an existing missile deep inside Pakistan and fire it on Indian forces for cold start. So the idea that they will have to use "Nasr" with its 30 cm diameter for a "tactical nuke" - after putting the missile on the frontline within 50 km of India is decidedly odd. Why struggle with 30 cm when you have missiles that can carry larger warheads?

But can Pakistan develop a working 11 inch warhead? My judgement is "Yes". Workable, if not working. After all I too can build an aircraft. It may not fly. Making it fly would depend on my technical skills and the material and engineering capability I can bring to bear on it.

After all a nuclear warhead is all about compressing a lump of suitably pure fissile material so it goes bang. The compression is usually a conventional bomb whose energy is directed towards the fissile material to compress it. The closer the fissile material is to its "critical mass' the easier it gets to compress it to produce a bang, but the more dangerous it is to handle. The publicly stated method reducing the amount of fissile material used up and making it safer is to use a blanket called a tamper. The lightest and most efficient tamper material in public sources is Beryllium. Pakistan was not a Beryllium producer but may be one now. They did however import some from Germany. But it need not be Beryllium - it can be something else - like Uranium which Pakistan has.

So if you make a bomb core with some Pu in the center and surround it with some tamper - the Pakis have only 11 inches to play with. There is no public information about the thickness of tamper needed - but it is likely that about 4 inches (maybe more) out of 11 inches will be used up for fissile material and tamper. That would leave a bare 3 inches on either side of the core for the explosive and other material that is needed to compress the Plutonium to produce a nuclear explosion.

If you were Unkil of 1950 you would calculate what you need to do and then take the damn thing to Nevada or wherever and test it to see if it produces any useful yield. But what would you do if you are a Paki. You can't do a live test so so how do you ensure that the damn thing explodes?

If you were a sensible Paki you would not set yourself this stupid 11 inch limit. You would say "Bugger it - I want my warhead to explode. Balls to 11 inches diameter. i will make it 22 inches diameter and blast the crap out of those piss drinking kafirs to the east"

If ISI held a gun to your head and said "You fuken munafiq - make it 11 inches or else.." what would you do? I don't know. I am no bomb designer - but I am guessing that i would use the maximum amount of fissile material in that core - maybe 6 kg or even more of Pu so that a minimum amount of compression would get some yield of at least a few tens or hundreds of tons. This design would make it costly in fissile material - a very small bang for a very large amount of Pu.

So yes - I am sure Pakis can produce some warhead that fits into a Nasr but I think it is unlikely, unwise and costly in fissile material if it is to be reliable. Considering that Pakis could have threatened the use of existing large nukes to thwart cold start I think it is a bluff when they tested Nasr and claimed they have a 11 inch warhead for Nasr. They used the test of Nasr to make a claim that they had warheads to fit that missile.

Why are the Pakis bluffing about a non existing nuke? Clearly they are not sure of their deterrent. More on this line of thought later.

VikramS · Post by **VikramS** » 01 Jun 2011 20:23

One thing I do not understand. Why did they limit the diameter of the NASR.

If they can create something with 30cm diameter, it does not take a lot of work to make it slightly larger (say 40 cm) if it serves the purpose.

Perhaps it is an indication of hollow their engineering base is. Apart from painting, they can do little to adapt the shipments to suit their needs.

All that nuke power non-sense from the West might just be a facade to keep the =/= going. But the whole problem is that you never know. And that is what the TSP survives on; the fear of irrational response.

ramana · Post by **ramana** » 01 Jun 2011 20:41

VikramS, it could be based on dia of delivery vehicle which also could be PRC origin material.

shiv · Post by **shiv** » 01 Jun 2011 20:42

VikramS wrote:One thing I do not understand. Why did they limit the diameter of the NASR.

If they can create something with 30cm diameter, it does not take a lot of work to make it slightly larger (say 40 cm) if it serves the purpose.

Perhaps it is an indication of hollow their engineering base is. Apart from painting, they can do little to adapt the shipments to suit their needs.

All that nuke power non-sense from the West might just be a facade to keep the =/= going. But the whole problem is that you never know. And that is what the TSP survives on; the fear of irrational response.

Vikram the Pakis have missiles which can carry bigger warheads. The Nasr is probably an adaptation of an existing Chinese tube launched missile. They tested one and said "We are going to nuke Indian cold start forces with this"

RamaY · Post by **RamaY** » 01 Jun 2011 20:52

Could it be that Pakis are trying to throw dirty bums with a mix of conventional and low-grade U; calling it tactical nukes? would it cause any significant damage on an advancing column?

Lalmohan · Post by **Lalmohan** » 01 Jun 2011 21:24

^^^ no not really
it would be very dumb, because it would cause minimal damage to IA, and invite full retalliatory strike

Amber G. · Post by **Amber G.** » 01 Jun 2011 21:46

GuruPrabhu - Wrt to barn in the rats' nest, I don't know what you are talking about

, ... it was long ago anyway, .. that too for a short time, ..and besides others too have done that.. also one can plead fifth...

Wrt to barn, I am sure you know, the origin was due to initial surprise at the large cross-section of U. Some one remarked it was " as big as a barn" (later, Americans kept the term hoping that this slang name would obscure its relation to anything nuclear and keep it from prying eyes)

I am not sure, if many know it here (for those who have not read it, try google for old news - 70's -80's for details .. news became quite public) that Paki (Embassy in US) actually tried to offer a million dollars to a Princeton undergrad, who wrote a paper about nuclear thingie for his senior thesis.

(The student reported it, and FBI etc got involved and media got the story ) .

I think Shivji is letting a good opportunity go, by publishing pictures of Swan designs and what not, in an open forum for free. I bet Pakis will pay good money for that.

Coming back to the rat's nest, people tell me that:
All physicists in the land of the pure, who are good enough to get a research position at a reputable university in US, could be counted on probably fingers on two hands. The younger generation (consisting of top grad/undergrad students who apply outside Pak) does not impress either.
Personally I do not believe that Paki engineering can make/improve/tinker/adjust any triggering device and such..

UBanerjee · Post by **UBanerjee** » 01 Jun 2011 23:31

Frankly, it seems as if a good 75% of the hooplah surrounding Pakistan's nuclear capabilities is just smoke and mirrors. It's something that survives because people keep repeating it.

Nuclear weapons are the ultimate products of an advanced military-industrial complex. They are not something which can be really made or developed by small cottage industries. Pakistan's manufacturing capabilities of even civilian high-tech stuff are miserable. Their domestic arms industry consists of spray-painting Chinese goods and calling them "indigenous". So their nuke "industry" is just the same, a pure facade over Chini materials with basically 0 domestic capacity to tweak, upgrade or develop. They don't have the pure sciences base or the engineering and manufacturing capacities.

The entire effort is a desperate image exercise to keep up with the Jones, not any actual interest in working defense- you know, the reason a normal nation develops nuclear weapons is to actually have a working industry that can aid defense in a real way. E.g. Israel- speak softly and carry a big stick. With Pakistan it is speak very loudly about your tiny stick and how dangerous you are.

The reason these exaggerations survive is because for rational nations, such as India, it pays to be cautious and give the benefit of the doubt.

Amber G. · Post by **Amber G.** » 01 Jun 2011 23:33

by the way, one of the largest neutron absorption cross sections known to science is for gadolinium -- about 50 kiloBarn.

Did not know that..! All we talk about before was stuff like hafnium and cadmium... Thanks.

Now, all they have to do, to make it fit in 30 cms, instead of using Ga (for plutonium-gallium alloy), mix Pu with gadolinium titanate...

shiv · Post by **shiv** » 02 Jun 2011 05:39

Amber G. wrote: I think Shivji is letting a good opportunity go, by publishing pictures of Swan designs and what not, in an open forum for free. I bet Pakis will pay good money for that.

Well clearly I am among the most highly qualified people to speak of nuclear weapons on BRF considering that the gaps in my knowledge could accommodate a barn and anyone who mistakenly believes a barn has anything to do with atoms is disqualified. Back to school. I mean you know atoms are small - like the head of a pin, or even human hair. That is small. Barns are big. Big as horses. ..and all

shiv · Post by **shiv** » 02 Jun 2011 06:08

UBanerjee wrote:They don't have the pure sciences base or the engineering and manufacturing capacities.

A couple of years ago I tried to look at what info I could get about this - especially university programs etc in Pakistan - but the material available is rubbish.

If you sit in front of a computer with internet and have a choice between becoming a self-made educational advisor to Pakistan and self made atomic weapons expert, it is far easier to become the weapons expert.

But plenty of anecdotal and circumstantial evidence exists to describe the state of Pakistani science and industry. Pakistanis have been bluffing too long. Bluffing has become an end in itself. Everything is explained by bluffing. I may not necessarily do "scientifically rigorous" research but I can certainly make some general sociological observations from the comments that some of my YouTube videos attract from Pakis. These are comments from a subset of Pakis who can understand English - even if their replies and comments are in Urdu/Punjabi using English alphabet. The have been brought up on lies, lies and more lies.

shiv · Post by **shiv** » 02 Jun 2011 07:56

http://nuclearweaponarchive.org/Pakista ... senal.html

Last changed 6 August 2001

Weapons Stockpile

The uranium enrichment facility that produces most of Pakistan's weapons material )(highly enriched uranium or HEU) is the gas centrifuge plant at KRL (A.Q. Khan Research Laboratories) at Kahuta, 50 km Islamabad. This facility, which employs 7,000 people including 2,000 scientists and researchers, began operating in the early 1980s, but suffered serious start up problems. A.Q. Khan announced that Kahuta was producing low enriched uranium in 1984. US intelligence believes that uranium enrichment exceeded 5% in 1985, and that production of highly enriched uranium was achieved in 1986. Kahuta has run essentially non-stop at enriching uranium since that time (though with varying numbers of gas centrifuges). At start-up Pakistan had reportedly manufactured 14000 centrifuges, but had only 1000 operating. By 1991 about 3000 machines were operating according to US intelligence. This implies a production capacity of 45-100 kg U-235/year depending on the tails concentration and production efficiency, enough for 3-7 implosion weapons. Shahryar Khan has said that the cost of Kahuta was relatively modest, less than $150 million[Albright and Hibbs 1992].

U.S. and former Pakistani government officials have said on many occasions that Pakistan voluntarily halted production of HEU at Kahuta in 1991. But instead of shutting down the plant, Pakistan simply reconfigured their enrichment cascade to produce low enriched uranium (LEU), thus continuing to perform the same amount of separative work. Since the production of this "middle product" between natural and highly enriched uranium requires most of the separative work required to produce HEU, this in effect stockpiled separative work units (SWUs) that Pakistan could recoup with comparatively little additional effort at a later time to produce HEU without loss in cumulative production in the end. Pakistan is known to have resumed HEU production no later than 1998 after the nuclear tests conducted that year (and possibly well before), thus the production of HEU forgone between 1991 and 1998 has been made up by now (probably before the end of 1999), and the effect is as if HEU production never halted.

Pakistan has built a second enrichment plant at Golra, 6 miles from Islamabad. It is expected to be even larger than Kahuta, with more advanced centrifuges. It may not yet have begun production though due to difficulty in obtaining the necessary parts now. In March 1996 the New York Times reported that China had sold Pakistan 5000 ring magnets suitable for use in gas centrifuges.

It is estimated that Pakistan produced about 210 kg (range 160 - 260 kg) of HEU up to the moratorium in 1991 [Albright and O'Neill 1998]. The current production capacity of Pakistan is approximately 110 kg per year (range 80 - 140 kg/year), and the cumulative production of HEU (less the HEU expended in the 1998 tests) is estimated at about 800 kg at the end of 2000 (range 665 - 940 kg) [Albright 2000]. Since a uranium weapon requires about 15 kg this equates to a potential for 53 weapons (range 44 - 62), although somewhat more than 15 kg may be used to produce more powerful and efficient weapons.

In April 1998 the unsafeguarded Kushab reactor began operating. This reactor is a heavy water-natural uranium reactor built with Chinese assistance and has an operating power of 50-70 MW. This reactor should be able to produce around 10-15 kg of plutonium a year at a 60-80% load factor (the fraction of the time the reactor actually operates) [Albright 1998b]. Through the end of 2000 approximately 10-28 kg is estimated to have been separated from the fuel, a figure that is strongly affected by how quickly the fuel is processed after irradiation, and the effectiveness of the separation plant. Pakistan has a pilot plutonium reprocessing plant called "New Labs" at the Pakistan Institute of Scientific and Technical Research (Pinstech) complex near Rawalpindi. Reportedly the New Labs facility was expanded during the 90s to handle the full fuel load from Kushab. CBS News reported on 16 March 2000 that US intelligence had found evidence (such as krypton-86 emissions) that Pakistan is reprocessing irradiated fuel from the Khushab reactor and recovering separated plutonium [Albright 2000]. Fission weapons require 4-6 kg of plutonium, so 2-7 weapons could have been manufactured from this material.

In addition to Kushab, Pakistan is also manufacturing reactor-grade graphite and has its own heavy water plant both of which may be used to build additional plutonium production reactors fueled with natural uranium. It currently possesses two power reactors - the Karachi Nuclear Power Plant (KANUPP) with an output of 137 MW electrical, and the Chasma Nuclear Power Plant (CHASNUPP) with an output of 300 MWe. CHASNUPP is a pressurized water reactor constructed by the China National Nuclear Corporation was completed in late 1995. CHASNUPP began operations in November 1999 and was connected to the power grid (run by the Karachi Electric Supply Company) on 14 June 2000. These reactors have produced 600 kg of plutonium in their spent fuel but this plutonium remains unseparated and under IAEA safeguards.

The Kushab reactor could also be used to produce tritium for boosted weapons. The production capacity for tritium would be on the order of 100 g per year if enriched uranium is used as fuel, enough to boost perhaps 20 weapons. Pakistan is known to be interested in tritium, having acquired a tritium purification and production facility, and 0.8 grams of pure tritium gas from West Germany in 1987, as well as even larger quantities of tritium from China.

According to A. Q. Khan, as well as other Pakistani scientists, the devices tested in 1998 were most of all boosted weapon designs. Pakistan has not tested a true staged thermonuclear device. This implies that Pakistan can built pure fission or boosted fission devices with yields ranging from sub-kiloton up to perhaps 100 kt. Higher yields are possible, but suffer from the delivery weight limits of its existing missiles and probable limits to Pakistani miniaturization technology. China has provided a complete tested designs for a 25 kt pure fission weapon.

shiv · Post by **shiv** » 02 Jun 2011 08:14

I am putting the following line here for my own reference although most of it is gobbledygook to me. But it says how a competent bunch could reduce the amount of Uranium needed for a bum from 50 kg to 6 kg.
http://www.nuclearnonproliferation.org/ ... terial.pdf

"Compressibility of Uranium and the Minimum Quantity for a Fission Weapon
Ara Barsamian
Nuclear Non-Proliferation Institute; Morris Plains, NJ 07950 USA
http://www.nuclearnonproliferation.org

"

Amber G. · Post by **Amber G.** » 02 Jun 2011 08:51

Back to school. I mean you know atoms are small - like the head of a pin, or even human hair. That is small. Barns are big...

I am sure you know it, but just in case.. Barn is an unit of area (10^(-28) m^2).. and yes (one can check out wiki - if there is doubt

)the term barn was at one time classified..
The cross section area of U was a (which one can find in any text book now) very closely guarded secret, and it may still be classified.. (exact values at various energies of neutron) ...

shiv · Post by **shiv** » 02 Jun 2011 09:12

Amber G. wrote:
Back to school. I mean you know atoms are small - like the head of a pin, or even human hair. That is small. Barns are big...
I am sure you know it, but just in case.. Barn is an unit of area (10^(-28) m^2).. and yes (one can check out wiki - if there is doubt )the term barn was at one time classified..
The cross section area of U was a (which one can find in any text book now) very closely guarded secret, and it may still be classified.. (exact values at various energies of neutron) ...

I think you had made a post about this earlier in the thread. No. No doubts about it, but people like me who are the real experts are not supposed to know all this. it will cloud my mind and overload it with minor details.

You see - atoms are small - nuclear weapons are big. How can nuclear weapons and atom size have any connection?

..only joking of course - but not knowing much makes it easy to say anything.

GuruPrabhu · Post by **GuruPrabhu** » 02 Jun 2011 16:35

Amber G. wrote: The cross section area of U was a (which one can find in any text book now) very closely guarded secret, and it may still be classified.. (exact values at various energies of neutron) ...

It is public now:

Amber G. · Post by **Amber G.** » 02 Jun 2011 18:06

^^^ At first I though, like Shivji you too are doing a great disservice, and missing a great opportunity of making a million dollars or so by not selling the link to ..Paki Embassy in DC...

But then I realized that the above graph has
- Redacted data - look around 2 eV (about 4 times the energy of electron in s-shell). No way to look at it and get the value to 3 sig figures.

- The graph cuts off around 20 Mev (nice teaser) well before 200 Mev! (Everyone knows about non-linear graphs these days)

(I have in the real deal, left to me by one Mr. Abdul Abdul, who died in car accident while traveling in Nigeria)
----
Wrt to above ....I once remarked, "are you serious, it's in every text book" to a prof (guy worked in Manhattan project) while eating our lunch, and was told very accurate values are (or were then) still classified. Don't know if he was kidding or serious but there was an old sign still hanging in the cafeteria (this was inside a national lab)."Discussing any classified material in this area is prohibited ..blah..blah.. and publishable up to 10 years in federal prison"..( (I am not making it up

.

GuruPrabhu · Post by **GuruPrabhu** » 02 Jun 2011 18:26

Amber G. wrote:But then I realized that the above graph has
- Redacted data - look around 2 eV (about 4 times the energy of electron in s-shell). No way to look at it and get the value to 3 sig figures.

Yes, for Mango Abdul, there is no way to verify this or extract accurate numbers. But then, the geniacs at Kahuta would not know how to use it anyway -- one needs an accurate simulation of the neutron energy spectrum in order to make use of this graph.

[btw, I have heard from top secret sources that painting a cheeni bum green does not require knowledge of the u-235 cross section

]

Lalmohan · Post by **Lalmohan** » 02 Jun 2011 18:52

i hope they are not using lead pigments in their green paint
will reduce the yield significantly...

Amber G. · Post by **Amber G.** » 02 Jun 2011 19:01

I have heard from top secret sources that painting a cheeni bum green does not require knowledge of the u-235 cross section

True, but we are not talking about any old green color.. I have the top secret hyperfine Zeeman spectrum 5461 Angstrom of mercury. That is still a top secret... not available for free.

Ok - last one - back to serious business..

shiv · Post by **shiv** » 02 Jun 2011 19:12

Lalmohan wrote:i hope they are not using lead pigments in their green paint
will reduce the yield significantly...

No. Lead tamper of 0.2 mm thickness will save 5 grams of Pu. A penny saved is a penny earned hainji?

Amber G. · Post by **Amber G.** » 02 Jun 2011 20:01

^^^Pb is old news...
I did wiki after GP's mention of gadolinium
at http://en.wikipedia.org/wiki/Gadolinium And found:

Gadolinium compounds are also used for making green phosphors for colour TV tubes and compact discs.

Perfect!

Also, we can sell them some Cd to mix it up with their U235 ..(Mix yellow with Indian Blue to produce green).. ( and, ..some are mocking those "exploding PV's"

)

shiv · Post by **shiv** » 03 Jun 2011 07:23

shiv wrote:I am putting the following line here for my own reference although most of it is gobbledygook to me. But it says how a competent bunch could reduce the amount of Uranium needed for a bum from 50 kg to 6 kg.
http://www.nuclearnonproliferation.org/ ... terial.pdf
"Compressibility of Uranium and the Minimum Quantity for a Fission Weapon
Ara Barsamian
Nuclear Non-Proliferation Institute; Morris Plains, NJ 07950 USA
http://www.nuclearnonproliferation.org
"

Question to AmberG, GuruPrabhu or who ever else wants to take a shot at this:

The above paper says:

Soviet scientists, particularly A’ltshuler and Zababakhin [1] refined the art of implosion
by recognizing that isentropic compression could produce much higher densities than the
straight shock driven implosion, and they developed the technology used in their nuclear
weapons program in late 40’s - early 50’s, using multilayered graded impactors. This
technique was refined in the US in the mid 50’s and early 60’s, making possible density
increase by a factor of three, thus doubling yields, or the converse, using less fissile
material in so called “fractional crit” weapons.

In the case of Iran, using 93% HEU metal bare sphere with Mc of 52kg, isentropic
compression by a factor of 3 decreases the critical mass by a factor of approximately 9 to
about 5.8kg, and for delta phase Plutonium metal sphere, from Mc of about 16kg to about
1.8kg. To get a yield, you need a super critical mass, so add another 10%, for a total of
6.5 kg HEU and 2 kg Pu respectively.

How credible, feasible or easy is this "isoentropic compression" ?

Amber G. · Post by **Amber G.** » 03 Jun 2011 07:48

Hi Shiv -

I will take a stab.. (Take it for what ever it worth

- I will not go in details) (From what I know with basic physics principles and reasonable guess)

WRT to U235 (or HEU) , the interesting quantity (for Pak) is about 15 Kg. They can't make it less. OTOH with this much (or a little more) of U the probability that they can make it go, is something we should worry about and keep our eyes open. (IOW, it could be that much less, even with primitive triggers)

Smaller amount (or Pu ) is highly unlikely. (It is like compressing water with hands/fingers without letting the water slip through your fingers).