Casting doubt on Indian nuclear weapon designs and yields

shiv
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Casting doubt on Indian nuclear weapon designs and yields

Postby shiv » 22 May 2008 07:27

An earlier series of threads about nuclear issues in India was shamefully peppered with insulting and defamatory language that was ostensibly "well intended" to prove a point.

One point that was discussed was whether India's nuclear weapons will really provide the claimed yields, and whether they can really be expected to be as light and sophisticated as is generally assumed. Obviously if the weapons are less sophisticated, they get less bang for buck, and more fissile material is consumed in larger and relatively unsophisticated fission warheads. The result of this is

1) Heavier warhead - smaller range of missile, fewer MIRV warheads
2) More fissile material used, smaller weapon inventory.
3) Less sophisticated warhead, smaller yield, more warheads needed for a specific goal.

There are two issues to the debate, and while I list them, let me repeat what I said when I closed the thread earlier. I am demanding that only one of these two issues is discussed here. I will indicate which one.

Issues involved:
A) Credibility, integrity and patriotism of scientists and politicians in India
B) Real technical issues relating to testing, simulation and weapon design.

Mixing up these two issues has been the source of considerable ill-will. Every technical doubt has been sought to be addressed by calling into question the credibility, integrity and patriotism of someone or the other. R.Chidambaran said xyz. R Chidambaram is a liar. Manmohan Singh said blahblah. Manmohan Singh is a traitor.

This is a dead end game. Technical issues cannot be resolved by variably and randomly questioning the credibility, integrity and patriotism of every protagonist. For convenience let us assume that everyone - all scientists, all politicians, everyone in the armed forces, all analysts, all members of BRF and indeed all Indians are equally b**nchods who are liars, traitors who would sell India out in exchange for a half-smoked beedi. Or even free for that matter - to please some foreign master. Not even that half-smoked beedi.

Once that issue is resolved we can go ahead and speak of issue B: " Real technical issues relating to testing, simulation and weapon design."

Let me put down some core issues off the top of my head:

Ten years ago (1998) India allegedly conducted five nuclear tests. Three were claimed to have been conducted simultaneously on May 11th and two more on May 13.

The yields of the May 11th tests were questioned by firangi observers but were claimed by Indian testers as being somewhat higher. One warhead was claimed to be one boosted fission warhead of 45 kilotons and if I recall right, one was a fission bomb of the type tested in 1974- but this time in the avatar of a deliverable warhead. The May 13 tests were seismically undetectable and were claimed to be subkiloton tests.

Soon after the second set of tests was over it was claimed that there was a sixth warhead that was ready to be tested, but that warhead was not tested but was instead retrieved from underground because all testing objectives had been met.

The yields of those tests have been called into doubt by many people, but have been supported by others. Arguments and counter arguments continue to be made, raising issues that I think the words of Gen VP Malik, former Chief of Army staff, sum up most eloquently:

Link
[quote][i]
Technical claims of Pokharan-2 have been challenged by many scientists. One is not worried about the challenges made in the Western media. But many of our own scientists have created doubts in the mind of the public and, more importantly, of the end users — the armed forces. This doubt is compounded by the fact that our DRDO scientists are known for tall claims and over-optimistic public statements.

Our long-term policy on fissile weapons and thermo-nuclear weapons is not yet clear. What progress has been made in this regard? Do we have adequate material for warheads to be made in future?

How long are we going to take to develop the triad i.e. land, air and naval-based launch systems? The time taken to develop the Agni missile system shows that the current progress is far too slow. Why is the government unable to push this programme? Is it a political or technological problem?

The nuclear doctrine calls for full integration of the doctrines concerning the armed forces, foreign policy, atomic energy, the DRDO and several other elements. How far have we been able to achieve this?

Do our political leaders have the idea and the will to employ nuclear weapons in times of crisis? The lack of consensus on serious strategic issues like the Indo-US nuclear deal or our policy towards China does not inspire confidence.

We now have the Strategic Forces Command, an inter-Services entity for strategic command and control. Have the Services developed a joint operational doctrine on the employment of nuclear weapons? Have we been able to interface the nuclear capability with conventional capability and plans in military strategy and force structuring?

Nuclear doctrine calls for multiple agencies involved with storage, movements and assembly of devices. Has the Strategic Forces Command been able to interlock with the other agencies involved in this effort? Will these agencies be able to achieve these tasks in different contingencies in the “shortest possible timeframeâ€

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Postby p_saggu » 22 May 2008 08:48

I would like to raise a few points here:
1. The mere fact that Gen. V P Malik has raised these issues in the article that has been posted conveys that the issues raised STAND UNRESOLVED still.

2. Have the end users - the armed forces been involved in the development and final design of the weapons (were they taken along) or we will end up with another Arjun type situation where the armed forces say they rely only on air dropped weapons, not missile based ones.

3.There have always been unmentionable whispers among the people in the know wrt the tests, the devices that were tested and that which was not tested, with the general consensus that there simply is no alternative to further testing if India intends to be an advanced nuclear weapons power.

For those intelligent enough, it is not hard to deduce where we stand wrt our deterrence from the open source info available.

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Postby Karan Dixit » 22 May 2008 09:15

In my opinion, Malik is not doubting that India has a robust nuclear program. What he is saying is take military into confidence. That will increase the credibility of nuclear deterrence or else it will be seen as irresponsible posturing by international community. After all, fighting is what armed forces do for living. So, who is better suited to handle the nukes? Civilian organizations or military organizations?

My humble answer is - military organizations.

I have no reason to doubt India's weapons program. I have not seen anything in western or Indian media that would instill doubt in my mind.

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Postby Neshant » 22 May 2008 11:38

As I recall shortly after the test, some scientists said they would have to conduct a soil analysis to determine if the H-bomb was a success.

I don't know why one would have to do a soil analysis (looking for certain isotopes perhaps), but it cast a great deal of doubt about the success of the test.

The US govt which sent a U2 spy plane from Bahrain to take air samples looking for tell tale signs of an H-bomb test probably has a better idea of whether it was a success or failure.

In any case, no country can build a nuclear deterrent on the basis of one questionable H bomb tests where scientists themselves are confused about the outcome.

One theory I've heard is that they were experimenting with the use of (much weaker yielding) thorium in a nuclear weapon since India has a lot of it. If so, it would be the first known test of thorium rather than uranium/plutonium in a n-bomb design.

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Re: Casting doubt on Indian nuclear weapon designs and yield

Postby Arun_S » 22 May 2008 13:55

shiv wrote:One warhead was claimed to be one boosted fission warhead of 45 kilotons

Don't think I have much stamina or time to participate in this thread except to ask you to enlighten us on what is the basis for the above statement? And how is that congruent with top dog scientists clearly saying in press interview (reported by almost papers after the aftermath of Pok-II) that what was tested was a 2 stage thermonuclear device? They were at pains to dispel foreign analysts speculating/doubting in light of non-megatonne yield that India must have tested a boosted fission and now boasting & trying to pass on that as thermonuclear explosion.

AFAIK there was no official statement that India tested boosted fission warhead, much less boosted fission warhead of 45 kt yield.

Within the constrain of item A) outlined for this thread and with contradictory statements on record by the scientists, I wish this thread luck with discussing any serious real technical issue w.r.t Indian nuclear program/capability except in very abstract terms unconnected with reality. A classic case of a bind men arguing on the real elephant in the room, based on their limited ESP, knowledge and effort.

My first and perhaps last post on this thread avatar

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Postby shiv » 22 May 2008 15:17

The information I posted above is from memory - but my memory dates to detailed notes I took when R Chidambaram gave a talk in IISc in 2002.

My note exists in the archives of BR, but let me cross post it here:
http://forums.bharat-rakshak.com/viewto ... 98&start=0
All in all, a gripping talk. Any technical errors probably mine.

First, the talk was organised by an informal group called "Prasthutha" in the IISc. This group was started by a group of concerned individuals at the IISc who were stung by the criticism of India and Indian technology that was aired at a meeting in the IISc shortly after Pok-2, and decided to form a group to counter this.

Chidambaram started by talking about where "power" derives from in the modern day spoke of two key areas in which domination is likely to be exercised in the future - namely Intellectual Property Rights and Technology Denial regimes. Technology is the currency of power.

He then put up a slide of Venn diagram of Indian nuclear technology vs other nations (a picture that has been linked before from BR) where Indian nuclear tech is an island not interlinked to the US and USSR unlike the tech of China/UK/France/Israel/SA and Packeeland.

Pre 1974, people used to talk of the peaceful uses of nuclear explosions. It was said that fission bombs would be good for oil exploration, and fusion for digging/excavation. That is because fusion reactions can be tailored to produce only neutrons and little fallout that can get into water supply (see footnote 1) But ALL talk of peaceful use of nuclear weapons ended abruptly after India's 1974 test. It appeared that all the "peaceful uses" tests were cover for military testing.

Chidambaram stressed that the 1974 test was of a design that was "not weaponised". He said it (and it has come from the proverbial horse's mouth here, despite what Carey Sublette may allege) that the Pokhran 1 yield was 12-13 kT. He then put up a slide showing a quote from a 1994 paper by Wallace estimating the yield at 10-15 kT, and showing a quote from a Wallace paper of 1998 saying that Pokhran 1 was 5 kT.

The 1998 tests were for weapons and all the tests were designed with devices that had all the necessary bells and whistles for delivery for military use.

One slide showed the photos of the 5 sites in Pokhran after the 1998 tests.

They were, as reported:

Test 1: A two stage thermonuclear bomb (H-bomb) with a primary trigger that used a fusion boosted fission reaction using an "X-ray radiation implosion" and a secondary fusion device. The total yield was calibrated to 45 kT. Quoting Chidambaram's words (I took notes) "The same design can go to 200 kT without any problem"

Why 45 kT? Khetolai village is 5 km away.

Test 2: 15 kT: This was essentially the same as the 1974 device, but this time all the necessary size and other requirements for use as a weapon were incorporated in the design. This shaft was 1 km away.

Tests 3: 0.2 kT - this shaft was a few km away.

Tests 4 and 5: May 13 1998: 0.5 and 0.3 kT.

Why simultaneous tests? Because adjacent shafts and equipment would be damaged by even a single big test.

He gave some technical details about the depth of the tests conducted, crater formation and seismic estimates. If you place a nuke deep enough, you will see nothing on the surface. If it is too shallow, there will be a huge crater and radiation will leak. If it is just right, there will be a small subsidence crater and no leak. (see footnotes 2 and 3)

About the seismic signatures, he said what has been said often on this forum. The Pokhran site has not been calibrated by seismologists. He also said that seismologists have been assuming Pokhran rock to be like Kazakh rock, but it is more like the rock in Nevada, and this has been shown in a Current Science paper by Sikka of Oct 25 2002. He showed a slide of the Gauribidanur seismic signatures of 1974 and 1998, which showed mb values of 4.9 and 5.4 respectively.

All the test sites were carefully monitored for a radioactive leak and there was none. In fact, in response to a question, he pointed out that Pokhran village water supply has been annually monitored for radioactivity since 1974, and another prof (name?) in the audience said that anyone is welcome to take the trouble of checking water samples from Pokhran villages for radioactivity if they have any doubt.

All yields were estimated by various methods, apart from accelerometers and close in instruments, the cavities were sampled to reveal the particular radioactive products that had been formed. Apparently there are telltale signs here - because in a fusion bomb the amount of neutrons released has effects on the local rock and caused certain compounds to be formed depending of the energy and dosage of radiation. The levels of those compounds eg 54Mn tell tales about the reaction and Dr RC stressed confidently and repeatedly that all the calculations and predictions for yield were validated and the yields were as reported AND as predicted.

Dr Chidambaram repeated time and again that computer simulation and the level of development in physics had made it easier to simulate and predict a lot of stuff and leave less to chance. He said that in the last 10-20 years there has been a vast increase in the amount of knowledge regarding "equations of state" of elements. In the 50s and 60s these were not known, and computers were very slow. If it took 3 months to do a particular calculation, it was easier to conduct a test, check the results and then tweak the computer to fit the results. He showed a very interesting graph of how the number of tests conducted by the US dropped with each jump in computer number crunching ability. RC said that a LOT of the work was done on computer and a lot of the computer simulations were verified against available data even before the tests. The overall impression I got was that fast computers have played a major role in the success of the tests.

RC dwelt at some length on what he called the "chotus" - the "little ones" among the tests. Why 0.2 kT? He went into some technical detail here (see footnote 4) and said that after the CTBT came into effect France and China were not confident of computer simulation of devices less than 0.2 kT, (unlike the US), so they called for a modification in the CTBT requirements so that tests uoto 0.2 kT could be done, For that technical reason it was thought necessary to test a 0.2 kiloton device in Pokhran.

RC ended the talk by saying that he jokes with his American friends - your bombs are 1992 vintage - when you stopped testing, ours are 1998 vintage. He also said that a great deal of work has been done (in India) since 1998, but did not specify.

Footnotes:

1)Fusion produces one neutron for 14 MEV release of energy, while fission produces relatively fewer - 3-4 neutrons for 200 MEV release of energy. Fiss1on is energy intensive and fusion neutron intensive.

2)To get the right depth to test at a Chidambaram spoke of "scaling". If you want no crater, you have to put your device as deep as 150 meters per kT of yield. He quoted the formula Y1=xY, where Y is the yield and he said that if you assume x=1=USA dry hard rock, then the value for Pokhran is 0.5. It happens that Pokhran is a good place to test nukes.

3)Chidambaram said that if 1 Kg of Pu is fully used up in a nuke - the yield will be 16KT (less if less is used up, of course). If 1 Kg of Deuterium is used up fully - you get a yield of 80kT, and if 1 kg of Lithium Deuteride is fully used up in a fusion bomb the yield will be 50 kT.

4)In fissile material k=population of neutrons in present generation/population of neutrons in the previous generation. In a runaway chain reaction - eg a nuclear bomb k>1. In a steady state nuclear reaction k=1, and in storage k<1.

CTBT allowed for tests as long as k<1. That was fine for the US as it was actually able to do undetectable subkiloton tests or simulate on computer. France and China objected and wanted th elimit raised to 0.2 kT below which they had not developed the ability to validate at the time of signing.

5)The high point of my day came as soon as RC entered the room. I was the only chap in the front row and he sat next to me. I introduced myself and mentioned BR. He said "Oh yes, I used to look at the site about 2 years ago - maybe I ought to look at it again. I asked him about Wallace and his fudging and he remembered and mentioned my name during his talk when he showed his slide on Wallace's changing statements.

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Postby sauravjha » 22 May 2008 15:24

A two stage thermonuclear bomb (H-bomb) with a primary trigger that used a fusion boosted fission reaction using an "X-ray radiation implosion" and a secondary fusion device. The total yield was calibrated to 45 kT. Quoting Chidambaram's words (I took notes) "The same design can go to 200 kT without any problem"


yeah but that reinforces what Arun-S is saying . there was no media report that a boosted fission device of 45kt yield was tested. only that a 2-stage thermo nuke with reduced yield of 45 kt was tested.

Shakti-III was the only so called pure boosted fission device that was tested.
the thermo nuke had a boosted fission primary.

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Postby Arun_S » 22 May 2008 15:31

I read your notes few times but I did not see anything that can be remotely construed to equate that with the opening statement that "One warhead was claimed to be one boosted fission warhead of 45 kilotons",

you may want to change that opening statement that is otherwise misleading to untrained eyes, and presumptuously change the basis of the debate.
Last edited by Arun_S on 22 May 2008 15:33, edited 1 time in total.

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Postby shiv » 22 May 2008 15:32

Throwing some more light on the info I noted at the talk - note that R.Chidambaram said "fusion boosted fission" device.

In an interview to FAS he said:

http://www.fas.org/news/india/1998/05/980500-conf.htm
Q: How near is the thermonuclear device to a hydrogen bomb? What was the material used for the fission trigger?
A: (RC) - The hydrogen bomb is the popular term. In a hydrogen bomb there is a fission trigger and separately there is also thermonuclear material which requires appropriate configuring. It is therefore a two-stage device. The secondary stage provides the major yield. The range can go quite high but we were limited in the total yield by the damage it may cause to habitations nearby. We are not revealing the materials used.
<snip>
Q: Can you confirm that it is a thermonuclear and not a boosted fission test?
A: (RC) - As I said earlier, a thermonuclear weapon has two stages, a fission trigger and a secondary stage. A boosted fission device is not a hydrogen bomb. A hydrogen bomb must be two-part.


WIKIPEDIA says:

http://en.wikipedia.org/wiki/Nuclear_weapon_design
Pure fission weapons were the first nuclear weapons built and the only type ever used in warfare. The active material is fissile uranium (U-235) or plutonium (Pu-239), explosively assembled into a chain-reacting critical mass by one of two methods:
Gun assembly, in which one piece of fissile uranium is fired down a gun barrel to a fissile uranium target at the end of the barrel (plutonium can use this design, but it has proven to be wildly impractical), or
Implosion, in which a fissile mass of either material (U-235, Pu-239, or a combination) is surrounded by high explosives which compress it, turning the sub-critical mass into a critical mass.

Fusion-boosted fission weapons improve on the implosion design. The high temperature and pressure environment at the center of an exploding fission weapon compresses and heats a mixture of tritium and deuterium gas (heavy isotopes of hydrogen). The hydrogen fuses to form helium and free neutrons. The energy release from fusion reactions is relatively negligible, but each neutron starts a new fission chain reaction, greatly reducing the amount of fissile material that would otherwise be wasted. Boosting can more than double the weapon's fission energy release.

Two-stage thermonuclear weapons are essentially a daisy chain of fusion-boosted fission weapons, with only two daisies, or stages, in the chain. The second stage, called the "secondary," is imploded by x-ray energy from the first stage, called the "primary." This radiation implosion is much more effective than the high-explosive implosion of the primary. Consequently, the secondary can be many times more powerful than the primary, without being bigger. The secondary could be designed to maximize fusion energy release, but in most designs fusion is employed only to drive or enhance fission, as it is in the primary. More stages could be added, but the result would be a multi-megaton weapon too powerful to be useful. (The United States briefly deployed a three-stage 25-megaton bomb, the B41, starting in 1961. Also in 1961, the Soviet Union tested, but did not deploy, a three-stage 50-megaton device, Tsar Bomba.)

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Postby sauravjha » 22 May 2008 15:38

shiv ,

A two stage thermo nuke with a boosted primary is very different from a boosted fission warhead . there is no point in arguing about it. A 2 stage device will obviously have a primary. A person who does not read the notes that you have posted subsequently will get the impression that you are talking about a boosted fission device only.
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Postby shiv » 22 May 2008 15:41

sauravjha wrote:shiv ,

A two stage thermo nuke with a boosted primary is very different from a boosted fission warhead , that your post seems to imply. there is no point in arguing about it. A 2 stage device will obviously have a primary. A person who does not read the notes that you have posted subsequently will get the impression that you are talking about a boosted fission device only.


In fact I am the ignorant party here and would be glad to understand the differences. But I am certain about my 2002 post made by detailed notes I took.

I am currently googling for whatever info is available as public source

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Postby sauravjha » 22 May 2008 15:46

hey your notes are fine , they clearly say two stage thermo nuke.

just for ready reference:

http://www.southasiaanalysis.org/papers5/paper451.html

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Postby Dileep » 22 May 2008 15:53

The original phrase used by the PM was "a boosted fission device, a thermonuclear device and a low yield device". I had no idea what they are anyway.

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Postby shiv » 22 May 2008 15:55

The information I am getting from Uncle Google is confusing - which makes it intriguing

http://www.ccnr.org/india_press.html
According to reports, India exploded one or more simple fusion-boosted fission weapons, and a two-stage thermonuclear weapon. In both cases, the externally-supplied tritium was apparently extracted from the heavy water moderator of CANDU-type reactors using a breakthrough technology developed by India which has drastically reduced the cost of producing weapons-grade tritium.


http://www.bharat-rakshak.com/MONITOR/ISSUE3-1/sbm.html
The issue of the thermonuclear test of 1998 has been discussed to exhaustion by many people - some 'experts', others who actually know what they are writing about. At worst, the test achieved roughly a 10-33% thermonuclear burn. The 45kT device used a 15kT boosted fission trigger and a 30kT fusion stage. It appears that the device achieved around 8-10kT of the 30kT fusion stage. If the primary stage was 20kT boosted-fission stage - as Dr. P.K. Iyengar claims - then 5kT instead of 25kT was achieved in the fusion stage.


http://www.hinduonnet.com/fline/fl1512/15120260.htm


http://query.nytimes.com/gst/fullpage.h ... A96E958260
Hydrogen bombs come in two types. In the first, American specialists said today, scientists fill the core of a small atom bomb with hydrogen fuel, a trick that can boost its power 10 times or more.
But making a true hydrogen bomb hundreds or even thousands of times more powerful requires a more complex method. In this second variety, the secret is to harness the radiation from an exploding atomic bomb and use that to compress and heat a packet of hydrogen fuel situated not internally, but nearby.
It was such a weapon that the Indian scientists described at their news conference. Drs. Chidambaram and Kalam repeatedly emphasized that the weapon they detonated involved a ''fission trigger,'' meaning a small atom bomb that set off the main blast, and not the other type of thermonuclear weapon, which they described as a ''boosted fission'' device.


http://www.indianexpress.com/res/web/pI ... 04016.html
Chidambaram said the thermonuclear bomb tested consisted of a fusion-fission-fusion system of which a boosted fission device was a part without having to test it separately. He revealed that most nuclear weapon powers had gone through the traditional path of separately testing a boosted fission device.

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Postby Sanku » 22 May 2008 16:01

Umm cant see what the confusion is really;

One type was clearly boosted fission
One type was two-stage thermonuclear (hydrogen) warhead

RC was at great pains to explain that indeed two stage device was tested and not merely the boosted one.

One low yield device was also tested.

All reports say the same in different languages; there is no contradiction between them.

What exactly is the problem?

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Postby sauravjha » 22 May 2008 16:02

Now which is the low yield device ?- Shakti III presumably , because it is sub-kiloton, because if the former PM was referring to the 14-15 kT device aka Shakti II , that was just a Pokhran type pure fission device even according to Shiv's notes and 14-15 Kt is hardly low yield for such a device.


But the fact is it was actually Shakti III which was touted as simply the primary stage of a boosted fission device. which is why the yield remained below a kiloton. So in essence , the sub-kiloton device is the boosted fission device that AB mentioned.


which means that the 14-15 KT device is being described as low yield. get the math?

remember a boosted fission device may use RGPu for the boost.
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Postby shiv » 22 May 2008 16:07

Throwing oil on fire - why is it that people want to cast doubt on the yield of one particular test on May 11?

I mean - after all those two test on May 13 dubbed as "sub-kiloton tests" did not show up at all on seismographs. Maybe thy were huge thermonuclear devices that failed to explode.

Any takers?

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Postby Sanku » 22 May 2008 16:10

sauravjha wrote:get the math?


Was that for me? No I don't get it in fact I am now truly confused too.

Can you make a table and say which is which and what kiloton?

Also I thought the confusion was around the use of 45Kt boosted fission device being actually a thermonuclear device. I am very confused about
1) Which device was what as Shivs notes.
2) What are people confused about in the reports.

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Postby sauravjha » 22 May 2008 16:11

Throwing oil on fire - why is it that people want to cast doubt on the yield of one particular test on May 11?

I mean - after all those two test on May 13 dubbed as "sub-kiloton tests" did not show up at all on seismographs. Maybe thy were huge thermonuclear devices that failed to explode.

Any takers?


Because of the language and the heterogeneity of the devices involved . it's easy to confuse people if you test and announce.

On so and so date , we did.

1. 2 stage thermonuclear device with first stage boosted fission primary.
2. then we did pure fission type device with refinements
3. then we tested a boosted fission device where we only tested the primary.

lay people, will be conphused, only , no?

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Postby sauravjha » 22 May 2008 16:15

In the above cases:

1. 45 Kt thermonuke ( the device in Shiv's notes)
2. Pokhran type pure fission- 14-15 kt
3. primary stage only of boosted fission device- 0.3-0.5 Kt (yield is low because second stage has not been used)

So which is the low yield device that AB is referring to : no.2 or no.3. Because 14-15 kt is not really low yield is it? it is relatively low yield if you are comparing yourself to a megaton thermonuke.

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Postby Sanku » 22 May 2008 16:23

Ok I see; so the only confirmation of the boosted fission design working in entirety (since one had only primary) was one on the thermonuclear device? Which is a can of worms in what yield came from what part.

Shiv is right; on that logic I now suspect the boosted fission device working properly as well.

GoI should test a stand alone but complete boosted fission warhead too if my understanding is right.

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Postby sauravjha » 22 May 2008 16:31

Yes a full test of the boosted fission device , that is , no.3 on the above list has not been done at all.

Also the yield of no.1 which is a two stage thermonuke has been deliberately limited. thus you can see why some people are clamouring for a test that will give full validation.

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Postby Sanjay » 22 May 2008 16:45

The argument being advanced by some - rightly or wrongly is irrelevant unless we can debate it and thrash it out - is that the S-1 device purportedly of 45KT may very well have achieved 45KT but was intended to be really of 200KT yield and hence the burial depth of 200m or so.

That aspect has not been dealt with adequately.

Why bury to such a depth ? Would a 200KT detonation really have wrecked the nearby village ? IIRC, there was some damage there even after the May 11 tests.

Re: S-3, is it not conceivable that this was a boosted-fission primary done with reactor grade plutonium ?

What nobody seems to be querying is that the fusion-boosted-fission primary of S-1 worked to whatever full yield was desired of that primary stage (I have read estimates from 12KT to 25KT).

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Postby Singha » 22 May 2008 16:51

atleast one blast for #1 upto 250 KT full yield and one for #3 with second stage seems to be logically needed.

afterall, if we are going to make the 250Kt warhead as the cornerstone of
our deterrence, it should be tested for sure!!

its time to break the Moratorium...Unkil is totally powerless at this stage,
a fight with India is the last thing they need with peak oil, ME, recession,
and PRC-Russia working them over. there will be some noises made and
thats all.

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Postby sauravjha » 22 May 2008 16:52

Re: S-3, is it not conceivable that this was a boosted-fission primary done with reactor grade plutonium



that's precisely what it has been touted as .
so basically your nuclear deterrent is based on

a. A two stage thermonuke device with a boosted fission primary , yield only 45 KT (shakti-I)
b. A boosted fission device whose only primary you have tested. Shakt-III
c. two experimental low yield weapons one of them using U-233 . totally experimental. Anything below one kiloton in this case is experimental onlee. (Shakti IV and V)

So your "nuclear break out" statement is made up of experimental devices and lower yields. all done so that some poor villagers can continue with their livelihoods.

All this leaves only the Pokhran type device ( Shakti -II) , which means that the centerpiece of our deterrent is a 14-15 KT Atom bomb tested only twice. and that to in different avatars.

Great , nuclear warfare anyone?

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Postby saumitra_j » 22 May 2008 17:45

Sanjay wrote:Why bury to such a depth ? Would a 200KT detonation really have wrecked the nearby village ? IIRC, there was some damage there even after the May 11 tests.


Sanjay ji, per Dr R Chidambaram's article here, the 200 m depth was also to do with radioactive contamination of sites. To quote from the article:
The depth of each shaft was so chosen that, after the tests, there was no radioactive contamination at the test sites. To establish this, extensive radioactivity monitoring (both ground based and air-borne) surveys were carried out before and immediately after the events and at periodic intervals thereafter. Again, as in the May 1974 test, reconnoitering health physics teams went up to surface ground zeros soon after the detonations and, after necessary checks, pronounced the areas as radiation free, for recovery of instruments for experiments fielded nearby


Also per this article - the thermonuclear device (as well as others)was a warhead and not exactly a test device.

cheers,

Saumitra
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Postby SaiK » 22 May 2008 17:46

I guess as suggested by previous threads, we have to see what kind of testing facilities we have built and are building for lab and subcriticals, that should gives us a ballpark figure to trust the statements made by babooze and anti-neo-nukeperts.

next time we test, it should be 200 feet beneath ocean surface somewhere away from tectonic plate edges [to avoid tsunamis].

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Postby prashanth » 22 May 2008 18:31

shiv wrote:Throwing oil on fire - why is it that people want to cast doubt on the yield of one particular test on May 11?

I mean - after all those two test on May 13 dubbed as "sub-kiloton tests" did not show up at all on seismographs. Maybe thy were huge thermonuclear devices that failed to explode.

Any takers?


Dr.Shiv,

Let me come to the point. If what you say is true, then you have to agree that the 45kt bomb was indeed a success. If it were a failure, then they would not have done the so called subkiloton tests which you say were flopped thermonuclear tests, without confidence. No point in conductiong more than one test of the same design if the first one is a failure.
Further they could not have ventured to test 3 separate TN weapon design in one season of nuclear tests, if you want to assume that the last two tests were TN weapons of different designs.

Friends,please comment on this.

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Postby Sanjay » 22 May 2008 19:10

I appreciate everything Dr Chidambaram said re shaft depth. However it still seems unusually deep.

Shiv, as an observation - you notice that there is a tendency to assume non-scalability of design tech among some ?

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India should retest

Postby VikramS » 22 May 2008 19:28

India should retest to dispel any doubts about her nuclear capability. India is sorrounded by hostile neighbours who do not recognize her territorial integrity or even its cultural/historical reasons to exist.

Currently the world's attention is focused on China and her ambitions. The West is afraid of China's emergence, whether it is the nuclear sub stations or the oil consumption. China has been rattling the sabre when it comes to India and, India has the legitimate right to test its nuclear option to clear up any doubts.

After the initial fall out from the NPAs and their ilks, a test is likely to reinforce India's emergence as an independent power. It is likely that countries in the South East Asia and Australia, will look up to India more, especially when there is a growing discomfort with China. Australia specifically needs to rethink its China bent and deal with India in similar terms.

A silver lining of the retest would be that the need for future retests will diminish, and the strategic cost of a self-imposed moratorium of testing will be minimal. That symbolic gesture can help trample NPA opposition to civilian energy cooperation.

The MMS government has been very accomodative of the TSP and ROP. They are receiving increasing flak from the mainstream. By testing again, they can help deflect the flak, while not alienating their ROP base.

The Asian region deserves a reasonable counterweight to communist China, and India is being offered the role on a platter. It is time that India recognizes that and acts accordingly.

But will MMS/UPA have the strategic vision to see that it is in their self-interest to test?

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Postby saumitra_j » 22 May 2008 19:47

Sanjay wrote:However it still seems unusually deep.

Sanjay ji - pardon my limited/non existent knowledge here but per wikipedia:
One figure used in determining how deeply the device should be buried is the scaled depth of burial, or -burst.[24] This figure is calculated as the burial depth in metres divided by the cube root of the yield in kilotons. It is estimated that, in order to ensure containment, this figure should be greater than 100.[24][26]
.
This can be found atthis link. In some analysis I had read a depth upward of 200m was quoted which seems probable as per this formula, the depth should be approximately 355m (100 * 45^(1/3) )!
Last edited by saumitra_j on 22 May 2008 20:02, edited 1 time in total.

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Postby saumitra_j » 22 May 2008 19:57

More details can be read from this paper.
In determining the depth of burial of nuclear devices, the usual law of energy scaling was used, in accordance with which the depth of the explosion is:
H ~ q1/3 (1)Where H is the depth and q is the energy of the explosion.

As a result, the first Soviet nuclear explosion was placed in tunnel V-1 at a scaled depth, H/q1/3, of 100 m/kt1/3, and the explosion in tunnel A-1 at 110m/kt1/3. The required conditions of containment were met under these conditions: specifically, the slow discharge of radioactive gases (Xe and Cs) into the atmosphere occurred several hours after the explosion and no transport of the primary radioactive products (Kr and Sr) beyond the test site boundaries

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Postby Sanjay » 22 May 2008 20:06

Saumitra, never apologize for a question or a comment to me. I am sometimes - heck most times - in the dark as much as anyone.

Your comments are 100% correct. But my concern is twofold - one soil/rock/ material density relative to the shaft depth and how the same is factored into such equations.

Work it backwards and you get a smaller yield for S-1 don't you ?

That said, I cannot ignore my source relating to excessive S-1 shaft depth.

Still though, you've made a very valid point.

Shiv, going back to the good old post POK-2 days, notice how nobody is talking about seismology and richter scale readings anymore ?

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Postby sauravjha » 22 May 2008 20:21

Saumitra, never apologize for a question or a comment to me. I am sometimes - heck most times - in the dark as much as anyone.

Your comments are 100% correct. But my concern is twofold - one soil/rock/ material density relative to the shaft depth and how the same is factored into such equations.

Work it backwards and you get a smaller yield for S-1 don't you ?

That said, I cannot ignore my source relating to excessive S-1 shaft depth.

Still though, you've made a very valid point
.

Shiv, going back to the good old post POK-2 days, notice how nobody is talking about seismology and richter scale readings anymore ?




1. of course the nature of the soil matters , that's why the equation is "proportional to" and not exactly equal to 1/3* energy.

2. the shaft depth is an enigma , isn't it? but it can always be explained away , for pure safety reasons of course...

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Postby p_saggu » 22 May 2008 20:35

Ok here is what I understand and the conclusions that I think are likely. Will require inputs / corrections from Arun_S and others please.

Shakti 1:
Claim: Two stage thermonuclear device.
Primary: Boosted Fission (Conventional fission system with hydrogen-deutrium inside the core for much higher yield); Status: Sucessfully gave the required yield / generated the required X-rays
Secondary: Mixture of lithium-deuteride / Hydrogen-deutride, Supposed to generate several hundred kiloton yield if complete fusion burn occurs;
Status: Underperforming secondary.
Cause: 1.Tamper failed to contain primary explosion long enough for required pressure to be generated?
2. Indian scientists failed to get the physics right. Unlikely, given the highly advanced level of nuclear physics in the country. (God help us all if this is the reason)
3. Engineering defects: ?Contaminants / Hitherto unknown factors / Poor assembly / materials used.
Conclusion: The device is believed to have under performed, Further testing is needed to verify the corrections made thus far.

Shakti 2
Claim: Fission device essentially similar to POK 1, but in a compact deliverable form
Status: Successful, yield and design parameters met.
Note: Here is the problem. Vajpayee clearly said "Fission device, Low yield device, Thermonuclear device" So the only boosted fission device tested was the one in the primary of the H-bomb.

Shakti 3
Claim: Low yield device.
Status: Unknown. Why test a low yield with the big daddies? Is it possible to get the signatures correctly with the big daddies going off in the neighborhood?
Conclusion: Did this device fail? What was it: the boosted fission / Device with the reactor grade plutonium / Device with Thorium?

Shakti 4 & 5
Claim: Low yield devices. Tested to acquire data for laboratory/computer based simulations.
Status: 1. Various firangs have said that it is too early for india to have tested low yield devices because they claim that India is yet not that technologically advanced as far as nuclear weapon physics is concerned - likely Psy-ops?
2. Again were these tests of devices using exotic material? Reactor grade plutonium/Thorium?
Conclusion: For purists the real issue is perhaps the secret that lies in these two tests (Not the H-bomb - A technology that is completely within the realm of Indian nuclear physics given the required political freedom)

Shakti 6
Claim: This device was not tested and was dug out of the ground after the test series and sent back to BARC, as there was no further need to test this design as it had already been verified.
Status:
1. Device was damaged?
2. The design was proven to be succesful therefore not re-tested.
3. The design was proven to have failed / underperformed. Therefore scarce materials not wasted and returned to the Lab for refinement.
Last edited by p_saggu on 22 May 2008 20:47, edited 2 times in total.

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Postby saumitra_j » 22 May 2008 20:41

Another article with analysis on the yield. I am posting some significant portions:
Yield estimation by analysis of cratering morphology is complicated in the case of the Shakti tests since the precise burial depth is not known as of this writing. Chengappa gives a depth of the 'White House' shaft for the Shakti I thermonuclear device as "over 200 meters" [Chengappa 2000; p. 427]. A notable feature of this shot is the lack of significant surface disturbance, unlike the fission shot in the 'Taj Mahal' shaft and Smiling Buddha.

Using the scaling law and constants for granite found here it can be determined that a 43 kt explosion at a depth of 200 m (the limiting case) in granite would produce a cavity with a radius of 42 - 44 m, and a chimney rising 176 - 300 m (i.e. reaching the surface) given that the chimney formation would be through porous non-granitic rock. Since the near surface of the Pokhran site is composed of loose material (sand and perhaps alluvium) that cannot cap chimney formation it seems unlikely that a 43 kt shot at 200 m could have avoided producing a subsidence crater. If the depth was 250 m the cavity would have been modestly smaller 40 - 42 m, and the chimney height similarly reduced. This makes capping of the subsidence chimney plausible, though a crater could still have occurred under favorable circumstances. The combination of geological factors, depth and yield reported from Indian sources thus is consistent with the observed effects. The observed effects are also consistent with lower yields of course. The absence of a subsidence crater however effectively rules out a burial depth of only 200 m however with the reported yield.

Radiochemical analysis is commonly said to be the most accurate means of yield determination. But this statement refers to an entirely different type of radiochemical analysis from what BARC performed in this study. The most accurate method is to determine the percentage of material fissioned by comparing the ratio of fission products to fissile material in a sample, thus giving the efficiency directly and with knowledge of the weapon design (how much fissile material is present) the yield can be easily calculated. Unfortunately publishing such data also discloses weapon design information normally kept secret. Attempting to directly calculate the total amount of fission is fraught with problems in accurately determining the three dimensional distribution of the material throughout the collapsed blast cavity.

Could it be that India has not released all the data regarding the depth of shafts to add to the confusion.?
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Postby sauravjha » 22 May 2008 20:42

Shakti 2
Claim: Fission device essentially similar to POK 1, but in a compact deliverable form
Status: Successful, yield and design parameters met.
Note: Here is the problem. Vajpayee clearly said "Fission device, Low yield device, Thermonuclear device" So the only boosted fission device tested was the one in the primary of the H-bomb.



No, shakti -3 was the boosted fission device with only the primary being tested. the primary in the 2 stage device was not the only boosted fission anything. I am saying this because, if it wasn't the case, I don't think the former PM would have explicitly mentioned in his speech , that there was a boosted fission device and a thermonuclear device .


Device with Thorium?



No point in having a device with Th-232 . the device has to be loaded with U-233 which is fissile . Loading a weapon with Th-232 what do you expect to do - breed U-233 ?
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Postby shiv » 22 May 2008 20:55

prashanth wrote:
shiv wrote:Throwing oil on fire - why is it that people want to cast doubt on the yield of one particular test on May 11?

I mean - after all those two test on May 13 dubbed as "sub-kiloton tests" did not show up at all on seismographs. Maybe thy were huge thermonuclear devices that failed to explode.

Any takers?


Dr.Shiv,

Let me come to the point. If what you say is true, then you have to agree that the 45kt bomb was indeed a success. If it were a failure, then they would not have done the so called subkiloton tests which you say were flopped thermonuclear tests, without confidence. No point in conductiong more than one test of the same design if the first one is a failure.
Further they could not have ventured to test 3 separate TN weapon design in one season of nuclear tests, if you want to assume that the last two tests were TN weapons of different designs.

Friends,please comment on this.


Prashanth - I am only sowing all sorts of thoughts - not that I believe them.

For example why on earth did they retrieve the 6th device?

After all - if they felt that there had been a significant failure, they could have tested the sixth.

The other point that occurs to me is that multimegaton bombs are being touted as the holy grail of deterrence. Note that an MIRV that peppers different points of a city with six 10 kiloton warheads (10,000 tons of TNT) can do serious damage by itself.

The other thing is that with nukes - why do you need "standardization"? I mean if a nuke can reasonably get you something between 10 kilotons and 25 kilotons and is reliable it is as deadly as one that reliably gets you 25 Kt every time. Who is going to celebrate the hitting of his city with a 10 Kt bomb by saying "nyahaha - that should have been 25 Kt!!"

The third thought that occurs to me is what I wrote on email to someone - i.e. If we were to look at a "limited" nuclear conflict in which India loses 3 cities and 15 million dead or injured and India retaliates with a strike that is equally devastating (with "mere" fission weapons) - the geopolitical and economic consequences would be no different from an exchange in which we used working thermonuclear weapons or working boosted fission weapons.

That is not to say that I oppose testing, but the opportunities to test are getting slimmer by the day. Testing an development have to take place by subterfuge - ie subkiloton testing and simulation.

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Postby sauravjha » 22 May 2008 21:02

The other point that occurs to me is that multimegaton bombs are being touted as the holy grail of deterrence. Note that an MIRV that peppers different points of a city with six 10 kiloton warheads (10,000 tons of TNT) can do serious damage by itself.


I don't think the military planner has this luxury . when you become a nuke state , you have to take into account all kinds of targets including nuke hardened structures. Your line of thinking is also fallacious because it assumes that all six warheads will reach the target , a luxury we certainly won't have in the near future.

there is no point in assuming that only soft civilian targets will be the focus during a nuclear war.
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Postby sauravjha » 22 May 2008 21:08

The other thing is that with nukes - why do you need "standardization"? I mean if a nuke can reasonably get you something between 10 kilotons and 25 kilotons and is reliable it is as deadly as one that reliably gets you 25 Kt every time. Who is going to celebrate the hitting of his city with a 10 Kt bomb by saying "nyahaha - that should have been 25 Kt!!"


same argument as above . this is not a gulli danda game . if you are not confident about what you have , you can't face down the enemy during a standoff. your bluff maybe called and the fact is your damage assessment will become a bitch in any war-gaming scenario , if you have umm "variable yield weapons".


he third thought that occurs to me is what I wrote on email to someone - i.e. If we were to look at a "limited" nuclear conflict in which India loses 3 cities and 15 million dead or injured and India retaliates with a strike that is equally devastating (with "mere" fission weapons) - the geopolitical and economic consequences would be no different from an exchange in which we used working thermonuclear weapons or working boosted fission weapons.

That is not to say that I oppose testing, but the opportunities to test are getting slimmer by the day. Testing an development have to take place by subterfuge - ie subkiloton testing and simulation.


there is no such thing as a limited nuclear conflict . once the genie is out of the bottle things get sad and bad real quick. the only time they didn't was the one time that nuclear weapons were used , against a non-nuclear enemy.


NB -Nuke hardened structures , house not just the enemy's war-fighting capability but his leadership and command structure as well. these need to be directly threatened for deterrence to truly prevail and five 10 KT warheads just don't cut it.
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