Pokhran II not fully successful: Scientist

pankajs · Post by **pankajs** » 03 Sep 2009 14:08

Hari Seldon wrote:Heck, for all we know, we might as well be having a sub-kt test every week since 1998 to refine and revise the simulation models.

Evaluation of Quantification of Margins and Uncertainties Methodology for Assessing and Certifying the Reliability of the Nuclear Stockpile (2008)

Page 45
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Finding 4-2. Any certifiable RRW weapons design will have to be “close” to the archival underground nuclear test base, while meeting reasonable criteria for adequate margin. The design and certification of new nuclear weapons that are sufficiently “close” to particular legacy designs could, in principle, be accomplished without nuclear tests, based on the existing nuclear test archive, on new experiments with no nuclear yield, and on modeling and

Page 46
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simulation tools supported by a QMU methodology more mature than at present.

For a certifiable RRW, the design labs will have to make the case that a new design is “close enough” to tested designs. The case would depend on establishing that the design is based on well-understood principles of nuclear warhead physics and engineering, that the design is related in key ways to designs that were successful in archived historical nuclear testing, and that any gaps between the knowledge of physics and engineering and the archival underground nuclear test base are bridged by experiments. Interpolation is highly preferable to extrapolation.

-----------------------------------
All reports will have bias based on the author. Take this for whatever it is worth. I haven't read the whole thing but it seems to be interesting and connected to the RRW program.

However in respect to the observation quoted from the previous post, here is the key line. Interpolation is highly preferable to extrapolation.

So, having 100's of sub-kt data points will not give us the confidence to design say 200 kt bum.

shiv · Post by **shiv** » 03 Sep 2009 14:15

I have some happy and not so happy thoughts.

I am certain India could not do sub kiloton tests before knowing the CTBT monitoring threshold. After May 13th 1998 it is possible that India got some wiggle room and may actually have managed to conduct some tests. Nobody will ever publicly confirm this so this is pure speculation.

My less happy thought is that MMS/weak India government may be preventing scientists from doing what they can in the eagerness to comply with CTBT. That may be why there is a scientist generated row now - with Sethna openly criticizing political interference.

Having said that let me point out a curious fact.

The May 13 tests are evidence that the CTBT monitoring stations are not foolproof. That means that the P5 wil continue to use masking and subkiloton testing in geographic areas where this is possible while the rest of the world has to eat CTBT crow.

I bet my ass that is India has done (or has had a chance to do) subkiloton testing - the US and China and Russia would have been merrily doing it all these years because they already have their national seismology mapped out in clear detail after dozens or hundreds of tests and wil know the areas where signals are getting masked and the areas where the geology is conducive to cheating. The US has even done tests with conventional explosive in hundreds of tons for this purpose.

Let me do use the same argument that has been used here in a different context. We will never know real sizzle till more tests are done, right? By the same token, the NPA will never know if people are cheating until a lot more test cheating is done. In other words the CTBT monitoring set up is a sham that is being supported by dubious seismological papers.

CTBT depends on robust monitoring. If that monitoring can be cheated - no CTBT. India has already cheated the monitoring system. How are we to know that other nations are not doing the same? How can any moron sign the CTBT under these circumstances?

One final world about geology/seismology and data sharing. If you do not know the geology of an area accurately you cannot estimate yield accurately. However if you do 3-4 tests in the area and accurately admit what the yield was - then it will be possible to compare all future tests at that site with the signatures of those 3-4 tests whose yields are known and it will be possible to know the yields of all tests in the area.

That is why SDREs will neither share the geology of the area, nor will they admit the real yields. No sharing-wearing business. Why do you think there are no Indian seismological papers about PoK I or II?

shiv · Post by **shiv** » 03 Sep 2009 14:22

pankajs wrote: However in respect to the observation quoted from the previous post, here is the key line. Interpolation is highly preferable to extrapolation.

So, having 100's of sub-kt data points will not give us the confidence to design say 200 kt bum.

At the same time, this fact is not a reason to avoid extrapolation by sub-kt tests if the opportunity exists. A lot of things can be validated IMO.

Neshant · Post by **Neshant** » 03 Sep 2009 14:27

I am certain a dataset of dozens of tests are required to build a simulator. It would have to include tests to verify the accuracy of the simulation itself.

One failed test is not going to produce any simulation.

Once again, hats off to the brave scientist who risked his career to save the country from blundering into a treaty by ignorant beaurocrats. He is a true patriot. Imagine the bravery it requires to put your entire career on the line. He deserves a medal of some sort.

The worst case scenario would have been signing the CTBT and then 2 years later hearing this admission.

amit · Post by **amit** » 03 Sep 2009 14:43

Neshant wrote:I am certain a dataset of dozens of tests are required to build a simulator. It would have to include tests to verify the accuracy of the simulation itself.

One failed test is not going to produce any simulation.

Once again, hats off to the brave scientist who risked his career to save the country from blundering into a treaty by ignorant beaurocrats. He is a true patriot. Imagine the bravery it requires to put your entire career on the line. He deserves a medal of some sort.

The worst case scenario would have been signing the CTBT and then 2 years later hearing this admission.

Nehant,

While I have no issues with the tenor of your post, one small but important correction. As far as I know KS has already retired.

Also are there any links, proofs etc that "ignorant bureaucrats" and their "equally ignorant political masters" are contemplating signing the CTBT?

Do note that even KS has said we should not sign CTBT till further tests. Nowhere has he or the other scientists who have dissented said we are on the verge of signing CTBT.

As I wrote in several previous posts, India's official stand on CTBT was articulated by one of these "ignornant bureaucrats" Shyam Saran in March. Since then, at least I've not seen, any articulation of the Govt's stand vis a vis CTBT (by an authorised person) which is at variance with what SS said at the Brookings Institute, save for speculation on BRF.

Now the point is if MMS goes to the US and does not sign the CTBT or give an assurance of signing in the immediate future, then who would be wearing the tag of "ignorant"?

Of course public memory is short, even on BRF.

shiv · Post by **shiv** » 03 Sep 2009 16:00

Folks here is something interesting that I found. As part of project "Plowshare" - the US conducted "Peaceful Nuclear Explosions". In a test called "Sedan" the US exploded a 104 kiloton test 200 meters underground to test earthmoving effects

Here - see what happens when 100 kt is exploded at 200 meters depth

http://oai.dtic.mil/oai/oai?verb=getRec ... =ADA436354

Abstract : The Sedan Experiment, part of the Atomic Energy Commission's Plowshare Program to develop peaceful uses for nuclear explosives, consisted of detonating a thermonuclear device of about 100 kiloton yield 635 feet underground in the alluvial flats at the northern part of the Nevada Test Site. The device was a relatively clean thermonuclear device in which fission contributed less than 30 per cent of the total yield. It was emplaced in a 36 inch diameter cased hole that was back filled with sand. Detonation occurred at 10 a.m. pacific daylight time on July 6, 1962. Some of the smaller earth particles formed a dust cloud which rose to a height of about 12,000 feet above the desert floor, somewhat higher than expected. The detonation formed a crater measuring about 1,200 feet across and 320 feet deep. About 7.5 million cubic yards of earth and rock were removed. The lip of the crater varied in height from about 20 to almost 100 feet. The predicted crater diameter was 1,200 to 1,400 feet and the depth from about 170 to 300 feet. As expected, most of the radioactivity produced by the explosion was trapped underground. A precise determination of the percentage of escaping radioactivity cannot be obtained from the available preliminary data, but this data shows that there was no major deviation from the prediction that about 95 per cent of the radioactivity would be trapped in the ground. The cloud, carrying dust and the small fraction of radioactivity which was not trapped underground or deposited close to the crater, drifted north at a speed of about 12 miles per hour. The heavier fallout was confined to within about two miles upwind and crosswind, and four miles downwind of ground zero, in line predictions.

A 200 meter deep hole will not contain a 150 or 200 kiloton blast when even 100 kt does what the video shows.

This should put some perspective on the sizzle ya fizzle debate. It can tell you how high S1 could have been, but not how low it actually was. It is unlikely to have been devised to contain a test even as large as 100 kt.

Sanku · Post by **Sanku** » 03 Sep 2009 16:14

But was the shaft 200 m deep?

shiv · Post by **shiv** » 03 Sep 2009 16:16

Sanku wrote:But was the shaft 200 m deep?

It was near enough, at 193 meters - or 635 feet as per the ref I have quoted above.

Sanku · Post by **Sanku** » 03 Sep 2009 16:26

shiv wrote:
Sanku wrote:But was the shaft 200 m deep?
It was near enough, at 193 meters - or 635 feet as per the ref I have quoted above.

I am sorry I missed it, which reference? And I suppose I was not clear as well, I was asking of the S1 shaft.

shiv · Post by **shiv** » 03 Sep 2009 16:29

Sanku wrote: I am sorry I missed it, which reference? And I suppose I was not clear as well, I was asking of the S1 shaft.

S1 shaft is quoted as being 200 meters in Raj Chengappa's "Weapons of Peace".

I have quoted and linked a text reference to the Sedan test with the video above.

JE Menon · Post by **JE Menon** » 03 Sep 2009 16:40

Something I have not understood. If the test was a failure, why did we claim that we conducted a test at all? We could simply have kept quiet to test another day, maybe a year or so later. While our scientists were in a hurry, they could not have been in such a hurry as to lie and lie repeatedly about it. At the most an earthquake would have been reported, and everybody would have gone home. Apparently, even the Americans were surprised by the test, but they damn sure wouldn't have been surprised by an earthquake.

Maybe it is a stupid question.

Sanku · Post by **Sanku** » 03 Sep 2009 16:41

shiv wrote:
Sanku wrote: I am sorry I missed it, which reference? And I suppose I was not clear as well, I was asking of the S1 shaft.
S1 shaft is quoted as being 200 meters in Raj Chengappa's "Weapons of Peace".

I have quoted and linked a text reference to the Sedan test with the video above.

Txs, on this basis and taking the 40-60% figure of 28 KT, a 50-60 KT would have been the desired yield.

However there are also reports of water sloshing around and the shaft being lower than the water table, how do these reconcile with the figure of 200 m?

Sanku · Post by **Sanku** » 03 Sep 2009 16:47

JE Menon wrote:Something I have not understood. If the test was a failure, why did we claim that we conducted a test at all?

My understanding is that the test would not have stayed a secret after it was conducted, there was an earthquake, the villagers were evacuated even if locally, there was some crater formation which would be a give away for the next satellite pass.

Overall too many give away to pretend nothing happened.

Also the tests themselves were not a failure, in the sense of total failure. By all accounts the FBF warhead did its job well. Even the TN device worked partially.

Given everything above + the need to establish India has a declared nuclear power and force Pakistan's hand, there was a good reason to go out and say things worked.

Yes, they could have pretended that the TN device was actually a FBF which worked, although I am not sure if that coverup was possible as well or not. I suppose there was a need to take the TN genie out of the bottle as well.

Tanaji · Post by **Tanaji** » 03 Sep 2009 16:58

shiv wrote:
Sanku wrote: I am sorry I missed it, which reference? And I suppose I was not clear as well, I was asking of the S1 shaft.
S1 shaft is quoted as being 200 meters in Raj Chengappa's "Weapons of Peace".

I have quoted and linked a text reference to the Sedan test with the video above.

Confused now, I dont have WOP with me. On page 46 you said:

N# it is technically easy to dig a hole down to 600 meters - well below the water table and then do a test. They could have done that but they did not. Possible reasons (in my view and entirely my opinion based on reading of open sources). Acc to Chengappa S1 shaft was "more than 200 meters" - but that, and the fact of wetness in the earth does not mean it is not above the water table. It could be on the upper reaches of a water table but still above. We just don't know

1) They did not want/have a mega bomb to test
2) They were deliberately trying to mask yields and test above the water table in sandy soil just to see what information the CTBT monitoring apparatus could get. That of course would automatically have forced a low yield test

Was it 200 m or more than 200 m? Or we don't know?

kenop · Post by **kenop** » 03 Sep 2009 17:10

JE Menon wrote:If the test was a failure, why did we claim that we conducted a test at all?

Test was to be conducted as according to intelligence available to GoI, Pakistan were ready to conduct one towards the end of May. It was done to be one up on them.
This was discussed a few pages back.

shiv · Post by **shiv** » 03 Sep 2009 17:12

Tanaji wrote:
Was it 200 m or more than 200 m? Or we don't know?

We can keep seacrhing and the figure may pop up from some ref or the other.

But while searching I found that Smiling Buddha in 1974 was at 107 meters and the may 13 tests were 50 meters (in a sand dune)

I am currently searching for refs regarding desired depth for a given yield. I have R Chidambaram's formula with me (for depth of shaft needed for planned yield) - but I am guessing that that his words are likely to be disbelieved so I am looking for independent sources.

shiv · Post by **shiv** » 03 Sep 2009 17:18

JE Menon wrote:Something I have not understood. If the test was a failure, why did we claim that we conducted a test at all? We could simply have kept quiet to test another day, maybe a year or so later. While our scientists were in a hurry, they could not have been in such a hurry as to lie and lie repeatedly about it. At the most an earthquake would have been reported, and everybody would have gone home. Apparently, even the Americans were surprised by the test, but they damn sure wouldn't have been surprised by an earthquake.

Maybe it is a stupid question.

No JEM - the May 11 test was too big and was sure to be detected.

I am certain that the May 13 tests were designed to validate subkiloton designs as well as to "test" the CTBT monitoring apparatus. Announcing the test was important because if the test was detected and India had no announced - India would be accused of cheating. By announcing and making NPA search their seismo records the SDRE's knew what signals had gone out. Only the SDRE's know exactly what was tested on May 13th, at what depth and in what sort of earth and at what time

Here is a related ref:

https://www.llnl.gov/str/Walter.html

On May 13, India announced two additional low-yield tests totaling 800 tons. The Livermore team examined data provided by the NIL station, but none showed any obvious seismic signal. Using the largest amplitude of the background earth noise around the time of the test as an upper bound for the signals from the event, the Livermore researchers determined that the event must have produced an mb of less than 2.8. The two tests were said to be conducted in a sand dune, which might poorly couple the explosive energy into seismic waves and thus reduce the strength of any recorded seismic signal. Adjusting for this geologic condition, says Walter, a signal should have been observable at NIL if the yield was 100 tons or more.
Walter says that the nuclear tests in India provided valuable data in a region with only a single previous nuclear test. This data will be used to help calibrate the CTBT monitoring network.
The data from the Indian tests will also improve scientists' understanding of the physical basis of the regional discriminants developed at Livermore. As a result of the tests, the discriminants may be applied with greater confidence to much lower yield explosions than the Indian tests and in South Asia and other regions where no nuclear test data are available to calibrate nearby monitoring stations.

JE Menon · Post by **JE Menon** » 03 Sep 2009 17:29

Guys, my point is that we could have lied about the tests more easily than the current set of supposed lies about the TN. If we just did not say we tested, what could have happened? Sure it would have been detected, but so what? If we did not confirm it, it would have been like the SA/Israeli one - which remains still a "suspected" test. I mean of course if the test did not work as per our expectations.

As for the Pak tests, pre-planned and so on - does not hold water, IMHO.

enqyoob · Post by **enqyoob** » 03 Sep 2009 17:31

OK, negi's 5-Page Memory Criterion has been met, I see. Some postors continue to beat the drum about what the "shaft was designed for".

They won't answer the basic question: What would have happened to the village (and, per shiv, to the venting/mushroom could/ radiation drift issues) if the yield had been any more than what it actually was?

If that cannot be answered, then the people arguing that the S1 test yield was less than its design yield, should please get off that argument and try something else. It is plain dishonest to continue to repeat something which you know you cannot defend, and which appears to have been conclusively proven to be wrong.

As far as I can see, some American tests that did get vented (Benetton?) were 278 meters deep, and blew out a mushroom cloud THREE AND A HALF MINUTES later, rising to over 10,000 feet and sending radiation clouds across to neighboring states. From a 10KT blast.

Another 100kT blast, from some large depth, blew a huge crater 1200 feet diameter. And sent plumes to 12,000 feet.

Do these facts convey nothing about the need to limit yield in the POK case? What is the point of debate if this is the nature of honesty in debating?

The ONLY "evidence" cited for the "fizzle" is that Dr. K.S. is quoted as saying something - which people INTERPRETED to mean that S1's actual design yield was at least 1/0.6 of what was actually achieved.

I say that any more yield would have caused unacceptable damage and venting, and it was already borderline, so no responsible scientist or engineer would have designed for any more yield than that.

The argument that Ground Zero Tourists saw no damage to homes several months later, has been conclusively debunked by articles and photos posted from that time.

There is no credible evidence of radioactivity actually killing anyone in the village, but there are some reports of children becoming very sick. Were they perhaps outdoors from the school as we see from the reports when the tests occurred?

The images show black dust/ whatever shooting out of the shaft. But this jet is only a few dozen feet high, it would probably have settled back down in the same area. Unlike the disaster images that we have been viewing from American tests.

But shiv's point, made repeatedly and very graphically, is that a larger yield than around 40 kT would indeed have resulted in disaster, proving the designer's claims.

The designers have revealed that they used available American test results with the geological data on that site, to validate their predictions and design.

Clearly one reason to do the tests in the area where they were done, is that this area was very thoroughly surveyed above and under, and they knew how to model the effects there.

Despite all this factual evidence, some postors continue to drumbeat about "fizzle". So I must conclude that their only interest here is to keep claiming that "INDIAN TESTS FIZZLED!!!" not to do an honest examination of the evidence.

Are you guys willing to change your position to agree that

1) ACTUAL YIELD > or = DESIGN YIELD for S1 (IOW, there was NO "fizzle" or Khetolai and all North India would have been "sizzled")
2) DESIGN YIELD was only 27 KT not 43 kT?

In this case we can move ahead and argue why the DESIGNERS limited it to 27 KT, and since their design proved accurate, does this not cause enough deterrent concern to the enemy that the designers can design well?

But if the above are not agreeable, then you are ignoring elementary facts and going around in circles beating on a hollow drum, plainly motivated by some politics or other stuff.

Mods, please step in and moderate by insisting on some elementary honesty and discipline in debate! Is this the C-SPAN forum where Pakis do this consistently, or the BRF? Thank you.

Raja Ram · Post by **Raja Ram** » 03 Sep 2009 17:40

N^3 there is still three more pages to go till we reach 50 for this thread. Which is 60% of the design yield onlee.

So please wait. Besides, there are now more nuances coming out from both camps. It is all entertaining. But nothing to beat the entertainment of Dileep's wonderful spy story.

It is very nice and even I can understand. Now that is real catering to the masses.

Sanku · Post by **Sanku** » 03 Sep 2009 17:42

JE Menon wrote:Guys, my point is that we could have lied about the tests more easily than the current set of supposed lies about the TN. .

Well the current set of supposed lies seem to have lived pretty well for 11 years. Not bad for a lie of this order I would say.

Would other easier lies would have also held water -- difficult to say apriori

JE Menon · Post by **JE Menon** » 03 Sep 2009 17:49

Yes, true, but the lie I'm suggesting would have been direct outward, not inward as the current set...
Plus, imagine the fun of a "non-nuclear Pakistan" after 9/11...

NRao · Post by **NRao** » 03 Sep 2009 17:49

there is still three more pages to go till we reach 50 for this thread. Which is 60% of the design yield onlee.

Which model says that?

Seriously, IMHO, India should test .............................. an open end test season that is.

Sanku · Post by **Sanku** » 03 Sep 2009 17:57

JE Menon wrote:Yes, true, but the lie I'm suggesting would have been direct outward, not inward as the current set...
Plus, imagine the fun of a "non-nuclear Pakistan" after 9/11...

Well I am sure that no one would have believed those lies, in the sense that it would be clear that we tested but are lying. I dont know what would be the impact of it. Pretty severe I would guess, in terms of sanctions etc.As it is things were tough. Plus it was a considered strategic doctrine of going explicitly nuclear.

My understanding is that the lie etc were part of a certain direction where a robust overt Nuclear stance was envisaged, including Arihants etc.

The lie should be seen in that context.

The problem now is that there is a feeling that there is a change in doctrine.

shiv · Post by **shiv** » 03 Sep 2009 17:57

Incidentally - there is a paper on BR that deals with cratering phenomenlogy and guesses the maximum yield possible in the S1 shaft.

http://www.bharat-rakshak.com/MONITOR/I ... crater.pdf

Thus the shaft S-1 was at most capable of a maximum of 100 kilotons.

The sedan event whose video I have linked earlier is mentioned - but there is no mention of the fact that it blew out - unless I missed it. Sedan vented when 104 kt was placed at 193 meters.

shiv · Post by **shiv** » 03 Sep 2009 18:06

JE Menon wrote:Guys, my point is that we could have lied about the tests more easily than the current set of supposed lies about the TN. If we just did not say we tested, what could have happened? Sure it would have been detected, but so what? If we did not confirm it, it would have been like the SA/Israeli one - which remains still a "suspected" test. I mean of course if the test did not work as per our expectations.

As for the Pak tests, pre-planned and so on - does not hold water, IMHO.

JEM - I am guessing that this is the political dimension to the test.

A lot of people (pre 1998) used to ask how the armed forces could be asked to fight China knowing that they had nukes and we did not. By not going public - those problems would have remained.

JMT

I believe that just because a lot of people are unhappy with the yield it is being assumed that the people who conducted the test were solely concerned with yield and were not bothered about other aspects - such as the possibility of future clandestine or overt testing, and the geopolitical signals and other technical issues like venting and damage on the ground.

Sanku · Post by **Sanku** » 03 Sep 2009 18:12

shiv wrote:Incidentally - there is a paper on BR that deals with cratering phenomenlogy and guesses the maximum yield possible in the S1 shaft.

http://www.bharat-rakshak.com/MONITOR/I ... crater.pdf

.

Finally, we address the question as to why BARC did not test a 100 kt device in shaft
S-1. The aim was to test a Agni con¯gured device with the sole opportunity provided to
the weapons design team. Thus to ¯t a package into the requisite dimensions probably
called for a device design with yield of about 45 kt. If there were no constraints, most
likely a test of 100 kilotons would have been likely with the attendant large crater..

No concern for Kehtolai !! No sir none at all, such cruel hard hearted fellows these are who wrote it.

enqyoob · Post by **enqyoob** » 03 Sep 2009 18:13

Shiv: By "Blowout" of Sedan I meant the picture of that You-Tube video that you have posted. I didn't play the video - need to get the sound hooked up on my computer b4 I do that, just in the hope of hearing a nuclear blast.

The picture shows two clear features:
a) Plume shooting up extremely fast
b) rolling "ground vortex" type structure spreading out, which means that the crater is developing, with the material being flung out.

One imagines that if one were standing a few dozen feet from that, one falls over - like standing around scratching one's golas a few feet from a Toyota sunroof lever when it "blows out".

enqyoob · Post by **enqyoob** » 03 Sep 2009 18:15

No concern for Kehtolai !! No sir none at all, such cruel hard hearted fellows these are who wrote it.

Isn't this flame bait? How smart does one have to be to figure out that this also fit the constraint to keep Khetolai alive, and decided the DEPTH at which to place the device?

Isn't this what has been driving this thread, and most threads where this postor "participates", in circles?

ShauryaT · Post by **ShauryaT** » 03 Sep 2009 18:16

A 200kt blast would have given a magnitude of 5.9. Although not exactly like a classical quake, do we know, what type of damage would occur at a certain distance of 5 KM? Also, what are the corresponding shaft depth levels to contain a 200 kt explosion underground?

enqyoob · Post by **enqyoob** » 03 Sep 2009 18:19

What damage would have occurred would certainly have been equivalent to some 4 or 5 times what actually happened (if the actual was 43kT), would it not? Plus there would be nonlinear effects. Also, beyond a certain threshold, most buildings would get so loose that gravity takes over and finishes the job.

Is there reason to be more optimistic than that, and if so why?

Most 5.9 earthquakes around the rest of India seem to cause very severe damage, why would Khetolai not suffer equally? Why would anyone design saying "Oh, 5.9! That is fine!", and if they were found to have done that, would you not call for them to be fired, prosecuted, hanged if there were fatalities?

shiv · Post by **shiv** » 03 Sep 2009 18:21

narayanan wrote:Shiv: By "Blowout" of Sedan I meant the picture of that You-Tube video that you have posted. I didn't play the video - need to get the sound hooked up on my computer b4 I do that, just in the hope of hearing a nuclear blast.

The picture shows two clear features:
a) Plume shooting up extremely fast
b) rolling "ground vortex" type structure spreading out, which means that the crater is developing, with the material being flung out.

One imagines that if one were standing a few dozen feet from that, one falls over - like standing around scratching one's golas a few feet from a Toyota sunroof lever when it "blows out".

N3 - that mound rose 200 feet before venting. You need to get the audio as well - and this was 104 kt at 193 meters.

Sanku · Post by **Sanku** » 03 Sep 2009 18:30

ShauryaT wrote:A 200kt blast would have given a magnitude of 5.9. Although not exactly like a classical quake, do we know, what type of damage would occur at a certain distance of 5 KM? Also, what are the corresponding shaft depth levels to contain a 200 kt explosion underground?

Google says that earthquakes over 6 are considered to be significant and damage causing, also earthquakes which are sustained have far more damage causing ability than a small blip/pulse type quake.
http://www.answers.com/topic/richter-magnitude-scale

A scale of the magnitude of earthquakes, ranging from 0 to (in theory) 10. On this scale a value of 2 can just be felt as a tremor. Damage to buildings occurs for values of over 6, and the largest shock ever recorded had a magnitude of 8.9.

A nuclear explosion produces a pulse type quake dying away rapidly, no sustained vibrations. (Shiv linked a ref just above)

But BTW where did you get the 200 KT --> 5.9 figure? Finding a correlation between seismic activity and the yield produced is very tricky.

If the shaft was well designed a sufficient decoupling done, it is possible that various yields would not produce significantly large seismic activity than the previous one, i.e. no liner or higher (quadratic) correlation.

Kanson · Post by **Kanson** » 03 Sep 2009 18:41

JE Menon wrote:Something I have not understood. If the test was a failure, why did we claim that we conducted a test at all? We could simply have kept quiet to test another day, maybe a year or so later. While our scientists were in a hurry, they could not have been in such a hurry as to lie and lie repeatedly about it. At the most an earthquake would have been reported, and everybody would have gone home. Apparently, even the Americans were surprised by the test, but they damn sure wouldn't have been surprised by an earthquake.

Maybe it is a stupid question.

Infact, the first impression from the foreign experts is, POK-II is indeed an "earthquake".

Kanson · Post by **Kanson** » 03 Sep 2009 18:54

narayanan wrote:The ONLY "evidence" cited for the "fizzle" is that Dr. K.S. is quoted as saying something - which people INTERPRETED to mean that S1's actual design yield was at least 1/0.6 of what was actually achieved.

In iine of the discussion or shall i say the speculation, actually KS announcement is a short in the arm. He just claimed what NPAs were saying so far that 60% of the yield and confirmed the NPA findings are true. Imagine, every monitoring station has to be finetuned to the testing site, and this will affect the way, the further events are recorded. so if there .2 kt then probably it even wont show in the gram.

enqyoob · Post by **enqyoob** » 03 Sep 2009 18:56

N3 - that mound rose 200 feet before venting.

Ah! It was MounT Sedan!

Actually on the Shakthi videos that someone posted, the entire place seemed to rise to become a plateau some 20 or 30 feet high before it did a wave-like motion - I thought it was because the videocamera leaned over. Got to go look that and see if it can be played slow motion.

BTW, POK WAS probably just a minor quake. In fact, the first Indian hydrogen bomb explosion was the 1MT test at the Koynanagar Dam. Circa 1963?

(Now revealed from my Anonymous Source in the BARC who spoke on condition of anonymity because s(he) is not authorized to speak to the media and most certainly not to me. But s(he) did anyway, purely because I was only going to post it on BRF.)

Check the map to see where BARC is located. And where KoynaNagar is located.
I had NOOO idea!

shiv · Post by **shiv** » 03 Sep 2009 19:03

I announce with deep disappointment that I am not the first person to link the May 13 subkiloton tests with CTBT

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

Significance of the Sub-kiloton Tests Down to 0.2 kt

It is worth recalling that originally the U.S wanted to set the zero yield limit of CTBT at less than the device�s chemical explosive yield. A nuclear explosion in which a chain reaction has been initiated leaves a valuable fission product signature indicating success even at the lowest yield. That is why the U.S was later willing to take the above limit down to a few kilograms of TNT - equivalent. France and China demurred saying that they would prefer to set the threshold at 0.2 kt, which presumably was the precision limit of their calculation capability. The successful match between the design and achieved yields in the sub-kiloton tests down to 0.2 kt suggests that we have similar computer simulation capability. Incidentally, the finally agreed limit is true zero yield and the k = 1 line is the Lakshman Rekha of CTBT !

Threshold of Seismic Detection

This brings us to the question of seismic detectability of low yield tests. It is well known that the International Seismic Network, which is part of the International Monitoring System (IMS) for verifying CTBT compliance, has a threshold detection limit of 1 kt in hard rock 26, provided the test is non-evasive. The purpose of the IMS is detection and not yield calculation; the IMS relies on inspection visits for post-detection verification where considered necessary. Apart from concerns that have been expressed about evasion through decoupling by carrying out the test in an underground cavity, the nature of the emplacement medium is also important. The threshold limit for seismic detection is much higher in, say, a sand medium than in hard rock; the Pokhran geological medium comes somewhere in between. It is not surprising that the IMS did not detect our sub-kiloton tests of May 13, 1998.

Kanson · Post by **Kanson** » 03 Sep 2009 19:29

R. Chidambaram says:

In our tests the waveforms recorded have been confused because the detonations were simultaneous. In fact the American IDC has recorded our tests as an earthquake.

I think this will give new meaning to the discussion.

Kanson · Post by **Kanson** » 03 Sep 2009 19:35

From PKI:

The new revelation by Dr. Santhanam is that the actual total yield of the thermonuclear device (i.e. the boosted-fission part plus the fusion part) was only 60 per cent of the design value (of 50 kt), i.e., around 30 kt. This is also consistent with the yield values obtained from seismic data according to international sources.

and further

If we accept Dr. Santhanam’s number, coming as it does from one of the core members of the Pokhran-II tests, then the situation is even more serious. This suggests that the thermonuclear burn may have been marginal or may not even have occurred at all. This has very serious implications for our weaponisation programme and deterrence philosophy, and certainly invites much closer, detailed, technical scrutiny. Of course, none of these numbers are very accurate, but 10 kt more or less, in one direction or the other, will not materially alter these conclusions.

You see, now, why infact KS announcement is a shot in the arm. All Chanikiyan onlee..

ShauryaT · Post by **ShauryaT** » 03 Sep 2009 19:41

Sanku wrote:
But BTW where did you get the 200 KT --> 5.9 figure? Finding a correlation between seismic activity and the yield produced is very tricky.

If the shaft was well designed a sufficient decoupling done, it is possible that various yields would not produce significantly large seismic activity than the previous one, i.e. no liner or higher (quadratic) correlation.

Here I used the Dumont test May 19, 1966 as the reference for the above. The list there has crater size and shaft depth.