ramana wrote:The Hindu has contacted RC and has his inputs in the article by Siddharth Vardarajan.
Fizzle Claim refuted
The government on Thursday strongly refuted claims that the 1998 test of a thermonuclear device had been a failure, with Principal Scientific Adviser R. Chidambaram telling The Hindu that those questioning the tests yield had an obligation to back up their charge with scientific evidence.
He was responding to the recent statement by a former defence scientist, K. Santhanam, that “the yield in the thermonuclear device test was much lower than what was claimed.” Mr. Santhanam, who cited only unspecified “seismic measurements and expert opinion from world over,” went on to say that this was the reason India should not sign the Comprehensive Test Ban Treaty (CTBT).
The stated success of the second generation nuclear device tested on May 11, 1998, was questioned at the time by a number of Western seismologists who said the seismic signatures detected by them were at variance with the claimed yield of 45 kilotons. Although the controversy subsided somewhat once scientists from the Bhabha Atomic Research Centre — which designed the weapon — published their scientific evidence, it is likely to be reignited once again since Mr. Santhanam represented the Defence Research and Development Organisation (DRDO) team at the Pokhran-II tests and is the first member of that group to echo the arguments of those who say the thermonuclear device failed to work properly.
“If Mr. Santhanam has any scientific data to back up what he has claimed, I am sure BARC scientists would be more than happy to debate it,” said Dr. Chidambaram. “Without that, this kind of statement means nothing.”
In a 2000 article, The May 1998 Pokhran tests: Scientific aspects, republished in 2008 with some updated details, in a French journal, ‘Atoms for Peace,’ Dr. Chidambaram has argued that western seismologists who under-estimated the Pokhran yields did so because they did not take into account the geological structure at the Indian testing range. They also failed to appreciate that India’s weapons designers purposely went for lower yields because the shots had to be fired in existing shafts which could not be dug any deeper for fear of detection. Higher yields, then, would have caused damage to nearby villages and also led to the possible venting of radioactivity.
Dr. Chidambaram wrote that the thermonuclear device tested was “a two-stage device of advanced design, which had a fusion-boosted fission trigger as the first stage and a fusion secondary stage which was compressed by radiation implosion and ignited.” He said the argument that the secondary stage failed to perform is belied by post-shot radioactivity measurements on samples extracted from the test site which showed significant activity of sodium-22 and manganese-54, both by-products of a fusion reaction rather than pure fission. “From a study of this radioactivity and an estimate of the cavity radius, confirmed by drilling operations at positions away from ground zero, the total yield as well as the break-up of the fission and fusion yields could be calculated.” Based on this, he said, BARC scientists worked out a total yield of 50 +/- 10 kt for the thermonuclear device, which was consistent with both the design yield and seismic estimates.
As for the sub-kiloton tests of 0.3 and 0.2 kt of 13 May 1998, which the International Monitoring System for verifying CTBT compliance failed altogether to detect, he said “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” and so it was not surprising these two tests did not show up on the IMS.
“Let someone refute what we have written, then we can look at it,” said Dr. Chidamabaram, adding that he was yet to see a published critique of BARC’s scientific assessment by any laboratory-based scientist abroad.
A former senior official of the erstwhile Vajpayee government confirmed to The Hindu that there had been differences of opinion between BARC and DRDO scientists after the May 1998 tests, with the latter asserting that some of the weapons tests had not been successful. The internal debate was complicated by the fact that the DRDO experts, including Mr. Santhanam, were not privy to the actual weapon designs, which are highly classified. But the issue was resolved after a high-level meeting chaired by Brajesh Mishra, who was National Security Advisor at the time, in which the BARC experts established that DRDO had underestimated the true yields due to faulty seismic instrumentation. And the radioactivity analysis provided the clincher.
Since 1998, whatever his private reservations might have been, Mr. Santhanam appears to have stuck closely to the official line in his public pronouncements.
On the fifth anniversary of Pokhran-II, for example, he said in an article in Outlook that “the asymmetry with respect to China stands largely removed” thanks to the 1998 tests. Since China was a proven thermonuclear power at the time and India was not, it is hard to reconcile this optimistic assertion with the scientist’s current claim that the thermonuclear device India tested was “a fizzle.”
Similarly, in June 2007, Mr. Santhanam declared on CNN-IBN on a programme about the Indo-U.S. nuclear deal in which this correspondent was also a participant: “After May 1998, there was a clear declaration from India that we don’t have to conduct any more nuclear tests. India should not have any problem legalising this position. But this is subject to the condition that if the international security condition changes, then we should be allowed to test."
I think now there will be clamor to have the radio-chem analysis reviewed. And asking KS to produce data that BARC has is

.IOW its turning into ego match. And its par for the course for RC.
He did the same to PKI when Mehta saab made Mishraji arrange a face to face interview.
Mehra saab = Air Chief Marsahl S.K Mehra.
Mishraji = Brijesh Mishra.
And I was witness to this statement by ACM SK Mehra. He mentioned it to ME.
It is the same R Chidambrum of 1998 vintage, the shine of brash disdain for questioning his "superior birth" is not dulled a bit.

But this time people have seen the shame he tried so hard to hide. Dog's tail will always remain crooked.
ramana wrote:Meanwhile TOI reports.....
Kalam certifies Pokharan II, Santhanam stands his ground
Sachin Parashar, TNN 28 August 2009, 12:55am IST
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NEW DELHI: The claim of K Santhanan, former DRDO scientist who was in-charge of Pokharan II, that the thermonuclear device tested in 1998 was a fizzle detonated a full-scale row on Thursday, with former President A P J Abdul Kalam refuting the statement of his former colleague.
... . . . . However, an undeterred Santhanam told TOI on Thursday that the hydrogen bomb test was not more than 50-60% successful in terms of the yield it generated. He was supported by prominent nuclear scientists including P K Iyengar, a player in Pokhran I, who said Santhanam was only stating the truth, but Kalam sought to end the controversy by saying that the desired yield had been obtained.
The dispute is significant from the point of view of whether the country needs to conduct more tests - an option that has become expensive because of the nuclear cooperation deals with the US and other countries and which may disappear altogether if the country acquiesces to the growing pressure for Comprehensive Test Ban Treaty (CTBT).
Talking to TOI on Wednesday evening, Santhanam had said that the test was a fizzle because the actual yield was much lower than what was claimed. He told TOI on Thursday that the thermonuclear device test was only 50-60% successful. ... . . .
The crucial thing is the 20 -25 (45-20)kt of fusion. You need that much to ensure that an active tertiary will go off to give the desired all-up yield. RC and his cohort say Na-22 and what not was detected and ergo TN worked and full yield. PKI et al say yes, yes Na-22 etc was detected but that indicates only some fusion occured. And btw 50-60% of 45 kt design total is 22 - 27kt ie 2 to 7 kt fusion. Barely enough for the desired yield. So need to keep option to test.
So if some physics whiz wants to do the numbers and figure out how much a 2 -7 kt fusion gives and add that to the 20kt the total is the TN capability. I think the 7 kt will give about 50kt. and maybe more with innovation. So total of 20+50 = 70 kt. enough to take care of most fellows.
IIRC S1 yield was ~ 32kT;
Boosted Primary ~ 17 kT,
Fusion fuel ~ 3-4 kT
rest 10-12kT from spark plug and tertiary.
The test was a fully loaded test of 200 kt TN. Even if one takes at face value the 45 kT yield claim of Chidambrum, one can see what Chidambrum delivered.
BTW, Indian 100 kT FBF weapon using the Shakti series design would weigh ~ 350kg.
However if substantial modification/enhancement are made since then 150kT yield will weigh ~ 350 kg.
A thermo nuke OTOH will yield 200 kT, use lesser fissile fuel, weigh ~240 kg, and the SRDE missile in Arihant will throw it to useful distance, such that from its petrol area near Maldives it can take out Beijing.
However with the heavier FBF based warheads, one will need PSLV size missile that can carry enough oomph far enough.
And just four A3SL missile tube per Arihant will be useless, will need it to be increased to carry 16 missiles instead.
I say India should not test any more and instead use PSLV for deterrence and increase nuclear submarine fleet 5 times. Any takers??
Surely Chidambrum will see no problem with the above.