On Tuesday, the Atomic Energy Commission upheld the figure of 45 kilo tonne yield for the hydrogen bomb test of May 11. But the Karnal seismic array maintained by the ARC had come up with a figure of just 20-25 kilo tonne yield, which was in consonance with the figures that the DRDO instruments had recorded.
The facility at Karnal, in Harayana, which was specifically set up in the wake of the first Chinese nuclear test in October 1964, in association with the United States National Security Agency and the Central Intelligence Agency, have ultra-sophisticated instrumentation obtained from the US. “These are more sophisticated than anything that the Department of Atomic Energy has,” said a source. They are designed to track underground nuclear weapon tests and have their instruments in a deep vertical shaft dug deep into the ground, in contrast to the system mounted on the surface at the Department of Atomic Energy (DAE) facility in Gauribidanur in Karnataka.
The R&AW collated all its findings and after analyzing them, sent them to on to the government, presumably the Prime Minister’s Office. These findings, which were in agreement with those of the instruments set up by the DRDO on the test site, created consternation within the government.
There were several meetings held to reconcile the reports it had received from the DRDO, the Department of Atomic Energy and the ARC and finally, the then National Security Adviser Brajesh Mishra convened a meeting of the DAE, DRDO representatives along with the three armed forces chiefs sometime in October 1998. Since the two scientific organisations stuck to their positions, Mishra took a “voice vote” which decided that the DRDO was wrong and the DAE was right. An official familiar with the meeting noted that the ARC representative was not invited for the meeting.
“The decision to declare the hydrogen bomb a success was more of a political fatwa than a considered scientific-technical determination,” says Santhanam.
The NDA government’s response was an outcome of two interconnected factors. First, the admission of failure would have been politically damaging. Second, the tests had enraged the United States and New Delhi was simply not willing to prolong the process and it quickly declared a unilateral moratorium on further testing.
A view of the crater formed by the May 11 fission bomb test which yielded 25 kilotonnes. Note the distinct crater approximately 35m diameter
The picture of the shaft where the thermonuclear bomb was tested. This was supposed to be twice as powerful as the fission bomb, yet the shaft is intact
Another view of the thermonuclear test shaft area which shows no virtually no crater
Santhanam has since spelt out the reasons why he made his claim that the test was a fizzle. He has pointed out that the key instrumentation—those for measuring acceleration and the ground movement-- were all put in place by the DRDO. “They were in the shaft and radiating outward from the location of the device to the bunkers where the recording instruments were some 2-3 kms away,” he said. He said these had been calibrated “several hundred times” and had little room for malfunction. The readings of the instruments are then factored into mathematical equations that provide estimates of the yield. He has also pointed to the fact that the shaft with the hydrogen bomb device had remained intact, in contrast to the fission bomb one which produced a crater some 35m wide.
While the DAE has claimed that the DRDO’s seismic systems had malfunctioned, they have not yet responded to the fact that there was another, more sophisticated test, called the CORRTEX test. The Corrtex estimates the size of the explosion by measuring the time it takes to crush a cable inserted into the test shaft. In the case of the Pokhran tests, the Terminal Ballistics Laboratory, Chandigarh had a more sophisticated and sensitive system using a fibre-optic cable which gave an estimate of the yield in terms of the time the shock wave takes for the light to be extinguished in the cable.
The ARC is now part of the National Technical Research Office (NTRO) and the scientist who carried out the analysis is still in service with the outfit. And another source has pointed out, that the same facility had given a yield for the 1974 test as being below the than the one claimed.
The history of American technical involvement in monitoring Chinese weapons of mass destruction (WMD) activity is well-known because of the infamous Nanda Devi episode where a nuclear-powered communications intelligence device was emplaced high up on the mountain in the Uttarakhand Himalaya and later it vanished provoking fears of nuclear contamination of the rivers of the Ganga system.
The ARC, whose first head was the legendary Ram Nath Kao, was set up with US technical assistance and was involved in gathering intelligence on China from Tibet. Its task was mainly electronic and photo-intelligence collection from a string of bases in Charbatia, Orissa, Dum Dama, Assam, Sarsawa, U.P. and the Palam airport, Delhi. The monitoring of the Chinese WMD activity was also seen as part of India’s defence effort, though the output was shared with the US, though for how long, is not clear.
A slightly different version was published as the lead story in Mail Today September 18, 2009