Question mark over India’s nuclear test of 1998

Shocking revelation by K Santhanam, chief coordinator of Pokhran-II N-tests

K. SANTHANAM, the Defence Research and Development Organisation official who coordinated India’s nuclear weapons programme during the Pokhran nuclear tests in 1998, has thrown a bombshell.
He has declared that the first and most powerful of the three tests conducted on May 11 that year – a thermonuclear or hydrogen bomb – was a “fizzle.”


This is the first time that a top-ranked figure, directly associated with the nuclear weapons programme, has acknowledged the test had not been as successful as was trumpeted at the time.
Prime Minister Atal Bihari Vajpayee himself had acknowledged at the time that India had tested a"big" bomb among the five tests it had conducted on May 11 and 13. This was later confirmed by Department of Atomic Energy (DAE) Chief R. Chidambaram who had said that the bomb's yield was 45 kilotonnes (45,000 tonnes of conventional explosive).
Santhanam made the remarks at a semi-public seminar on the Comprehensive Test Ban Treaty at the Institute of Defence Studies and Analyses on Tuesday that followed off-the-record Chatham House rules (where the identity of the speaker is not revealed, although what he or she said can be freely quoted).
However, after reports of his remarks appeared in a section of the media, he said on Wednesday that his recollection of his statements was slightly more nuanced. His view was that India should not sign the CTBT and that it needed to conduct more thermonuclear tests.
“There is no country in the world,” he emphasised, “which managed to get its thermonuclear weapon right in just one test.” He said that he had also pointed to the fact that western seismic experts had doubted India’s claim that the three simultaneous tests on May 11 had a combined explosives yield of 60 kt.
The Santhanam revelation could have major reverberations in the country’s security policy. The Indo-US nuclear deal, for instance, rests upon the assumption that India will not test again.
It is also likely to make it difficult for the Manmohan Singh government to sign the CTBT, an issue that has gained considerable salience in the Obama administration’s non-proliferation policy.
The doyen of nuclear weapons scientists, P.K. Iyengar, who had retired by the time the Pokhran tests were conducted, made a similar statement in scientific language in a newspaper article in 2000. He noted that “the secondary (fusion) device burnt only partially, perhaps less than 10 per cent”.
Thermonuclear weapons are much more powerful than atomic weapons and they work in two stages: a normal plutonium implosion device (primary) acts as a trigger to set off a fusion or thermonuclear process (secondary) that releases a vast amount of energy. Thus while the fission bombs that destroyed Hiroshima, or the type that India tested in Pokhran-I in 1974 had an explosive yield of 12-15 kt, thermonuclear or hydrogen bombs can be anywhere from 200 kt to a megaton.
Santhanam’s doubts about the hydrogen bomb after the Pokhran tests were first featured, on an unattributable basis, in security analyst Bharat Karnad’s book India’s Nuclear Policy (2008) where he pointed out that “a senior DRDO official involved in the testing” had, some six months after the tests, “recommended resumption of testing to the government because he was convinced that the test of the hydrogen bomb was inadequate”.
Karnad, a professor at the Centre for Policy Research, felt that the Indian need to test again “is less a matter of opinion than of fact.”
In his view, Santhanam’s “extremely courageous stand” had struck a fatal blow at the foundation of the Indo-US nuclear deal “predicated on India’s never testing again and at any accommodationist policies the Manmohan Singh regime may be considering vis-a-vis the CTBT and the Fissile Material Cutoff Treaty”.



At a press conference following the test in May 1998, DAE chief Chidambaram claimed that they had deliberately kept the secondary of the thermonuclear Shakti-I explosion low so as not to damage a nearby village. But this claim was met with scepticism.
The first doubts on the test were cast by western seismic experts who questioned the 6o kt total yield for the three tests of May 11. US intelligence sources had also raised questions about whether India’s claim of testing a “thermonuclear device” actually amounted to a hydrogen bomb. They believed that it could have been a “boosted” fission device.
Scientists from the Bhabha Atomic Research Centre in Mumbai insisted all along that all the tests, including the hydrogen bomb or thermonuclear test, had been successful. They followed this up by publishing a series of papers arguing that the yields were in accordance with the design objectives.
Two papers by S.K. Sikka and DAE chief R. Chidambaram had debunked the western seismic analyses. In various issues of the BARC Newsletter in 1999, scientists had provided radio-chemical analysis backing up the official claims that the yields were as expected.
Santhanam’s revelation is likely to be like a bucket of cold water on the security establishment in the country.
India claims that it is second to none as a military power. It is building a nuclear triad — basing nuclear weapons on land, air and sea — just like the US, China and Russia.
But the lack of a weapon of adequate explosive yield undermines Indian claims of possessing world-class strategic capability and damages its nuclear force posture.
Asked why Santhanam might have decided to go public now, Karnad said that it was his belief that “as a nuclear scientist who has always dealt in physical certainties, try as he might Santhanam could not reconcile the physical facts of deficiencies in the design of the thermonuclear device evidenced in the test results with the profession of satisfaction by the government with the same results.”
He said that for reasons best known to him, the DAE chief Chidambaram had claimed success, a position that had undermined the credibility of India’s deterrent posture and brought into question the reliability of the unproven thermonuclear armaments in the country’s arsenal.
This was the lead story in Mail Today on August 27, 2009