R Chidambaram, one of the architects of India’s nuclear programme, dies at 88

One of the very few scientists closely involved in both of India’s nuclear tests — in 1974 and 1998 — Chidambaram was the guiding force behind India’s nuclear self-reliance and its emergence as an overt nuclear power in the last three decades.

And the idea to explode a thermonuclear device — the hydrogen bomb — during the 1998 tests could be largely attributed to him.

“I know many secrets and I would like to happily die with them,” Chidambaram had said, laughing, when this correspondent sought some information during a meeting in Mumbai in 2022.

“Deeply saddened by the demise of Dr Rajagopala Chidambaram,” Prime Minister Narendra Modi said in a message on social media platform X. “He was one of the key architects of India’s nuclear programme and made ground-breaking contributions in strengthening India’s scientific and strategic capabilities. He will be remembered with gratitude by the whole nation and his efforts will inspire generations to come.”

Chidambaram had retired from the Atomic Energy Commission in 2000, after receiving two extensions, but was soon appointed to succeed Dr A P J Abdul Kalam as the Principal Scientific Advisor, a post created in the wake of the 1998 nuclear tests. He served in that position for an extraordinary 17 years, working with three Prime Ministers — Atal Bihari Vajpayee, who had appointed him, Manmohan Singh, who negotiated a landmark civil nuclear deal with the US, and Modi — all of whom found him too invaluable to let go.

“I am already 77. You may like to have a new PSA,” he told Modi in 2014, according to his own account in a book he co-authored with fellow nuclear scientist Suresh Gangotra last year.

“‘What has age got to do with science,’ he (Modi) asked me. Then I told him that I had worked with several PMs, the last one being Dr Manmohan Singh, from the Congress party. To that, he asked me ‘What has politics got to do with science?’ So, I continued as the PSA to the government for the next five years,” Chidambaram wrote in the book.

His value was much more than that of a scientific advisor. He had been one of the central characters in the evolution of the nuclear programme, having contributed to it enormously himself, and had a strategic vision for the long-term interests of the country.

It was around 1967 that Chidambaram, then in his early 30s, was picked by Raja Ramanna, another stalwart of India’s nuclear programme, to solve a critical problem necessary in the design of a nuclear explosive. “I was surprised when he asked me to take up this work because this was a completely different field from what I was working on,” Chidambaram wrote in the book.

He was asked to derive what was known as the ‘equation of state’ of plutonium, an equation that describes the relation between temperature, pressure and density of the substance when the nuclear fission reaction takes place. In particular, scientists were interested in the behaviour of materials when they were compressed under very high pressures.

This kind of information for nuclear materials, absolutely necessary for carrying out controlled fission reactions, used to be a tightly guarded secret and not available in public domain at that time. It needed to be worked out from the scratch. Chidambaram and his team did eventually solve this problem, which paved the way for the finalisation of the design of a nuclear device by 1971.

Incidentally, Ramanna, Chidambaram and some other colleagues had been planning and preparing for a nuclear test even when the political establishment of the time was completely unsure about taking such a step. But the progress they were able to make during this time ensured that when the political leadership finally took a call on conducting a test, they were able to deliver it in a relatively short time.

Chidambaram was in the small group of nuclear scientists who argued that India must not forego its option to develop nuclear weapons till such time other countries possessed them.

He rose to become the director of Bhabha Atomic Research Centre in 1990 and chairman of Atomic Energy Commission in 1993, all the while pushing for another round of tests which finally happened in 1998, dodging the surveillance satellites and escaping prior detection of other countries.

At a public event in Chennai in 1999, when it was suggested that instead of carrying out the tests India should have kept its nuclear option ‘open’, Chidambaram replied that keeping the option open indefinitely was like keeping one’s marriage option open indefinitely. “At some point, you become unfit for marriage and finally impotent. It is good that we tested before we became nuclear-impotent,” he said.

Curiously, Chidambaram faced questions over the credibility of thermonuclear tests from some of his own colleagues in the nuclear establishment. He patiently rebutted each of their claims on scientific facts without ever getting personal.

The 1998 tests were his crowning achievement, but not the end of his sterling career. The tests had triggered international rebuke and sanctions, and Chidambaram found himself actively involved in a different kind of role, trying to end India’s nuclear isolation in the international community. Simultaneously, he was guiding the development and deployment of delivery systems, and the operationalisation of the full-scale nuclear weapons capability, what is known as the development of the nuclear triad, the ability to launch nuclear weapons from land, air or sea.

Much of his tenure as the Principal Scientific Advisor was devoted to these two tasks. In fact, it was precisely these tasks that kept him in this position for so long. Chidambaram was not an official negotiator on the India-US civil nuclear cooperation agreement. Neither was he the decision-maker on the weaponisation activities of the armed forces. But he was one of the most active players behind the scenes, advising the Prime Ministers on the best way forward.

“Dr Chidambaram is very different from the previous chairmen of the AEC (Atomic Energy Commission). Previous chairs like Homi Sethna, Raja Ramanna and (P K) Iyengar, were responsible for the technical and nuclear side of our programme. But they largely left it to the PM or the government to handle international repercussions. Dr Chidambaram, therefore, is the first AEC chairman who not only dealt with his regular work, which is looking after the nuclear programme, but also gave critical guidance on how to handle international pressure,” wrote D B Venkatesh Varma, India’s former Ambassador to Russia, in a chapter in the book authored by Chidambaram and Gangotra.

“He made critical interventions at very critical points during the negotiations on the nuclear deal,” Varma told The Indian Express.

“We tend to take for granted the difficulties that Chidambaram’s generation went through in going ahead with the development of our nuclear programme. It required huge effort and vision of people like Chidambaram,” he said.