Indian Prime Minister Indira Gandhi gave authorization to the scientists at the Bhabha Atomic Research Centre (BARC), Trombay to detonate an indigenously designed nuclear device. Throughout its development, the device was formally called the "Peaceful Nuclear Explosive", but it was usually referred to as the Smiling Buddha.
The team was Headed by Rajagopala Chidambaram. The team consisted of Abdul Kalam(Tamilnadu),P.K.Iyengar(Kerala),RajagopalaChidambaram(Tamilnadu),Nagapattinam Sambasiva Venkatesan(Andhra Pradesh) and Dr.Waman Dattatreya Patwardhan(Maharashtra). The project employed no more than 75 scientists and engineers from 1967-1974. Keeping it small served to aid in the preservation of secrecy, according to the researcher Jeffrey Richelson.
The device used a high explosive implosion system, developed at the Defence Research and Development Organisation (DRDO)'s Terminal Ballistics Research Laboratory (TBRL), Chandigarh, based on the American design from World War II. But the Indian design was simpler and less sophisticated than the American system.The detonation system to detonate implosion devices was developed at the High Energy Materials Research Laboratory (HEMRL) of DRDO at Pune. The 6 kg of plutonium came from the CIRUS reactor at BARC, Trombay, Mumbai (then Bombay). The neutron initiator was a Polonium-Beryllium type (again like those used in early U.S. bombs of the Fat Man type) code-named "Flower." The complete core was assembled in Trombay before transportation to the test site. Prof.Dr. Abdul Kalam, was the pioneer behind the launch. An aeronautical engineer from Tamilnadu paved the way for India's ascent into an elite group of Nuclear states. Fondly called as 'Missile Man of India', he later went on to become the President of India.
The fully assembled device had a hexagonal cross section, 1.25 m in diameter and weighed 1400 kg. The device was detonated at 8.05 a.m. in a shaft 107 m under the army Pokhran test range in the Thar Desert (or Great Indian Desert), Rajasthan. Officially the yield was reported at 12 kt, though outside estimates of the yield vary from 2 kt to 20 kt. Pokhran is the test site for India's nuclear program. The Atomic Energy Commission of India detonated its first underground nuclear weapon there on May 18, 1974. The Indian government, however, declared that it was not going to make nuclear weapons even though it had acquired the capacity to do so. It claimed that the Pokhran explosion was an effort to harness atomic energy for peaceful purposes and to make India self-reliant in nuclear technology, but subsequently, India conducted five nuclear tests on May 11 and May 13, 1998. Since then, India has declared a moratorium on the testing.