In 1967, Indira Gandhi became the prime minister and work on the nuclear programme resumed with renewed vigour. Homi Sethna, a chemical engineer, played a significant role in the development of weapon-grade plutonium, while Ramanna designed and manufactured the entire nuclear device. India's first nuclear bomb project did not employ more than 75 scientists because of its sensitivity. The weapons programme was now directed towards the production of plutonium rather than uranium.
