Padmanabhan Krishnagopalan Iyengar

India lost an eminent nuclear scientist on 21 December 2011 with the death of PK Iyengar at the Bhabha Atomic Research Centre (BARC) hospital in Chembur, east Mumbai. He was 80.
Padmanabhan Krishnagopalan Iyengar (29 June 1931 – 21 December 2011) was a noted nuclear physicist who has known to be played a central role in India's cold fission tests. He was former head of Bhabha Atomic Research Centre (BARC) and former chairman of Atomic Energy Commission of India. He was vocal against the Indo-US civilian nuclear agreement and expressed that the deal favored the USA.
 

Career
Iyengar started his career with the Tata Institute of Fundamental Research (TIFR) in 1952, joined the then atomic energy establishment in Mumbai in 1955, and was soon deputed to the Chalk River Laboratories of the Canadian Atomic Energy Establishment. 
Iyengar was trained in Canada working under Nobel laureate in Physics Bertram Neville Brockhouse, contributing to path-breaking research on lattice dynamics in germanium. 
After returning from Canada, Iyengar built a number of experimental facilities around research reactors APSARA and CIRUS at the BARC. 

He had also played a major part in the design of the Dhruva reactor at Trombay. He became director of BARC in 1984 and was chairman of the atomic energy commission (AEC) between 1990 and 1993.

One of high points in his career came when he successfully led a team to indigenously develop a reactor called ‘PURNIMA - 1’ which was commissioned in 1972. His notable contributions in the field of science are for: 
·         Indian Nuclear Program
·         Operation Smiling Buddha
(Pokhran-I)
·         Operation Shakti (Pokhran-II)
·         Neutron scattering
·         Cold fission
Legacy and Fame
Iyengar has been the recipient of many high civilian awards and honors. In 1975, he was awarded the Padma Bhushan. Research and development activities in several areas such as material science, radiation physics and molecular biology became a reality owing to his efforts. 
Other awards conferred on him:
·         Bhatnagar Award (1971) ·         Federation of Indian Chambers of Commerce and Industry Award for the Physical Sciences (1981) ·         Raman Centenary Medal of the Indian Academy of Science (1988) ·         Bhabha Medal for Experimental Physics of the Indian National Science Academy (1990) ·         R. D. Birla Award of the Indian Physics Association (1992) ·         Jawaharlal Nehru Birth Centenary Award (1993) ·         Homi Bhabha Medal (2006)
Later Career
After retirement Iyengar has served in various positions such as Member of the Atomic Energy Commission, Scientific Advisor to the Government of Kerala, on the Board of the Global Technology Development Centre, President of the Indian Nuclear Society, and a Member of the Inter-governmental Indo-French Forum, besides serving on various national committees. Iyengar’s interests focussed on advances in nuclear technology for nuclear applications, issues of nuclear policy and national security, science education and the application of science in nation-building. Most recently, as a founder trustee of the Agastya International Foundation, he had been focusing on rural education and instilling scientific temperament in rural children.