Atomic Energy Commission (AEC) Chairman Anil Kakodkar, the only one to get three extensions in the post, will demit office on November 30.
Kakodkar will also retire from the post of Secretary, Department of Atomic Energy (DAE) on the same day, when his term ends.
"This is the last time I am addressing you from this podium and I wish to thank you all for your strong commitment to the programme and your support to the efforts to sail through the fuel supply crisis," Kakodkar said, addressing the staff during a customary speech at the founder's day celebrations at the Bhabha Atomic Research Centre (BARC).
Coincidentally, October 30 is also the birth centenary of BARC founder Homi J Bhabha.
"Let us resolve with dedication and respect for timeliness and realise the dreams of Homi Bhabha before it is too late and this will be a fitting homage to the memory of Bhabha on his 100th birthday," he told DAE scientists, technologists and administrators.
Kakodkar took over as Chairman, AEC from Dr R Chidambaram in November 2000 and was the first chairman to get three extensions -- in 2003, 2005 and 2007 -- in the history of India's nuclear programme.
Kakodkar was instrumental in initiating and finalising the international civil nuclear cooperation with several nations and also in getting a green signal from the Nuclear Suppliers Group and enabling India to have a nuclear trade waiver.
Current BARC director Dr S Banerjee is likely to succeed as the Chairman of AEC, DAE sources said.
However, the names of new chairman and new BARC director will be announced by the government, Chidambaram, principal scientific advisor to the Centre, said in Mumbai.