India’s First Fast Breeder Reactor Marks 40 Years of Operation at Kalpakkam

India’s pioneering Fast Breeder Test Reactor (FBTR) at Kalpakkam is poised to celebrate a historic milestone as it completes 40 years of successful operation on October 18, 2025.

Operated by the Indira Gandhi Centre for Atomic Research (IGCAR), the FBTR first went critical on October 18, 1985. The 40 MW thermal / 13.6 MW electrical sodium-cooled fast reactor uses a unique blend of plutonium carbide and uranium carbide as fuel — making it the first of its kind in India’s ambitious nuclear energy programme.

Although no large-scale celebration is planned, IGCAR will reportedly host a small gathering of current and former Directors to commemorate the achievement.

The reactor reached its design power level of 40 MWt on March 7, 2022, after beginning operations with a smaller 22 Mark-I fuel core rated at 10.5 MWt in 1985. Over the years, the power level was steadily increased through innovative core designs, safety enhancements, and regulatory approvals from the Atomic Energy Regulatory Board (AERB).

The success of the FBTR stands as a cornerstone of India’s nuclear research and energy development, paving the way for future projects — including the Prototype Fast Breeder Reactor (PFBR) currently under construction at Kalpakkam by Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI).

This achievement not only marks a technological triumph but also reinforces India’s commitment to advancing its self-reliant nuclear energy programme for sustainable development.