India has achieved a significant milestone in nuclear technology with the successful criticality of the 500 MWe Prototype Fast Breeder Reactor (PFBR) at Kalpakkam on April 6, 2026. Developed by BHAVINI and Indira Gandhi Centre for Atomic Research, the PFBR is among the country’s most advanced nuclear reactors and represents a key step in India’s long-term energy programme.

The reactor is designed to utilise plutonium-based fuel and support India’s three-stage nuclear strategy, which aims to tap into the country’s vast thorium reserves eventually. Fast breeder reactor technology remains complex, with only a few countries, including Russia, operating such systems at a commercial level, while others continue to face technical and economic challenges.

The development underscores India’s progress in advanced nuclear research and its efforts to strengthen energy security. It is also expected to contribute to a more sustainable and diversified energy mix, reducing dependence on conventional fuel sources over the long term.