India marked a pivotal moment in its energy landscape on April 6, 2026, when the Prototype Fast Breeder Reactor (PFBR) at Kalpakkam achieved criticality, initiating a controlled nuclear chain reaction in its 500 MWe reactor. This achievement signifies India's entry into the second stage of its three-stage nuclear power program, originally envisioned by Homi J. Bhabha. The PFBR, developed by Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI) and the Indira Gandhi Centre for Atomic Research, is designed to multiply usable nuclear fuel, particularly leveraging India's abundant thorium reserves. Unlike conventional reactors, the PFBR uses mixed oxide fuel and has the capability to produce more fuel than it consumes, thereby enhancing energy efficiency significantly.

The reactor's breeding capability positions it as a strategic asset for India, which faces limitations in uranium supply. With projections indicating a rise in nuclear power capacity from the current 8.78 GW to over 22 GW by the early 2030s, and a long-term goal of 100 GW by 2047, the PFBR serves as a proof of concept for a future where India can achieve energy sovereignty. This development comes amid geopolitical uncertainties, emphasizing the need for India to reduce its reliance on imported fossil fuels. The successful operation of the PFBR will make India only the second country, after Russia, to operate a commercial-scale fast breeder reactor, showcasing the nation's advanced indigenous manufacturing capabilities.