India has achieved a significant breakthrough in its nuclear energy programme with the indigenously designed and built Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, Tamil Nadu, achieving its first criticality on 6th April 2026. This milestone marks the initiation of a sustained nuclear chain reaction in the 500 MWe reactor, built by Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI) at the Kalpakkam Nuclear Complex.
The successful criticality of the PFBR officially takes India into the second stage of its three-stage nuclear power programme, a vision originally conceived by Dr. Homi Jehangir Bhabha. Once fully operational, India will become only the second country in the world, after Russia, to operate a commercial fast breeder reactor. This achievement is not only a testament to decades of scientific effort led by the Department of Atomic Energy but also strengthens India’s clean energy journey and its commitment to low-carbon power.
India’s nuclear programme is designed around a three-stage strategy to maximize its limited uranium reserves and vast thorium resources. Stage 1 uses Pressurised Heavy Water Reactors (PHWRs) fueled by natural uranium, producing plutonium for Stage 2. Stage 2, represented by the PFBR, uses plutonium as fuel and breeds more fissile material than it consumes, laying the foundation for Stage 3, which will harness thorium to achieve long-term energy security.
The PFBR is a product of decades of indigenous research and development led by the Indira Gandhi Centre for Atomic Research (IGCAR). It uses Uranium-Plutonium Mixed Oxide (MOX) fuel and a core surrounded by Uranium-238 to breed plutonium. Eventually, the reactor will utilize Thorium-232 to produce Uranium-233, completing the second stage fuel cycle and setting the stage for large-scale thorium deployment.
Currently, India’s nuclear power contributes about 3% to the nation’s electricity generation, with an installed capacity of 8.78 GW. With plans for indigenous 700 MW and 1,000 MW reactors, the capacity is expected to reach 22.38 GW by 2031–32. International cooperation through civil nuclear agreements with 18 countries further strengthens India’s global nuclear standing.
Under the Nuclear Energy Mission, India aims to achieve 100 GW of nuclear capacity by 2047, supporting the nation’s goal of net zero carbon emissions by 2070. Financial commitments of Rs 20,000 crore have been allocated for the development of Small Modular Reactors (SMRs) and next-generation reactor designs, backed by initiatives from Bhabha Atomic Research Centre (BARC) and regulatory frameworks like the SHANTI Act, 2025.
The PFBR’s criticality marks a historic moment in India’s nuclear journey, demonstrating the maturity of the country’s nuclear programme and its indigenous capabilities. From limited uranium reserves to a thorium-powered future, India’s three-stage nuclear strategy is steadily moving from vision to reality, strengthening energy security, technological self-reliance, and commitment to a low-carbon future.
Nurturing Creativity – Keekli Charitable Trust, Shimla
