India has achieved a major milestone in its nuclear energy program as the indigenously designed and built Prototype Fast Breeder Reactor (PFBR) at Kalpakkam in Tamil Nadu has achieved criticality.
Prime Minister Narendra Modi has praised this landmark achievement. In a social media post last night, PM Modi said that India is taking a defining step in its civil nuclear journey, advancing the second stage of the country's three-stage nuclear program. Highlighting the technological significance of the reactor, the Prime Minister said that this advanced reactor, capable of producing more fuel than it consumes, reflects the depth of the nation's scientific capability and the strength of its engineering enterprise. The Prime Minister also called this a decisive step towards harnessing India's vast thorium reserves in the third stage of the program. Calling it a proud moment for India, PM Modi congratulated the scientists and engineers involved in the project.
The 500-megawatt electric (MWe) PFBR is located in Kalpakkam, Tamil Nadu and is operated by Bharatiya Nabhikiya Vidyut Nigam Ltd (BHAVINI). It represents a key component of India's long-term nuclear strategy. Once fully operational, India will become the second country after Russia to have a commercial fast breeder reactor.
Criticality marks the point at which a nuclear reactor achieves a self-sustaining chain reaction. This is a key milestone before full power generation, indicating that the reactor core is functioning as designed. It strengthens India's position in advanced nuclear technology and clean energy generation.
The project has been built indigenously with contributions from over 200 Indian industries, including several MSMEs, aligning with the government's push for self-reliance under the Aatmanirbhar Bharat initiative.
Fast Breeder Reactors are designed to generate more fissile material than they consume. The PFBR uses Uranium-Plutonium Mixed Oxide (MOX) fuel, while a surrounding "blanket" of Uranium-238 undergoes transmutation to produce additional fuel. In later stages, Thorium-232 will be used to produce Uranium-233, paving the way for the third stage of India's nuclear program and enabling the utilization of the country's vast thorium reserves.
The reactor is also equipped with advanced passive safety features, ensuring automatic and safe shutdown in case of emergencies.