India has achieved a major nuclear milestone as the indigenously built Prototype Fast Breeder Reactor (PFBR) at Kalpakkam in Tamil Nadu attained criticality on April 6, 2026. This marks a historic step in the country’s nuclear energy program, positioning India among a select group of nations with advanced fast breeder reactor technology.
The PFBR, developed by Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI) under the Department of Atomic Energy, is designed to generate 500 MWe of electricity. It uses a mixed oxide of plutonium and uranium as fuel, with liquid sodium serving as coolant. The reactor’s criticality signifies the start of its controlled nuclear chain reaction, paving the way for eventual commercial power generation.
Officials highlighted that the PFBR is a cornerstone of India’s three-stage nuclear program, aimed at achieving long-term energy security by utilizing thorium reserves. The reactor will produce more fuel than it consumes, enabling sustainable expansion of nuclear power capacity in the country.
The achievement has drawn praise from scientists and policymakers, who described it as a testament to India’s indigenous technological capabilities. It is expected to accelerate India’s transition toward clean energy, reduce dependence on fossil fuels, and strengthen self-reliance in strategic nuclear technology.
With the PFBR attaining criticality, India has taken a decisive step toward harnessing advanced nuclear energy systems, reinforcing its position as a global leader in sustainable energy innovation.
