India's nuclear fuel self-reliance has taken a significant step forward after a domestically designed reactor achieved a controlled nuclear reaction, marking progress in the country’s long-term energy and climate strategy.
The Prototype Fast Breeder Reactor at Kalpakkam has reached “criticality”, the stage at which a self-sustaining nuclear chain reaction begins. This milestone is a key step before the reactor can start generating electricity for the national grid.
Prime Minister Narendra Modi said the development represents a major advance in India’s civil nuclear programme. “Today, India takes a defining step in its civil nuclear journey, advancing the second stage of its nuclear programme,” he said.
“This advanced reactor, capable of producing more fuel than it consumes, reflects the depth of our scientific capability and the strength of our engineering enterprise.”
The reactor is part of India’s broader strategy to utilise its large thorium reserves, which are seen as a long-term alternative to conventional nuclear fuel. Modi described the progress as a “decisive step towards harnessing our vast thorium reserves”.
Although the reactor has reached criticality, it is not yet supplying electricity. Further testing and operational phases are required before it reaches full power generation.
The development comes as India seeks to expand its nuclear energy capacity from around eight gigawatts to 100 gigawatts by 2047. The expansion is part of a wider effort to reduce reliance on fossil fuels and strengthen energy security.
India remains heavily dependent on coal, even as it has committed to achieving net-zero emissions by 2070. The push towards nuclear energy is expected to play a central role in meeting rising energy demand while reducing greenhouse gas emissions.
The milestone also comes amid global energy uncertainty linked to geopolitical tensions, including conflict in the Middle East, which has raised concerns about fuel supply disruptions and energy security.
