India’s nuclear stunner: US, France spent billions but failed

India has achieved a major milestone in its nuclear energy journey, as the 500 MWe Prototype Fast Breeder Reactor (PFBR) at Kalpakkam attained first criticality on April 6—marking the start of a self-sustaining nuclear chain reaction.

This breakthrough places India among a select group of nations with advanced fast breeder reactor technology. Currently, only Russia operates such reactors at a commercial scale, while countries like the United States, France, and Japan have struggled to sustain similar programmes.

The achievement is significant for India’s energy future. Unlike conventional reactors, fast breeder reactors generate more nuclear fuel than they consume, allowing India to maximise its limited uranium resources while eventually tapping into its vast thorium reserves—among the largest in the world.

The PFBR is central to India’s long-term three-stage nuclear programme envisioned by Homi Jehangir Bhabha. It enables the transition from uranium-based power to thorium-based energy, paving the way for long-term energy security and reduced dependence on imports.

Prime Minister Narendra Modi described the development as a “defining step” in India’s civil nuclear journey, highlighting its role in strengthening scientific capability and strategic autonomy.

Once fully operational, the Kalpakkam reactor is expected to generate power for millions of homes while producing additional fuel for future reactors—bringing India closer to its goal of large-scale, self-reliant, and clean nuclear energy.