April 7, 2026
India advances nuclear ambitions as Fast Breeder Reactor at Kalpakkam attains criticality
In a landmark achievement for its civil nuclear energy programme, India has announced that its most advanced domestically designed nuclear reactor has reached “criticality” — the point at which a reactor begins a controlled, self‑sustaining nuclear chain reaction.
The milestone involves the Prototype Fast Breeder Reactor (PFBR), a 500‑megawatt electric facility located at Kalpakkam, near the city of Chennai, in India’s southern state of Tamil Nadu.
The development — which was announced by Prime Minister Narendra Modi on Monday night — marks a crucial step towards full operation and generation of power.
It also advances the second stage of the country’s three-step nuclear programme.
Modi described the milestone as a “defining” step in India’s civil nuclear quest and a “proud moment” for the country.
“The indigenously designed and built Prototype Fast Breeder Reactor at Kalpakkam has attained criticality,” Modi wrote on X.
“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,” he said.
The prime minister added that it was a “decisive step” towards India harnessing its vast thorium reserves in the third stage of the programme.
Thorium is a potential fuel for nuclear reactors.
In 2024, Modi had taken a tour of the facility to witness the commencement of core loading.
India — the third-largest emitter of greenhouse gases — is on an ambitious journey to expand its nuclear power capacity from the current eight to 100 gigawatts by 2047.
Fast Breeder Reactors are significant because they can generate more fissile material than they use, making them valuable for countries seeking long‑term nuclear sustainability.
Once fully operational, India will only be the second country, after Russia, to have a commercial operating Fast Breeder Reactor.
