India Marks Major Achievement in Nuclear Sector as Kalpakkam Reactor Achieves Criticality

April 7, 2026

New Delhi: India’s nuclear energy program has achieved a major milestone: Prototype Fast Breeder Reactor (PFBR) in Kalpakkam, Tamil Nadu, has reached criticality.

PM Modi Congratulates

Prime Minister Narendra Modi described this achievement as an important step in India’s civil nuclear journey. He said it advances the second phase of the country’s three-stage nuclear program.

Highlighting the reactor’s technical capabilities, he said it can produce more fuel than it consumes. He called it a significant step towards utilizing India’s vast thorium reserves and congratulated the scientists and engineers.

Specialities of the PFBR

This 500 MW prototype fast breeder reactor is located in Kalpakkam and is operated by the Bharatiya Nabhikiya Vidyut Nigam Limited.

Once fully operational, India will become the second country, after Russia, to operate such a reactor.

What is Criticality

Criticality is the state when a self-sustaining nuclear chain reaction begins in the reactor. This is a crucial stage before power generation at full capacity and indicates that the reactor is functioning properly.

Promoting Self-Reliance and Clean Energy

This project is completely indigenous, with contributions from over 200 Indian industries, especially MSMEs. It strengthens the Atmanirbhar Bharat initiative and further strengthens India’s position in the clean energy sector.