Itanagar, April 7: The Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, Tamil Nadu, achieved first criticality on Tuesday, marking the start of a controlled nuclear fission chain reaction, officials said.

Arunachal Pradesh Chief Minister Pema Khandu described the milestone as a significant step for India’s clean energy sector. He highlighted the reactor’s indigenous design and domestic technology, noting that it strengthens India’s nuclear energy strategy and energy security.

Developed by the Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI), the 500 MWe sodium-cooled fast breeder reactor is part of India’s three-stage nuclear power program. The reactor is designed to produce more fissile material than it consumes by converting uranium-238 into plutonium, enabling the future use of India’s thorium reserves for sustainable energy generation.

Khandu acknowledged the contribution of scientists, engineers, and technical teams in realizing the project and noted that the achievement reflects advances in India’s research and innovation capabilities.