India Achieves Milestone with First Criticality of Prototype Fast Breeder Reactor

New Delhi. A significant milestone has been achieved in India's nuclear energy program. The 500 MW Prototype Fast Breeder Reactor located in Kalpakkam, Tamil Nadu, successfully achieved its first criticality (controlled nuclear fission process) at 8:25 PM on 6 April 2026. 

The process was initiated following strict safety standards and reviews by the Atomic Energy Regulatory Board. The event was attended by top scientists and officials, including Dr. Ajit Kumar Mohanty, Chairman of the Atomic Energy Commission of India. 

The design and technology of this reactor were developed indigenously by the Indira Gandhi Centre for Atomic Research, while its construction and operation were managed by Bharatiya Nabhikiya Vidyut Nigam Limited.

The Fast Breeder Reactor is considered a key pillar of India's long-term nuclear strategy. Compared to conventional thermal reactors, it utilizes uranium-plutonium mixed oxide fuel. A unique feature of this technology is that it produces more fuel than it consumes. 

In the future, this reactor will use Thorium-232 to produce Uranium-233, paving the way for utilizing India's abundant thorium reserves for energy production.

The reactor is equipped with advanced safety systems such as high-temperature liquid sodium coolant technology and a closed fuel cycle. It helps in sustainable energy production while minimizing nuclear waste. As a result of years of hard work by Indian scientists, engineers, and technicians, India is now very close to entering the third stage of its thorium-based nuclear energy program.