New Delhi, April 7, 2026: India has marked a significant advancement in its nuclear energy programme with the successful attainment of first criticality of the 500 MWe Prototype Fast Breeder Reactor (PFBR) at Kalpakkam. The milestone was achieved on April 6, 2026, at 08:25 PM, signifying the initiation of a controlled nuclear fission chain reaction.
This achievement represents a crucial step toward enhancing India’s long-term energy security and strengthening its indigenous nuclear technology capabilities.
The criticality was accomplished after meeting all safety and regulatory requirements laid down by the Atomic Energy Regulatory Board, following a comprehensive review of the plant’s systems and operational readiness. The event was witnessed by senior officials and scientists from India’s nuclear establishment, including Ajit Kumar Mohanty, Secretary, Department of Atomic Energy and Chairman, Atomic Energy Commission.
The PFBR has been indigenously designed by the Indira Gandhi Centre for Atomic Research and constructed by BHAVINI, reflecting India’s growing strength in advanced nuclear engineering and commitment to technological self-reliance.
Fast Breeder Reactors play a pivotal role in India’s three-stage nuclear power programme. Unlike conventional reactors, the PFBR uses Uranium-Plutonium Mixed Oxide (MOX) fuel and is capable of generating more fissile material than it consumes. This process enables better utilization of nuclear fuel resources and supports the long-term goal of harnessing thorium-based energy.
The reactor is also equipped with advanced safety features, liquid sodium cooling technology, and a closed fuel cycle system, ensuring higher efficiency, sustainability, and reduced nuclear waste.
This milestone underscores the dedication and expertise of scientists, engineers, and industry partners involved in the project. It also strengthens India’s position in the global nuclear energy landscape while contributing to the vision of a clean, reliable, and sustainable energy future.
The successful commissioning of PFBR marks a major step forward in achieving energy independence and supporting the nation’s growing power needs through low-carbon energy sources.
