Kalpakkam: The 500 MWe Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, Tamil Nadu successfully attained first criticality (start of controlled fission chain reaction) at 8.25 pm on Monday. This is being considered a landmark achievement for India’s nuclear energy programme.
The development marks a historic step in providing long-term energy security and advancing indigenous nuclear technology capabilities.
The criticality was achieved after meeting all the stipulations of the Atomic Energy Regulatory Board (AERB), which had issued clearance after a rigorous review of safety of the plant systems, a statement by the Department of Atomic Energy, Government of India, said.
The PFBR was indigenously developed and designed by Indira Gandhi Centre for Atomic Research (IGCAR), an R&D Centre of the Department of Atomic Energy, and was built and commissioned by the Public Sector Undertaking Bharatiya Nabhikiya Vidyut Nigam Ltd (BHAVINI).
Fast Breeder Reactors or FBRs are a cornerstone of India’s long-term nuclear strategy, the statement said. Unlike conventional thermal reactors, the FBRs use Uranium-Plutonium Mixed Oxide (MOX) fuel.
The core of an FBR is surrounded by a blanket of Uranium-238. Fast neutrons convert fertile Uranium-238 into fissil
e Plutonium-239, enabling the reactor to produce more fuel than it consumes. The reactor is designed to eventually use Thorium-232 in the blanket. Through transmutation, Thorium-232 will be converted into Uranium-233, which will fuel the third stage of India’s nuclear power programme.
“This unique capability significantly enhances the utilization of nuclear fuel resources and enables the country to extract far greater energy from its limited uranium reserves while also preparing for large-scale use of thorium in the future,” the statement said.
“With the achievement of first criticality, India moves closer to realizing the full potential of its three-stage nuclear power programme. Fast breeder technology forms the vital bridge between the current fleet of pressurized heavy water reactors and the future deployment of thorium-based reactors, leveraging the country’s abundant thorium resources for long-term clean energy generation,” it added.
This milestone demonstrates the strength of India’s indigenous design, engineering and manufacturing ecosystem. The reactor incorporates advanced safety systems, high-temperature liquid sodium coolant technology and a closed fuel cycle approach that enables recycling of nuclear materials, thereby improving sustainability and reducing waste.
As India continues to expand its clean energy portfolio, fast breeder reactors will play a crucial role in delivering reliable, low-carbon, base-load power with higher thermal efficiency. The attainment of first criticality represents not only a technological milestone but also a major step towards a sustainable and self-reliant energy future for Viksit Bharat.