CHENNAI: India on Monday achieved a major milestone in its civil nuclear programme, with the Prototype Fast Breeder Reactor (PFBR) at Kalpakkam attaining criticality, the stage at which a controlled, self-sustaining nuclear chain reaction begins.
Prime Minister Narendra Modi described it as a “defining step” in advancing the second stage of India’s nuclear programme. “The indigenously designed and built Prototype Fast Breeder Reactor at Kalpakkam has attained criticality… a decisive step towards harnessing our vast thorium reserves,” he said in a post on X, congratulating scientists and engineers.
The 500 MWe PFBR, developed by Indira Gandhi Centre for Atomic Research and operated by BHAVINI, is India’s first fast breeder reactor, a technology that produces more nuclear fuel than it consumes. Using plutonium-based fuel and liquid sodium as coolant, the reactor converts non-fissile uranium-238 into fissile material, improving fuel efficiency and reducing waste.
The milestone follows clearance from the Atomic Energy Regulatory Board in 2024 for fuel loading and low-power physics experiments.