India’s Prototype Fast Breeder Reactor (PFBR) Achieves Criticality at Kalpakkam

Key facts

• India's first Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, Tamil Nadu, achieved criticality on 6 April at 8:25 pm.
• The achievement marks the formal entry into the second stage of India's three-stage nuclear power programme.
• The 500 MWe reactor is designed to produce more fuel than it consumes, making it a self-sustaining nuclear fission chain reaction.
• The PFBR uses a Mixed Oxide (MOX) fuel comprising Plutonium-239 and Uranium-238, with liquid sodium as a coolant.
• India will be the second country after Russia to operate a commercial fast breeder reactor once the indigenously designed unit is commissioned.
• The reactor uses fast neutrons to convert Uranium-238 into fissile Plutonium-239, which will eventually feed stage three reactors.
• Stage three of the programme aims to achieve energy independence by utilising India's thorium reserves, which are the third-largest in the world.
• The Atomic Energy Regulatory Board (AERB) will oversee low power physics experiments before the plant reaches full commercial operation, expected by late 2026 or early 2027.
• Stage one of the national nuclear doctrine involved Pressurised Heavy Water Reactors (PHWRs) using natural Uranium-238 to generate energy and Plutonium-239.