India's Prototype Fast Breeder Reactor (PFBR), located in Kalpakkam, Tamil Nadu, is on track to become operational by the end of 2025. This 500 MWe sodium-cooled reactor is a significant advancement in India's nuclear energy capabilities and is designed to utilize the country's abundant thorium reserves effectively.

Core loading for the PFBR commenced in March 2024, marking a crucial phase towards achieving criticality. This process involves inserting control and blanket sub-assemblies into the reactor core, which is being conducted under the stringent oversight of the Atomic Energy Regulatory Board (AERB) .

On July 27, 2024, the AERB granted permission for the "First Approach to Criticality," allowing for the introduction of fuel into the reactor core and the initiation of low-power physics experiments. This approval follows extensive safety reviews and inspections .

The PFBR is expected to achieve criticality and begin generating power by late 2025. This timeline follows numerous delays since its construction began over two decades ago, originally projected to be completed in 2010 .

The PFBR employs a mixed uranium-plutonium MOX fuel and utilizes liquid sodium as a coolant. It is designed to breed more plutonium than it consumes, enhancing fuel sustainability .

Following successful operation of the PFBR, India plans to construct additional fast breeder reactors, furthering its nuclear energy program and reducing dependency on imported nuclear fuel .

The operationalization of the PFBR represents a pivotal step in India's pursuit of energy security and its goal to leverage indigenous nuclear technology for sustainable energy production.