India’s 500 MWe Prototype Fast Breeder Reactor (PFBR) has attained first criticality. The milestone came at Kalpakkam, Tamil Nadu, on 6 April 2026 at 8:25 pm. Criticality means the reactor now sustains a controlled fission chain reaction. Notably, the event marks India’s entry into stage two of its three-stage nuclear programme. Thus, a decades-long effort has reached a key goal.
Who Built the Reactor
The Indira Gandhi Centre for Atomic Research (IGCAR) developed and designed the reactor. Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI) built and commissioned it. BHAVINI is a public sector unit under the Department of Atomic Energy. Moreover, the reactor uses mainly indigenous technology and components. DAE Secretary Dr Ajit Kumar Mohanty attended the event.
Safety Clearance
The Atomic Energy Regulatory Board (AERB) carried out a detailed safety review. Then, it cleared the reactor to approach criticality. The plant met all AERB conditions before the start-up.
How a Fast Breeder Works
The PFBR uses uranium-plutonium mixed oxide (MOX) fuel. A blanket of uranium-238 surrounds the core. Fast neutrons turn this uranium-238 into fissile plutonium-239. Therefore, the reactor breeds more fuel than it burns. Also, liquid sodium cools the core. Later, a thorium-232 blanket can produce uranium-233 for stage three.
India’s Three-Stage Nuclear Programme
Homi J Bhabha planned India’s nuclear path in three stages. Stage one uses pressurised heavy water reactors with natural uranium. Stage two uses fast breeder reactors like the PFBR. Finally, stage three will use thorium-based reactors. India holds large thorium reserves, so this path supports long-term energy security.
Prototype Fast Breeder Reactor: Key Facts for Revision
- Capacity: 500 MWe
- Location: Kalpakkam, Tamil Nadu
- First criticality: 6 April 2026, 8:25 pm
- Designer: IGCAR; builder and operator: BHAVINI
- Fuel and coolant: MOX fuel; liquid sodium coolant
- Programme stage: Stage two (fast breeders)
Why the Prototype Fast Breeder Reactor Matters for UPSC and UKPSC
Notably, nuclear energy and the three-stage programme are classic GS Paper III topics. So, remember the capacity, the fuel, the coolant and the two agencies. Also, link the PFBR with India’s thorium reserves. For official updates, also visit the Department of Atomic Energy. Next, for a related story, read about the world’s first nuclear hydrogen plant at Kalpakkam.
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