Kalpakkam Prototype Fast Breeder Reactor (PFBR) Attains Criticality

Why in News

• The 500 MW Prototype Fast Breeder Reactor (PFBR) at Kalpakkam achieved criticality on April 6, 2026.
• This marks the formal commencement of the second stage of India’s nuclear power programme.
• Criticality means the nuclear fission reaction in the reactor has become safely self-sustaining.
• The project, approved in 2003, took over two decades to reach this milestone.

Impact

• Economic: Aims to produce 80-100 times more energy from a given quantity of uranium compared to existing reactors.
• Social: [NOT RELEVANT]
• Policy: Bridges the gap toward utilizing India’s vast thorium reserves, essential for the third stage of the nuclear programme.
• Ecological: Provides a low-carbon energy baseload, though it requires specialized management of liquid sodium coolant.

GS Paper Focus

GS-3 — Science & Technology: Awareness in the field of Nuclear Technology; Indigenization of technology. POLICIES & SCHEMES: 1. Three-Stage Nuclear Power Programme (Conceived in the 1950s). 2. Atomic Energy Regulatory Board (AERB) oversight. FURTHER READING: * Indira Gandhi Centre for Atomic Research (IGCAR). * Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI). CLUSTER CONNECTION: Ambition vs. Capacity: The project took 23 years to achieve criticality due to the extreme technological complexity of using liquid sodium as a coolant. SYSTEM-LEVEL INSIGHT: The PFBR transition signifies India’s move from being an importer of uranium to a producer of fuel. By using depleted uranium from Pressurised Heavy Water Reactors (PHWRs) to breed Plutonium-239, India is creating a self-sustaining cycle that decouples energy security from global uranium supply chains.

Interview Angle

“Explain why the Prototype Fast Breeder Reactor is considered a ‘bridge’ in India’s nuclear energy roadmap. What are the specific technical risks associated with sodium-cooled reactors?” ENGLISH VOCABULARY & PHRASES: 1. Criticality — state of a nuclear reactor where the fission reaction is self-sustaining — Advanced 2. Fast breeder — reactor that generates more fissile material than it consumes — Intermediate 3. Depleted uranium — uranium with a lower content of the fissile isotope U-235 — Intermediate 4. Thorium reserves — natural radioactive element stores — Basic 5. Self-sustaining — able to continue without external assistance — Basic ________________ ==================== ARTICLE 2 ==================== TOPIC: Electoral Integrity / Voter Rolls EN_BLOCK