India achieved a major milestone on April 6, 2026, with the first criticality of the 500 MWe Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, Tamil Nadu. This marks the start of a self-sustaining nuclear chain reaction. Developed by BHAVINI under the Department of Atomic Energy, the PFBR is part of India’s second stage nuclear programme. It produces more fuel than it consumes and supports long-term energy security using thorium resources.
The 500 MWe Prototype Fast Breeder Reactor (PFBR) reached first criticality on April 6, 2026, at Kalpakkam in Tamil Nadu. Criticality means the reactor has started a controlled and self-sustaining nuclear chain reaction. This milestone was achieved in the presence of scientists from the Department of Atomic Energy (DAE) and Atomic Energy Commission (AEC).
The PFBR is developed by BHAVINI, a public sector enterprise. It uses Mixed Oxide (MOX) fuel made of Uranium and Plutonium. It also uses liquid sodium as coolant, which allows operation at high temperatures.
It also aligns with Atmanirbhar Bharat and Viksit Bharat goals by promoting indigenous nuclear technology.
Q1. PFBR achieved first criticality in which year?
A) 2024
B) 2025
C) 2026
D) 2023
Answer: C
Q2. Which organization constructed PFBR?
A) NPCIL
B) BARC
C) BHAVINI
D) ISRO
Answer: C
Q3. PFBR belongs to which stage of nuclear programme?
A) First
B) Second
C) Third
D) Fourth
Answer: B
Q4. What coolant is used in PFBR?
A) Heavy Water
B) Light Water
C) Liquid Sodium
D) Graphite
Answer: C
Q5. What is the main feature of breeder reactors?
A) Consume more fuel
B) Produce less energy
C) Produce more fuel than consumed
D) Use only thorium
Answer: C
Question: Which stage of India’s nuclear programme uses thorium?
A) First
B) Second
C) Third
D) Fourth
Answer: C
Students often confuse PHWR and FBR reactors. PHWR uses heavy water, while FBR uses liquid sodium.
Focus on stages of nuclear programme, fuel types, and coolant differences for prelim questions.