India has brought a long-delayed but strategically important nuclear project to a key operational milestone.
The 500 MWe Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, Tamil Nadu, has now reached criticality, signaling that the reactor core has begun sustaining a controlled fission process.
The development places India among a small group of nations operating fast breeder reactor technology at this scale.
Indian Prime Minister Narendra Modi announced the milestone on X, framing it as a major step forward in the country’s nuclear roadmap.
“Today, India takes a defining step in its civil nuclear journey, advancing the second stage of its nuclear programme. The indigenously designed and built Prototype Fast Breeder Reactor at Kalpakkam has attained criticality.”
He added: “This advanced reactor, capable of producing more fuel than it consumes, reflects the depth of our scientific capability and the strength of our engineering enterprise. It is a decisive step towards harnessing our vast thorium reserves in the third stage of the programme. A proud moment for India. Congratulations to our scientists and engineers,” Modi said.
Built for fuel multiplication
Unlike conventional reactors, the PFBR is designed to create more fuel than it burns.
It runs on mixed oxide fuel, combining uranium-238 and plutonium-239, and uses liquid sodium as a coolant.
This configuration allows the reactor to convert fertile material into fissile fuel during operation.
Engineers consider this capability critical for sustaining long-term nuclear energy programs.The reactor was designed by the Indira Gandhi Centre for Atomic Research and built by Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI).
Both operate under India’s Department of Atomic Energy.
The project has faced delays and cost escalations since construction began in 2004.
Engineers also adapted the fuel handling system after technical issues with the original transfer mechanism, switching to an alternate approach.
Strategic shift toward thorium
India’s nuclear program follows a phased structure to manage limited uranium reserves.Fast breeder reactors anchor the second stage of this plan.
The PFBR is expected to generate fissile material that supports a future transition to thorium-based fuel cycles. India holds some of the world’s largest thorium reserves, making this shift strategically significant.
Officials see the reactor as a bridge between current uranium-based systems and a more sustainable thorium-driven future.
This transition could strengthen energy security and reduce dependence on imported nuclear fuel.
Plans for additional breeder reactors at Kalpakkam highlight India’s intent to scale this technology further.
Reaching criticality does not mean the reactor is ready to supply electricity at full capacity.
It marks the beginning of a gradual commissioning process.
Operators will now raise power levels in stages while conducting detailed performance checks.
These steps ensure the reactor operates within strict safety and engineering limits.
Before achieving criticality, teams completed fuel loading and carried out multiple low-power experiments to validate system behavior.
Regulators approved each phase of this process.
In nuclear engineering terms, criticality confirms that the chain reaction sustains itself under controlled conditions.
Full power generation will follow only after months of testing, calibration, and regulatory review.
Agreeable_Sample_925 on
so glad we are ceding research and investments in renewables so the 4 coal jobs in WV that have not be replaced by automation can be saved
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India has brought a long-delayed but strategically important nuclear project to a key operational milestone.
The 500 MWe Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, Tamil Nadu, has now reached criticality, signaling that the reactor core has begun sustaining a controlled fission process.
The development places India among a small group of nations operating fast breeder reactor technology at this scale.
Indian Prime Minister Narendra Modi announced the milestone on X, framing it as a major step forward in the country’s nuclear roadmap.
“Today, India takes a defining step in its civil nuclear journey, advancing the second stage of its nuclear programme. The indigenously designed and built Prototype Fast Breeder Reactor at Kalpakkam has attained criticality.”
He added: “This advanced reactor, capable of producing more fuel than it consumes, reflects the depth of our scientific capability and the strength of our engineering enterprise. It is a decisive step towards harnessing our vast thorium reserves in the third stage of the programme. A proud moment for India. Congratulations to our scientists and engineers,” Modi said.
Built for fuel multiplication
Unlike conventional reactors, the PFBR is designed to create more fuel than it burns.
It runs on mixed oxide fuel, combining uranium-238 and plutonium-239, and uses liquid sodium as a coolant.
This configuration allows the reactor to convert fertile material into fissile fuel during operation.
Engineers consider this capability critical for sustaining long-term nuclear energy programs.The reactor was designed by the Indira Gandhi Centre for Atomic Research and built by Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI).
Both operate under India’s Department of Atomic Energy.
The project has faced delays and cost escalations since construction began in 2004.
Engineers also adapted the fuel handling system after technical issues with the original transfer mechanism, switching to an alternate approach.
Strategic shift toward thorium
India’s nuclear program follows a phased structure to manage limited uranium reserves.Fast breeder reactors anchor the second stage of this plan.
The PFBR is expected to generate fissile material that supports a future transition to thorium-based fuel cycles. India holds some of the world’s largest thorium reserves, making this shift strategically significant.
Officials see the reactor as a bridge between current uranium-based systems and a more sustainable thorium-driven future.
This transition could strengthen energy security and reduce dependence on imported nuclear fuel.
Plans for additional breeder reactors at Kalpakkam highlight India’s intent to scale this technology further.
Reaching criticality does not mean the reactor is ready to supply electricity at full capacity.
It marks the beginning of a gradual commissioning process.
Operators will now raise power levels in stages while conducting detailed performance checks.
These steps ensure the reactor operates within strict safety and engineering limits.
Before achieving criticality, teams completed fuel loading and carried out multiple low-power experiments to validate system behavior.
Regulators approved each phase of this process.
In nuclear engineering terms, criticality confirms that the chain reaction sustains itself under controlled conditions.
Full power generation will follow only after months of testing, calibration, and regulatory review.
so glad we are ceding research and investments in renewables so the 4 coal jobs in WV that have not be replaced by automation can be saved