Indian Prime Minister Narendra Modi on April 6 announced the country attaining criticality of its indigenously built Prototype Fast Breeder Reactor (PFBR).
Criticality means the stage at which a nuclear reactor attains a self-sustaining chain reaction and the achievement strengthens India’s position in the advanced nuclear technology and clean energy generation, reported the state-run All India Radio.
Modi took to X in the evening of Monday, April 6, to announce the development. “Today, India takes a defining step in its civil nuclear journey, advancing the second stage of its nuclear programme,” he said.
“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.”
The existing plants in India called Pressurized Heavy Water Reactors (PHWRs) use uranium whereas PFBR burns Uranium-Plutonium mixed oxide (MOX) fuel, as reported by The Times of India.
Shifting from uranium to thorium
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India has limited uranium but vast thorium reserves and the country’s long-term strategy for its civil nuclear programme is designed keeping in mind these resources–the strategy consists of a three-stage programme aiming to gradually shift from limited uranium to abundant thorium powered energy for energy independence.
The PFBR is located in Kalpakkam in the southern Indian coastal state of Tamil Nadu and is operated by Bharatiya Nabhikiya Vidyut Nigam Ltd (BHAVINI). The latter is a government-run company under the administration of India’s Department of Atomic Energy (DAE).
“The PFBR is the forerunner of the future Fast Breeder Reactors and is expected to provide energy security to the country,” BHAVINI wrote on its website.
Dilip Sinha, a former Indian diplomat and former head of India’s UN affairs and former elected vice president of the UN Human Rights Council told Vision Times that Russia is the only country in the world with a functioning fast breeder reactor and this makes India’s achievement noteworthy.
“Attaining criticality in the crucial second stage of the 500 MW fast breeder reactor at Kalpakkam is a commendable technical achievement of India’s nuclear scientists and a milestone in eventually utilising locally available thorium in nuclear power generation,” he said in an email.
He added that it’s a peaceful use of nuclear energy. India’s nuclear energy program has been a steady contributor to the country’s electricity mix and significant expansion is planned in the coming years, according to a statement by the Indian government on April 7.
The country’s nuclear power plants generated 56,681 million Units of electricity in 2024-25 with a share of 3.1 percent of the overall generation. This is projected to reach 22.38 GW by 2031–32. India has also signed Inter-Governmental Agreements (IGAs) on Civil Nuclear Cooperation for peaceful purposes with 18 countries, according to the release.