India's most sophisticated atomic reactor, the Prototype Fast Breeder Reactor (PFBR) at Kalpakkam in Tamil Nadu, reached criticality on Monday, marking the beginning of a sustained nuclear fission chain reaction and putting the reactor one significant step closer to full operation, reported The Free Press Journal. This was a long-awaited milestone in India's civil nuclear energy programme
The 500 MWe Prototype Fast Breeder Reactor, built by BHAVINI in Tamil Nadu, marks a key advance in India's three-stage nuclear programme to tap vast thorium reserves. This helps the nation to pivot away from its limited uranium reserves.
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PM Modi congratulates
The Prime Minister congratulated the nation's scientists and engineers, calling the accomplishment a "proud moment for India". He emphasised that the reactor "reflects the depth of our scientific capability and the strength of our engineering enterprise".
This achievement, according to Modi, is a critical step towards the third phase of the nuclear programme, which intends to use India's plentiful thorium sources for long-term energy security.
"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," said PM Modi in a post on X.
Today, India takes a defining step in its civil nuclear journey, advancing the second stage of its nuclear programme.
— Narendra Modi (@narendramodi) April 6, 2026
The indigenously designed and built Prototype Fast Breeder Reactor at Kalpakkam has attained criticality.
This advanced reactor, capable of producing more fuel…
After years of development and testing, the PFBR's achievement of criticality, the point at which a sustained nuclear chain reaction starts, is a significant technical milestone. It places India in a unique category of countries that have fast breeder reactor technology in operation.
PFBR strengthens long-term energy security and self-reliance
Initally envisioned by Homi Bhabha, the PFBR's construction advances India's three-phase nuclear programme. Pressurised heavy water reactors are used in the first stage, fast breeder reactors are used in the second stage to multiply fissile material, and thorium-based reactors will be the focus of the third stage.
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This milestone, according to officials, will help minimise nuclear waste, recycle used fuel more effectively, and lessen reliance on imported uranium. Under the vision of Aatmanirbhar Bharat and Viksit Bharat, it is in line with India's larger objectives of energy self-reliance and the shift to clean energy.
