A Historic Moment, Decades in the Making
A silent yet tremendous event unfolded on 6 April 2026 at the Indira Gandhi Centre for Atomic Research in Kalpakkam, Tamil Nadu. The PFBR, India’s indigenously designed 500 MWe Prototype Fast Breeder Reactor, achieved first criticality, marking the successful initiation of a self-sustaining nuclear chain reaction in a technology that only one other nation in the world, Russia, has managed to commercialize at scale.
This did not come as a surprise to those who have been following India’s nuclear programme closely. It was a result of five decades of sustained scientific investment, institutional patience, and strategic vision. The criticality of the PFBR is not just a technological milestone. The three-stage programme of India was modeled on the resource reality of the country: limited uranium, but one of the largest thorium endowments in the world.
Stage II Unlocked: The Three-Stage Nuclear Vision of India
The nuclear programme of India was designed in the 1950s by Dr Homi Bhabha with a vision that was, frankly, extraordinary at that time. Understanding that India possessed limited reserves of uranium, but one of the largest thorium deposits in the world – estimated at more than 300,000 tonnes, or about 25% of the global reserves, Bhabha developed a three-stage roadmap to achieve long-run energy self-sufficiency.
Stage I, which is now mostly complete, involves Pressurised Heavy Water Reactors (PHWRs) fuelled by natural uranium. India has steadily expanded this fleet, most recently commissioning two indigenously designed 700 MWe PHWRs at Kakrapar (Units 3 and 4), each with capacity factors exceeding 90% among the highest in the world for that reactor class.
Stage ll, now unlocked by the PFBR, uses the fast neutron reactors to breed plutonium in Stage I reactors. This plutonium can be then recycled as fresh fuel- dramatically extending the energy yield from each kilogram of uranium and creating the fissile feedstock of the critical next transition.
Stage lll, is the ultimate destination, thorium-fuelled reactors that will use the large domestic reserves in India to power the nation for centuries. The PFBR is the essential bridge to that future. The fact that India is now the second nation after Russia to successfully operate a commercial-scale fast breeder reactor places it in a truly elite technological tier.
What They Spent Billions to Abandon
The achievement of India looks even more remarkable when compared to the global graveyard of the fast breeder ambitions.
The EBR-II experimental reactor was run by the United States but ultimately shuttered its entire fast breeder programme. France’s Superphénix, once the world’s largest fast reactor was decommissioned in 1998 following years of operational problems and political pressure. The Monju reactor in Japan was plagued by sodium coolant leakages and regulatory failures and was officially abandoned in 2016 after absorbing nearly ¥1 trillion of government funds. Germany, the United Kingdom, and others similarly retreated.
These were not minor programmes. They collectively represented hundreds of billions of dollars in investment and the involvement of the world’s most sophisticated nuclear engineering institutes. None of them succeeded in commercialisation.
India persisted. The PFBR programme survived through funding restrictions, international sanctions after the 1998 Pokhran tests, supply-chain constraints, and several construction delays, by the Department of Atomic Energy and BHAVINI (Bharatiya Nabhikiya Vidyut Nigam Limited). It is a rare demonstration of long-term strategic execution in an area where almost every other democracy faltered.
The investor’s lesson is not that India was fortunate. It is that India was disciplined.
Why This is Important to India as a Nation
The strategic imperatives behind the nuclear expansion are as powerful as the technological achievement. Today, India imports over 85% of its crude oil and a significant portion of its natural gas, leaving its energy economy acutely exposed to geopolitical volatility and currency risk. Each rupee spent on uranium and thorium domestically is a rupee that stays in the country. Each gigawatt of nuclear baseload energy displaces fossil fuel imports, supports the current account, and strengthens macroeconomic resilience.
The strategic appeal is amplified by fuel security: India’s thorium reserves are among the largest globally while uranium is limited. The PFBR is not merely a reactor, it is a bridge to fuel cycle that, in principle, can reduce the import reliance on imports over time and support the long-duration energy security that a rapidly expanding economy needs. Nuclear energy occupies a valuable position in a system that needs power electrification, industrialization, and support data infrastructure while still honoring the net-zero-by-2070 target.
Policy Architecture is now in Place
The Union Budget 2025-26 marked a clear change in policy ambition. The government declared the Nuclear Energy Mission, which dedicated ₹20,000 crore towards the development of Small Modular Reactors (SMRs) and associated research infrastructure. More importantly, the suggested SHANTI Bill- Strategic and Holistic Advancement of Nuclear Technology in India are designed to open the sector to private and foreign participation for the first time.
It is a structural inflexion point. For decades, India’s nuclear industry was exclusively preserved by the state-owned entities. The proposed legislative changes will enable the involvement of the private Indian conglomerates and foreign technology partners to invest in nuclear power generation, manufacturing, and services initiating a wave of capital deployment that the public sector alone cannot sustain at the scale required.
The Road Ahead
The PFBR is projected to commence full commercial operations in late 2026 or early 2027, after the completion of fuel loading, regulatory clearances, and power ascension testing. This will formally establish India’s Stage II capability and provide the operational data required to design and scale the next generation of fast reactors.
Beyond the PFBR, the pipeline includes ten additional 700 MWe PHWRs in different phases of construction and approval, the Bharat Small Reactor programme targeting 2033 commissioning, and ongoing discussions with international partners including Westinghouse, EDF, and Rosatom- for large-scale reactor deployments under the civil nuclear cooperation framework.
Execution risks are real. Nuclear projects are capital intensive, technically complicated and prone to long gestation periods. The SHANTI Bill regulatory reform needs parliamentary passage and implementation bandwidth. The supply chain localisation at the scale needed for 100 GW will demand sustained industrial policy. These are no trivial challenges.
However, the enabling conditions- high policy intent, an established scientific foundation, legislative reform underway and private sector appetite are more aligned today than at any point in India’s nuclear history.
In conclusion of this article, Nuclear power in India is shifting towards strategic ambition to industrial scale, state-only execution to a more distributed model, and from a fuel-constrained architecture to one that can eventually leverage thorium. The nuclear resurgence in India is a clean-energy narrative, an Atmanirbhar Bharat story, and, increasingly, an infrastructure and industrial-capital story as well. The right approach is not to chase the moment, but to study the ecosystem carefully and own the themes that can compound alongside the country’s energy transition.