India must decisively accelerate the integration of thorium into its civil nuclear program to insulate itself against an impending global uranium crunch and safeguard its long-term energy sovereignty, according to veteran nuclear scientist and former Atomic Energy Commission Chairman Anil Kakodkar. Delivering an address at the 6th International Climate Summit, Kakodkar warned that global uranium supply chains are facing structural tightening, with geopolitical volatility, surging international demand, and limited worldwide reserves driving market uncertainty. In this changing global landscape, India’s historical reliance on imported yellowcake threatens to constrain its domestic clean energy expansion unless the country vigorously deploys its domestic reserves of thorium.
The core vulnerability in the global nuclear equation stems from an acute mismatch between geographical mineral distribution and domestic energy requirements. While global uranium reserves are estimated at six to eight million tonnes, India’s indigenous endowment is modest, standing at roughly 0.4 million tonnes of lower-grade ore. In contrast, India holds one of the world's richest known repositories of thorium, possessing an estimated one million tonnes predominantly situated along the monazite-bearing sands of its eastern and southern shorelines. Historically, the modest availability of domestic fissile resources led India to forge civil nuclear cooperation agreements with international partners to procure overseas uranium for its civilian fleet. However, as advanced and emerging economies alike recommit to atomic energy to power base-load electricity grids and energy-intensive data centers without carbon emissions, international market pressures on uranium pricing and procurement quotas are rising sharply.
To buffer against these geopolitical and economic dependencies, Kakodkar emphasized the necessity of fast-tracking the direct utilization of thorium within India’s commercial Pressurised Heavy Water Reactors rather than treating thorium solely as a distant, third-stage objective. India’s indigenous three-stage nuclear power program—conceptualized by Homi Bhabha—envisaged PHWRs fueled by natural uranium in the first stage, followed by Plutonium-fueled Fast Breeder Reactors in the second stage to breed fissile Uranium-233 from thorium blankets, culminating in advanced thorium-based reactors in the third stage. Kakodkar pointed out that waiting decades for the second-stage fast breeder fleet to scale comprehensively before deploying substantial thorium quantities is an operational luxury India can no longer afford.
Instead, the veteran scientist advocated for incorporating thorium into current reactor configurations, notably by utilizing thorium-based oxide fuel bundles in the core of operating PHWRs alongside conventional uranium fuel. Introducing thorium into existing pressurized reactors serves multiple strategic advantages. Thorium operates with higher thermal conductivity and demonstrates enhanced fuel efficiency, allowing nuclear plants to achieve higher burnup rates while prolonging fuel bundle lifecycles. Furthermore, utilizing thorium reduces overall reliance on freshly imported uranium feed, extending the endurance of existing fuel inventories. Kakodkar underscored that this transitional roadmap allows India to build continuity in domestic fuel fabrication, gain crucial in-core operational experience, and generate essential inventories of fissile Uranium-233 well ahead of large-scale commercial breeder rollouts.
Crucial to unlocking the full potential of this resource is the modernization of nuclear fuel cycle infrastructure, particularly closed-cycle reprocessing and advanced fuel recycling technologies. Kakodkar urged Indian scientific institutions and policy planners to aggressively scale fuel recycling capabilities over the next ten to fifteen years. Unlike once-through open fuel cycles practiced in several Western nations, India’s nuclear doctrine has long been committed to a closed fuel cycle where spent fuel is reprocessed rather than discarded as permanent high-level waste. Kakodkar stressed that expanding high-capacity recycling plants is imperative to extract plutonium and unburnt uranium efficiently, thereby ensuring a continuous supply of fissile material needed to kick-start and sustain thorium-loaded reactors.
Beyond conventional heavy-water systems, Kakodkar directed attention toward next-generation atomic innovations, including Molten Salt Reactors, high-burnup advanced fuel geometries, and localized fuel enrichment capabilities. Molten salt reactor technology, which circulates liquid fluoride or chloride salts as both coolant and fuel carrier, is uniquely matched to the thorium-uranium fuel cycle. Such reactors offer passive safety attributes, can operate at atmospheric pressures without requiring massive containment structures, and operate at elevated thermodynamic temperatures suitable for industrial process heat and clean hydrogen synthesis. Kakodkar noted that establishing technological leadership across molten salt systems and Advanced Heavy Water Reactors will allow India to deploy compact, proliferation-resistant power sources that maximize the thermal yield from every kilogram of processed thorium.
The transition toward thorium also addresses critical public acceptance and regulatory imperatives concerning nuclear safety and non-proliferation. Thorium-based fuel cycles inherently produce negligible quantities of long-lived transuranic actinides, such as neptunium, americium, and curium, which dominate the long-term radiological footprint of spent uranium fuel. As a result, the radiotoxicity of spent thorium fuel decays to benign background mineral levels over centuries rather than tens of thousands of years, substantially easing the political and technical challenges associated with deep geological waste repositories. Additionally, the presence of trace Uranium-232 and its high-energy gamma-emitting daughters creates an intense, intrinsic radiation barrier that provides robust proliferation resistance against unauthorized diversion or illicit handling.
The call to prioritize thorium arrives at an inflection point as India aligns its decarbonization pledges with massive power generation mandates. With national planners targeting an expansion of nuclear capacity to 100 gigawatts by 2047 to support industrialization, urban growth, and expanding digital infrastructure, relying primarily on global uranium suppliers carries distinct strategic and economic risks. Unlocking indigenous thorium resources provides a clear pathway toward complete energy independence, shielding the domestic power grid from import dependencies and international market disruptions.
By urging policy makers to invest in immediate thorium deployment, expand fuel recycling facilities, and pioneer next-generation molten-salt architectures, Anil Kakodkar has provided a practical blueprint for national resilience. In an era where clean energy is inseparable from geopolitical autonomy, India's pathway to energy security lies under its own soil. Mobilizing the engineering and scientific infrastructure to harness this domestic resource will ensure that the country's carbon-free industrialization rests on an unshakeable, sovereign foundation.