Expert Explains: Why Thorium-Based Nuclear Power Is Crucial for India's Energy Independence
India's nuclear strategy has long been anchored in a visionary three-stage programme, designed to overcome a fundamental constraint: the nation possesses limited uranium reserves but boasts vast thorium resources. This framework aims to secure long-term energy security by ultimately transitioning to thorium-based nuclear power generation.
The Three-Stage Nuclear Programme: A Path to Self-Reliance
In the initial stage, pressurised heavy water reactors (PHWRs) utilise uranium to produce electricity while generating plutonium as a byproduct. The second stage employs fast breeder reactors (FBRs) to use this plutonium, multiplying fuel and setting the stage for the final phase. Here, thorium is converted into uranium-233, enabling sustainable and independent energy production for decades to come.
Accelerating the Transition with Imported Uranium
Former Atomic Energy Commission chairman Anil Kakodkar, now Chancellor of the Homi Bhabha National Institute, highlights a pivotal shift. With India now able to access uranium from international markets, the thermal reactor capacity, primarily PHWRs, is on a significant growth trajectory. The Nuclear Energy Mission targets 100 GWe of nuclear power capacity, with PHWRs forming the bulk. This expansion presents a unique opportunity to fast-track the thorium phase.
Kakodkar emphasises that the scale-up of PHWR capacity allows for the large-scale production of fissile uranium-233 by irradiating thorium alongside advanced fuels like HALEU (High-Assay Low-Enriched Uranium). This approach can accelerate India's journey toward energy independence without waiting for the full deployment of fast reactor capacity, which has faced delays.
Economic and Strategic Benefits of Thorium-HALEU Fuel
Integrating thorium with HALEU in PHWRs offers a win-win scenario. It not only enhances economic efficiency but also improves safety and security. Fueling costs with HALEU-thorium fuel are lower compared to using natural uranium alone, making this proposition financially viable. Moreover, PHWRs are more efficient than light water reactors (LWRs) in terms of mined uranium required per unit of power generated.
Scaling Up Capacity: Financial and Logistical Challenges
Achieving a PHWR capacity of 50-75 GWe by 2047 demands substantial financial resources and broader participation. This would require adding approximately 3 GWe annually, translating to 5-8 reactors each year, depending on unit sizes. Kakodkar advocates for involving multiple players from both public and private sectors, with the state-owned Nuclear Power Corporation of India Ltd. (NPCIL) serving as a technology provider and mentor.
The Role of Fast Reactors and Future Technologies
While PHWRs offer a practical path forward, Kakodkar stresses that fast reactor development must continue simultaneously. Breeding nuclear fuel remains essential to meet India's growing energy needs until fusion energy becomes viable. The Sustainable Harnessing and Advancement of Nuclear Energy for Transforming India (SHANTI) Act, 2025, also opens avenues for imported LWR projects, which should be viewed as complementary additions, provided they align with India's nuclear fuel cycle policies.
Conclusion: A Strategic Imperative for Viksit Bharat
In summary, leveraging imported uranium to fuel PHWRs for thorium irradiation represents a strategic imperative. It enables India to regain lost ground in its nuclear programme and switch on the thorium-uranium-233 stage much earlier than previously envisaged. As the nation aspires to become a Viksit Bharat (developed India), achieving self-sustaining thorium-based nuclear power generation is critical for securing energy independence and ensuring long-term economic growth.
