India’s Strategic Roadmap for Nuclear Fusion Energy Development

Introduction

India has embarked on a comprehensive and ambitious strategy to develop nuclear fusion energy as a cornerstone of its long-term energy security and climate goals.

Building on decades of domestic research and international collaboration, the nation is positioning itself to transition from experimental fusion projects to commercial-scale deployment by the latter half of the 21st century.

This article synthesizes India’s multifaceted approach, which combines participation in global initiatives like ITER, advancements in indigenous fusion technology, policy reforms, and industrial partnerships.

International Collaboration

The ITER Partnership and Its Implications

India’s involvement in the International Thermonuclear Experimental Reactor (ITER) represents a cornerstone of its fusion strategy.

As one of seven primary partners in the €22 billion project, India contributes 9% of the hardware components—equivalent to ₹17,500 crore—while securing full intellectual property rights to fusion technology.

This collaboration has enabled Indian industries to develop cutting-edge capabilities, exemplified by Larsen & Toubro’s (L&T) fabrication of the 3,800-tonne cryostat, the largest vacuum vessel ever constructed, which forms the heart of the ITER reactor.

The cryostat, designed and assembled in Gujarat, underscores India’s industrial prowess in precision engineering for fusion applications.

Beyond hardware contributions, ITER serves as a critical training ground for India’s scientific workforce.

The Institute for Plasma Research (IPR) in Gandhinagar, which oversees India’s ITER commitments, has leveraged this partnership to advance its expertise in superconducting magnets, cryogenics, and plasma diagnostics.

These competencies are directly transferable to India’s domestic fusion program, ensuring that knowledge gained from ITER informs the design of future indigenous reactors.

Domestic Fusion Research

From Tokamaks to Hybrid Systems

India’s domestic fusion program, initiated in the 1980s with the Aditya tokamak, has evolved into a robust R&D ecosystem.

The upgraded Aditya-U and the Steady-State Superconducting Tokamak (SST-1) at IPR routinely conduct experiments to optimize plasma confinement and stability—key challenges for sustained fusion reactions.

These projects have yielded insights into high-heat-flux materials and tritium breeding blankets, technologies essential for managing the extreme conditions within fusion reactors.

A distinctive feature of India’s approach is its exploration of fusion-fission hybrid reactors.

By integrating fusion neutron sources with subcritical fission assemblies, these systems aim to transmute nuclear waste and breed fissile materials like U-233 from thorium.

This hybrid model addresses two challenges simultaneously: reducing radioactive waste from existing nuclear plants and bridging the gap until pure fusion power becomes viable.

IPR scientists estimate that such hybrids could enter pilot testing by the 2040s, leveraging India’s extensive thorium reserves and expertise in fast breeder reactors.

Policy Frameworks and Funding Commitments

The Union Budget 2025 marked a watershed moment for India’s nuclear ambitions, allocating ₹20,000 crore ($2.4 billion) to accelerate the deployment of Small Modular Reactors (SMRs) and fusion research.

While SMRs primarily utilize fission, this funding signals the government’s intent to create a synergistic ecosystem where advancements in materials science and reactor engineering benefit both fission and fusion technologies.

Notably, the budget explicitly endorsed privatizing segments of the nuclear sector, enabling partnerships between the Department of Atomic Energy (DAE) and firms like L&T and Bharat Heavy Electricals Limited (BHEL).

Concurrently, India is revising its Atomic Energy Act of 1962 to permit private and foreign investments in nuclear projects—a move that could unlock capital for fusion startups and infrastructure.

The NITI Aayog, a government think tank, has recommended establishing a Fusion Energy Mission under the “Viksit Bharat 2047” vision, targeting 100 GW of nuclear capacity (including fusion hybrids) by 2047.

Industrial Mobilization and Technological Spin-Offs

Indian industry has emerged as a linchpin in the fusion supply chain.

Beyond L&T’s cryostat, companies such as Godrej Aerospace and Avantel Limited contribute precision components for ITER’s toroidal field coils and diagnostic systems.

These contracts have spurred innovations in high-vacuum welding and radiation-resistant alloys, technologies now being repurposed for India’s Prototype Fast Breeder Reactor (PFBR) program.

The PFBR, which began fuel loading in 2024, serves as a testbed for materials destined for future fusion reactors, particularly those capable of withstanding 14 MeV neutron fluxes.

The private sector’s role extends to R&D: startups like FusionGrid Energy and Bharat Fusion Systems are developing compact stellarators and advanced tritium extraction systems with support from the DAE’s Advanced Technology Vertical.

This public-private model mirrors strategies employed by fusion leaders like the U.S. and U.K., ensuring that India remains competitive in the global race for commercial fusion.

Long-Term Vision

From Experimental Reactors to a Fusion-Powered Grid

India’s fusion roadmap delineates three phases leading to commercialization:

ITER Participation (2025–2035)

Complete in-kind contributions to ITER, achieve first plasma in 2035, and validate reactor-scale technologies like deuterium-tritium fueling systems.

DEMO Reactor Development (2035–2060)

Design and construct a 500 MWe Indian Demonstration Reactor (INDRA) integrating lessons from ITER and hybrid experiments.

Key objectives include achieving a tritium breeding ratio >1.1 and continuous operation exceeding 6 months.

Commercial Deployment (Post-2060)

Commission fusion plants capable of baseload power generation, targeting 50 GW of fusion capacity by 2100.

This phase will prioritize thorium-based fuel cycles to align with India’s three-stage nuclear strategy.

Critically, this timeline dovetails with India’s Net Zero by 2070 pledge.

Fusion is projected to offset 750 million tonnes of CO2 annually by 2100, complementing renewable energy and conventional nuclear.

Challenges and Risk Mitigation

Despite progress, India faces hurdles in scaling fusion technology.

Tritium scarcity remains a concern, as the country lacks sufficient reserves for large-scale deployment.

IPR is addressing this by prototyping lithium-lead breeder blankets capable of generating tritium in situ.

Additionally, the high capital costs of fusion infrastructure—estimated at ₹50,000 crore ($6 billion) per GW—necessitate international financing mechanisms.

India is advocating for a Global Fusion Fund under the IAEA to pool resources among ITER members.

Conclusion

Fusion as a Pillar of Energy Atmanirbharta

India’s fusion ambitions reflect a strategic calculus to achieve energy self-reliance while mitigating climate risks.

By synergizing ITER collaborations, domestic R&D, policy reforms, and industrial mobilization, the nation is laying the groundwork for a fusion-powered future.

While technical and economic challenges persist, India’s phased approach—prioritizing hybrid systems and incremental technology maturation—positions it to capitalize on fusion’s transformative potential.

As Prime Minister Modi noted during the PFBR fuel-loading ceremony, “Fusion is not merely an energy source; it is the foundation of Viksit Bharat’s second green revolution”.

With sustained investment and international cooperation, India could emerge as a global fusion leader by the centenary of its independence in 2047.