By: Vishal Manve
When India’s Prototype Fast Breeder Reactor (PFBR) at Kalpakkam achieved first criticality in April 2026, it marked more than a technical milestone in the country’s long-delayed nuclear program. Three months earlier, the board of an Indian public sector undertaking NTPC Limited approved a minority equity stake in Chicago-based Clean Core Thorium Energy, only the second American company in nearly two decades to receive U.S. Department of Energy authorization for nuclear technology transfer to India. Viewed separately, these developments might appear routine. Taken together, they reveal something more consequential: India’s nuclear future is increasingly unfolding along two parallel tracks, one rooted in indigenous strategic capability and the other in internationally integrated commercial innovation. For Washington, understanding and engaging both will be central to the next phase of U.S.–India civil nuclear cooperation.
The scale of India’s ambitions gives this moment strategic weight. India currently operates roughly 8.7 GW of nuclear capacity, contributing around 3% of national electricity generation. Under its Viksit Bharat vision, the country aims to expand this to 100 GW by 2047, with an interim target of 22 GW by 2031–32. Even partial realization would place India among the world’s largest nuclear growth markets over the next two decades. Yet India’s pathway to that future is not singular. It combines long-term investments in advanced reactors and fuel-cycle capabilities with emerging efforts to attract capital, technology, and international partnerships.
The PFBR sits at the heart of India’s indigenous strategy. The 500 MWe sodium-cooled, pool-type reactor, designed by the Indira Gandhi Centre for Atomic Research and Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI), represents a level of technical sophistication possessed by only a small group of countries. Once it begins generating electricity, projected later this year, India will become only the second country after Russia to operate a commercial-scale fast breeder reactor. The project’s journey has been difficult. Costs rose substantially from original estimates, and criticality arrived sixteen years behind schedule. But judging PFBR solely through cost overruns or delays risks missing its larger strategic significance. Western countries largely abandoned commercial breeder development decades ago. India did not. PFBR places India within a small cohort of states, including Russia and China, capable of operating fast neutron systems while advancing the long-term thorium-based fuel cycle that underpins India’s nuclear strategy.
At the same time, a parallel and potentially complementary pathway is emerging through fuel innovation and commercial collaboration. Clean Core’s patented ANEEL fuel, a blend of thorium and high-assay low-enriched uranium (HALEU), is designed for use in India’s existing fleet of pressurized heavy water reactors, allowing greater thorium utilization without waiting for breeder deployment to mature. Former Department of Atomic Energy chairman Anil Kakodkar has pointed precisely to this possibility: advancing India’s thorium trajectory through existing reactor infrastructure while breeder technology evolves. The structure of the Clean Core partnership is equally notable. The company is headquartered in the United States and licensed by the Department of Energy, while its leadership, investors, and strategic alignment are deeply connected to Indian priorities. NTPC’s interest adds another layer, bringing India’s largest power producer into what could become a commercially meaningful U.S.–India nuclear venture.
This evolving landscape has been shaped by important regulatory changes. The Sustainable Harnessing and Advancement of Nuclear Energy for Transforming India (SHANTI) Act, enacted in December 2025, repealed both the Atomic Energy Act of 1962 and the Civil Liability for Nuclear Damage Act of 2010. For years, supplier liability provisions under the 2010 law, particularly Section 17(b), diverged from international practice and discouraged American participation in India’s nuclear market. The new framework aligns India more closely with the International Atomic Energy Agency (IAEA) Convention on Supplementary Compensation by capping operator liability and reducing supplier exposure. It also opens space for private participation in areas such as plant ownership and fuel fabrication while maintaining sovereign control over enrichment, heavy water production, and spent fuel management.
These changes are already intersecting with American policy decisions. In 2025, the U.S. Department of Energy granted 10 CFR Part 810 authorization to Holtec International for sharing small modular reactor technology with Indian partners including Larsen & Toubro and Tata Consulting Engineers. Clean Core subsequently received a comparable authorization. Together with SHANTI, these steps represent the most concrete commercial opening in U.S.–India civil nuclear cooperation since the 2008 agreement. Importantly, they also suggest that future collaboration may not begin with large reactor projects alone. Fuel systems, components, advanced materials, engineering services, and modular technologies may offer more practical near term entry points.
For Washington, this creates both an opportunity and a policy test. American firms have long struggled to translate the landmark 2008 civil nuclear agreement into commercially viable projects. India’s emerging two track strategy offers a different lens. Cooperation need not hinge exclusively on utility scale reactor deals. A more durable framework could emerge by engaging across both pillars of India’s nuclear trajectory: indigenous breeder and fuel-cycle development on one side, and commercially oriented partnerships in fuels, components, and advanced technologies on the other.
India’s nuclear future is no longer defined by a single pathway. PFBR and the NTPC–Clean Core partnership reflects a broader strategic posture that blends self-reliance with international integration. For U.S. policymakers shaping Indo-Pacific energy strategy, sustained engagement across both tracks may ultimately determine whether the next chapter of U.S.–India civil nuclear cooperation moves beyond the promise of the 2008 deal toward a meaningful long-term partnership.
Vishal Manve is an energy transition and technology policy researcher based at the Lamont-Doherty Earth Observatory of Columbia University.