India has taken a significant step in expanding the role of nuclear energy beyond electricity generation with the demonstration of a nuclear-assisted hydrogen production system at Kalpakkam, opening a new pathway for supplying clean energy to industrial sectors that are difficult to decarbonise.
The project explores the use of nuclear process heat to produce hydrogen, offering an alternative to conventional green hydrogen production that depends heavily on renewable electricity, The Economic Times reported..
While electricity remains central to energy transition efforts, industries such as steel, fertilisers, petrochemicals, refining and shipping require large volumes of industrial heat and feedstock that are difficult to meet through renewable power alone. Hydrogen has increasingly emerged as a preferred solution for reducing emissions in these sectors.
Unlike traditional electrolysis, which relies entirely on electricity generated from renewable sources, the Kalpakkam demonstration uses heat produced by the Fast Breeder Test Reactor to drive thermochemical reactions that split water into hydrogen and oxygen.
The project employs the Copper-Chlorine (Cu-Cl) thermochemical cycle, a hybrid process that combines thermochemical and electrochemical stages. Most of the energy requirement is supplied through reactor heat, while only a relatively small amount of electricity is used during the electrochemical phase.
Operating at a maximum temperature of around 530°C, the Cu-Cl cycle requires substantially lower temperatures than several competing thermochemical technologies and is being positioned as one of the more practical nuclear-assisted hydrogen approaches under development.
According to the project details, recyclable copper and chlorine compounds are circulated in a closed-loop system that separates water into hydrogen and oxygen while minimising external chemical consumption.
One of the key advantages highlighted is lower electricity demand compared with conventional electrolysis. The electrochemical process operates at relatively low voltage levels, reducing overall power consumption.
The overall efficiency of the Cu-Cl cycle has been estimated at slightly above 43 per cent, excluding additional gains that could come from recovering and utilising waste heat. Since water is the primary input and hydrogen and oxygen are the final outputs, the process produces minimal carbon emissions when powered by nuclear heat.
The Copper-Chlorine process was developed by the Bhabha Atomic Research Centre (BARC), while integration with the reactor system was carried out jointly by BARC and the Indira Gandhi Centre for Atomic Research (IGCAR).
The development adds a new dimension to India’s National Green Hydrogen Mission, which has largely focused on hydrogen produced through renewable-energy-powered electrolysers.
Supporters of the technology argue that nuclear energy offers a major operational advantage because reactors can provide uninterrupted heat and electricity throughout the year, potentially improving hydrogen production economics through higher utilisation rates.
The implications extend beyond hydrogen production. Future advanced reactor systems could evolve into integrated energy hubs capable of producing electricity, hydrogen, industrial steam, desalinated water and synthetic fuels from a single facility.
During the inauguration, Department of Atomic Energy Secretary and Atomic Energy Commission Chairman Dr Ajit Kumar Mohanty said combining nuclear energy with emerging clean technologies such as hydrogen production represents an important pathway toward a sustainable energy future.
The project also aligns with India’s broader fast reactor strategy. The country’s 500 MWe Prototype Fast Breeder Reactor achieved first criticality on April 6, 2026, marking progress in the second stage of India’s long-term nuclear programme, although commercial generation has not yet begun.
By connecting hydrogen production with the Fast Breeder Test Reactor, India is demonstrating how advanced nuclear technologies can support industrial applications beyond electricity.
IGCAR Director Sreekumar G. Pillai described the development as the outcome of decades of operational experience and technological capability built through India’s fast breeder reactor programme.
Globally, thermochemical hydrogen production has remained largely at the research stage because of engineering complexity, material durability challenges and difficulties in scaling.
What distinguishes the Kalpakkam project is the integration of the Copper-Chlorine cycle with an operating nuclear facility, creating an opportunity to generate real-world operating data and evaluate long-term performance under continuous conditions.
Researchers acknowledge that several challenges remain before commercial deployment, including efficient heat transfer, management of corrosive process environments, economic viability, integration of chemical and nuclear systems and development of regulatory frameworks.
Cost competitiveness will remain a decisive factor, as nuclear-assisted hydrogen will ultimately compete against renewable-powered electrolysis and fossil-based hydrogen production with carbon capture.
If future operational results demonstrate durability, efficiency and commercial viability, the Kalpakkam project could mark an important step toward a new industrial model where nuclear facilities serve as integrated clean energy production centres rather than solely electricity generators.
