India has commissioned a pilot hydrogen production facility that uses heat from a nuclear reactor, rather than conventional grid electricity, to generate clean hydrogen.The facility, set up by the Department of Atomic Energy at the Indira Gandhi Centre for Atomic Research (IGCAR) in Kalpakkam, Tamil Nadu, uses high-temperature heat from the Fast Breeder Test Reactor to split water into hydrogen and oxygen through an indigenously developed process, marking a significant step in nuclear-assisted clean energy research.
What is the copper-chlorine thermochemical cycle?
To understand the significance of the development, it is important to note how hydrogen is typically produced. The most widely used method today is steam methane reforming, which relies on natural gas and high heat to extract hydrogen from fossil fuels, resulting in what is known as grey hydrogen with substantial carbon emissions.A cleaner alternative is electrolysis, which uses electricity to split water into hydrogen and oxygen. When powered by renewable energy sources such as solar or wind, this process produces green hydrogen with no direct carbon emissions.However, scientists have also been developing a third pathway for decades, the Copper-Chlorine (Cu–Cl) thermochemical cycle. Developed indigenously by the Bhabha Atomic Research Centre (BARC) in Mumbai, the process does not rely on electricity as the primary input. Instead, it uses high-temperature heat, such as that generated by a nuclear reactor, to drive a series of chemical reactions involving copper and chlorine compounds that are continuously recycled within the system.Through this closed-loop cycle, water is split into hydrogen and oxygen, while the copper and chlorine compounds are reused. The process does not involve the burning of fossil fuels and produces no direct carbon dioxide emissions.
A faster, cleaner way to make hydrogen
Scientists are particularly encouraged by the development not only because it eliminates carbon emissions, but also due to its potential efficiency advantages. While electrolysis can also produce clean hydrogen when powered by renewable energy, it involves multiple energy conversion steps, each of which leads to losses.In contrast, the Copper-Chlorine (Cu–Cl) thermochemical cycle allows heat to be directly used to drive chemical reactions, bypassing the need to first convert heat into electricity. By eliminating this intermediate step, the process has the potential to extract more hydrogen from the same amount of energy input.The cycle operates at around 500°C, a relatively moderate temperature compared to other thermochemical methods that require much higher heat levels and are therefore more challenging to deploy at scale. Fast breeder reactors, such as the Fast Breeder Test Reactor (FBTR) at Kalpakkam, are capable of supplying heat in this temperature range, making the approach more technically feasible for real-world application.
Kalpakkam reactor key to new hydrogen technology demonstrator
The Fast Breeder Test Reactor (FBTR) at the Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, has been a key pillar of India’s nuclear research programme for decades. It is a sodium-cooled fast reactor that uses liquid sodium as a coolant instead of water, enabling it to operate at higher temperatures than conventional reactors. This makes it particularly suitable for supplying the process heat required for the Copper-Chlorine (Cu–Cl) cycle.The FBTR has also contributed significantly to the development of fuels, materials and related technologies under India’s three-stage nuclear power programme, which includes the 500 MWe Prototype Fast Breeder Reactor, currently under advanced development at Kalpakkam, as its flagship second stage.According to the Department of Atomic Energy, the newly inaugurated hydrogen facility is a technology demonstrator designed to validate the process under real operating conditions, generate performance data, and support further optimisation before potential scale-up. The project is the result of a joint effort between BARC and IGCAR, involving years of research, engineering design, fabrication and testing prior to commissioning.
What is ‘pink hydrogen’ and why does it matter?
The hydrogen produced at the facility is often referred to as “pink hydrogen,” a term used for hydrogen generated using nuclear energy as the primary source, with no direct carbon emissions. It is classified alongside green hydrogen, produced from renewable energy, and blue hydrogen, derived from natural gas with carbon capture, as one of the cleaner pathways for hydrogen production.What distinguishes pink hydrogen, and what the new Cu–Cl facility demonstrates, is the potential of nuclear energy to provide a continuous, weather-independent source of clean hydrogen. Unlike solar and wind power, which are intermittent and dependent on weather conditions, nuclear reactors operate round the clock.As a result, a nuclear heat-based hydrogen system can produce hydrogen 24/7 without interruption, offering a stable and reliable supply. This consistency is particularly significant for industries that require large-scale, continuous hydrogen availability.
Powering heavy industry with hydrogen
Industries that depend heavily on hydrogen today, including fertiliser production, petroleum refining, and steel manufacturing, are also among India’s largest sources of carbon emissions. Fertiliser plants alone use large volumes of hydrogen to produce ammonia, with most of this hydrogen currently derived from natural gas.If nuclear heat-based hydrogen production can be scaled up at competitive costs, it could provide these sectors with a viable pathway to decarbonisation without requiring major changes to their core industrial processes.Hydrogen is also being explored as a potential fuel for heavy transport, including trucks, ships, and possibly trains. In these applications, hydrogen offers an advantage over batteries due to its higher energy density per kilogram, making it more suitable for long-distance and heavy-load operations where battery weight becomes a limitation.A steady, low-carbon supply of hydrogen produced continuously using nuclear energy could therefore play a significant role in accelerating India’s broader decarbonisation efforts.
From power to hydrogen: India’s nuclear vision grows
India’s nuclear power programme has long been guided by a long-term vision that extends beyond electricity generation. Conceived by Dr Homi Bhabha, the three-stage programme aims to ultimately utilise the country’s abundant thorium reserves as fuel.The integration of hydrogen production into this framework further expands the role of nuclear energy, moving it beyond power generation into clean fuel production. According to Ajit Kumar Mohanty, Secretary of the Department of Atomic Energy (DAE), the development reflects India’s growing capabilities in advanced nuclear technologies and demonstrates that nuclear energy’s contribution to a sustainable future can extend well beyond conventional reactor applications.
