More clear about nuclear

The long-standing joke that nuclear fusion is always 30 years away has worn thin for Pravin Kini. The medical scientist and multi-domain entrepreneur who has built or invested in multiple enterprises reckons that there are companies that are "close to fusion, just three to four years away". He visualises a future with flying cars, supersonic flights, vertical farming, waste incineration, and advanced manufacturing. These technologies require enormous amounts of energy to operate, he knows, at levels that only an energy-dense source such as nuclear can provide.

Kini's optimistic timelines — which are for the world and not for his start-up that seeks to build nuclear fusion technology — are not shared by physicists working in fusion, though they believe that the technique will eventually work and that it is a field now ready for entrepreneurship. Nuclear fusion, where two atomic nuclei are joined into a larger one with the release of energy, is hard to accomplish without spending a lot of energy to push the nuclei together. So much so that scientists so far have had to put more energy into the machine than they are able to take out of it. Progress towards an eventual commercial fusion reactor has been steady and gradual, mainly through large and expensive facilities in developed countries. In 2022, the National Ignition Facility (NIF), at the Lawrence Livermore National Laboratory in the U.S., showed that fusion can release more energy than the laser puts in, but not including the energy required to create the large infrastructure.

For fusion to occur, the hot plasma with the fusing nuclei — often at temperatures of 150 million degrees Celsius — needs to be confined to a small space without affecting the equipment around it. Private ventures are trying different and sometimes novel approaches to this confinement. "This conceptual diversity is healthy for the field," says Dinesh Aswal, Director of the Institute of Plasma Research (IPR) in Ahmedabad. "But fusion remains a frontier technology governed by physics, materials limits, and nuclear engineering, and not financial cycles."

Kini is no stranger to laser technology; one of the companies he invested in, the quantum cryptography company QNu Labs, uses single photons to securely transmit encryption keys. He chose laser fusion as his company's approach, which tries to generate fusion by compressing pellets through bombardment with high-powered lasers. Called Inertial Confinement Fusion (ICF), this is the approach taken by the Livermore facility. The alternative approach, taken by the International Thermonuclear Experimental Reactor (ITER) in southern France, involves Magnetic Confinement Fusion (MCF) of high-temperature plasma. "MCF is very capex hungry. It takes a long time with the development, there are a lot more players, while the ICF is the new kid on the block," says Kini.

India is also building large laser facilities. The Tata Institute of Fundamental Research, for instance, will have a petawatt laser facility by 2026. Kini's start-up, Gurugram-based Anubal Fusion, founded in 2024, plans to use hydrogen boron as fuel rather than deuterium-tritium, as it releases no harmful neutrons and charged alpha particles from fusion. The company is currently carrying out fusion simulations on high-performance computers and some initial fusion experiments. Kini feels that initial R&D will take three years, and engineering another seven years — and so their fusion reactor can start feeding the grid in about a decade.

In 2020, Prabhat Ranjan, a nuclear scientist and then Vice-Chancellor of Dr. D.Y. Patil Vidyapeeth, had started a fusion project, but it was shut down in 2022 as investors ran out of money. Ranjan is working on reviving the project with new investors. Some observers cite a lack of funding as one of the primary reasons fusion is still viewed as a future energy source. "Many concepts were there in fusion, but were abandoned due to the lack of money. Many private companies have picked up and are trying to revive them," says Swadesh M. Mahajan, Research Professor at The University of Texas at Austin. In the last few years, though, there has been a sudden investor interest in the technology.

According to surveys conducted by the Fusion Industry Association, a global trade association based in Washington, 53 fusion companies surveyed had raised $9.76 billion since 2022 and $2.64 billion in the 12 months preceding July 2025. On this list are $900 million series A for Pacific Fusion, based in the Bay Area, and $425 million series F for Helion, based in Everett, Washington. The Munich-based German company Marvel Fusion raised €113 million in series B funding.

In India, among the three fusion companies that recently received funding, Hyderabad-based Hylenr raised $3 million in pre-series A funding from Valour Capital and Chhattisgarh Investments in August 2025. Anubal Fusion raised $294,000 in seed funding from Speciale Invest in December 2024, while Pranos Fusion raised $417,000 from angel investor Rahul Seth in May 2025. "The growing participation of private venture capital in fusion research has accelerated innovation cycles, enabled rapid prototyping, and brought fresh engineering approaches that complement long-standing government-led programmes," says Aswal. "But the assertion that commercial fusion electricity is achievable within a decade should be interpreted cautiously."

Nevertheless, the rise in funding has been a shot in the arm for fusion researchers. These privately funded ventures are working on compact designs that are smaller, quicker and cheaper to build than the facilities at Livermore and France. But their methods are different. The U.S.-based Commonwealth Fusion Systems has built the world's strongest high-temperature superconducting magnet (20 tesla) to enable compact, efficient tokamak (magnetic confinement) reactors. Helion Energy broke ground by exceeding 100 million degrees Celsius and directly converting fusion energy into electricity. Such developments and recent scientific breakthroughs have given investors the confidence to invest in fusion start-ups.

Powerful magnets have enabled magnetic fields of 18-20 tesla — four times stronger than what older fusion magnets could provide. "It reduces the size of the reactor. The cost comes down. So, what was going to cost $20 billion now becomes $2 billion or maybe even less," says Ranjan. Advanced materials and manufacturing have changed the game, too. Many of the reactor and component designs which were difficult to manufacture earlier due to the precision needed can now be made using 3D-printing technology and glued using advanced welding. Ranjan says that the device he had planned during his PhD in the 1980s can now be developed with precision manufacturing technology. The artificial intelligence revolution enables the development of better materials for reactors, allowing for the design and testing of reactor prototypes by integrating plasma and other processes, and by analysing massive experimental datasets. Ranjan believes that these technological developments, along with funding, have brought the world closer to its goal of fusion power. "So by 2035 or before that, we expected that nuclear fusion would start feeding power into the grid, and now there are solid plans by not one but many companies," he says.

Among the various approaches to fusion, Low Energy Nuclear Reactions (LENR) or cold fusion is the most controversial. In this method, fusion occurs at 250-300°C, rather than at ultra-high temperatures. In 2023, Portugal-headquartered ENG8, based on LENR technology, completed a £2 million investment round. In India, Hylenr is taking this approach, using milligrams of hydrogen and minimal electricity in a bid to produce a 1.5X thermal output without emitting radiation or using radioactive materials. According to Hylenr's Chief Executive Officer Siddharth Durairajan, the company is expecting to develop a 1-megawatt self-sustaining nuclear power generator by 2026-end.

India's R&D centres, such as the IPR, are now also envisioning commercial reactors (India needs a national fusion energy mission: IPR Director Dinesh Aswal). IPR scientists have proposed a roadmap for India's transition from experimental fusion to commercial power via three key initiatives: a mid-sized machine SST-Bharat, which will seek to demonstrate real fusion power production in steady-state conditions, a fusion-fission reactor and a DEMO reactor targeting 250MW.

In the last century, the oil price shock of the 1970s spurred the development of nuclear power projects. At that time, economies of scale favoured large reactors over smaller ones. The last decade has seen the comeback of small modular reactors (SMRs) that produce power under 300 megawatts. Research on high-performance heat- and radiation-resistant materials, passive design systems, advanced reactor designs, and miniaturised yet efficient heat exchangers, among other areas, has progressed over the years, making small fission reactors possible as well. Modular design and factory-based manufacturing of these reactors enable large-scale production. These small-sized reactors can be easily shipped and require smaller areas of land for operation. The biggest advantage is the relatively quick deployment — in 3-4 years, rather than the 10-15 years needed for deploying large reactors. Various economies have relaxed regulations in the nuclear fission energy space, which has seen a surge in start-ups. More than 80 SMR designs are currently being developed worldwide.

India is now open to private sector participation in nuclear energy, shifting from its stand of solely government-owned nuclear power plants. The country aims to have 40-50 small modular fission reactors by 2070. To meet its immediate needs for decarbonisation of industries, India seeks to deploy the Bharat Small Reactor, whose core technology is based on the existing 220MW Pressurised Heavy Water Reactor, with 16 units operational in India. These upgraded reactors will require less land than their predecessors but provide power only to industries, rather than feeding electricity into the national grid. Private entities will provide land, cooling water, and capital, while the Nuclear Power Corporation of India Limited (NPCIL) will handle design, quality assurance, and operation and maintenance.

These reactors will be developed conventionally and not in a factory setting. The Bhabha Atomic Research Centre (BARC) and NPCIL are developing the Bharat Small Modular Reactor, which will be designed so that it can be manufactured in a factory. It will take 6-7 years for the start of a 200MW demonstration unit, and regular operation will be feasible at the end of the seventh year. These SMRs will be housed at the site of a retiring coal-based power plant.

One reason why large reactors were in the hands of the government was the high upfront installation cost. Small reactors break this barrier. "Conventional reactors have a break-even period of 10-11 years, but SMRs break even in 5-6 years," says Samyak Munot, Chief Technology Officer of the Pune-based IYNS Technology, a start-up designing SMRs.

The opening up of the sector has led nuclear scientists to set up companies. Nitendra Singh, who had worked at the ITER, a collaborative fusion research project, for five years, and Munot, who holds a PhD in nuclear engineering from BARC, together founded IYNS Tech Solutions in 2024. They have designed a 10-MW, thorium-based molten salt microreactor with a modular structure that can be transported to remote locations. The microreactor will operate underground and will have an operational life of 15 years, after which the fuel cartridge will be replaced with a new one to restart the reactor. The team chose a molten salt reactor as it is safer. It works on atmospheric pressure, unlike water-cooled reactors that operate at high pressures, thereby circumventing the risk of high-pressure explosions. As the salt is already in the molten state, there is no risk of a core meltdown. In the event of overheating, the system drains fuel into a passively cooled tank. The team hopes to have the final product ready for deployment by 2033. Apart from producing electricity, the reactor can also be used to generate heat for industries, and the excess electricity can be utilised for desalination and hydrogen production.

The developments in thorium-based nuclear technology are being closely monitored, given India's limited reserves of uranium and large reserves of thorium. "We should accelerate our Pressurised Heavy Water Reactor programme as you can load with different types of fuel, which will allow you to move towards thorium," says Anil Kakodkar, former Chairman, Atomic Energy Commission of India. In November 2025, China achieved thorium-to-uranium fuel conversion in its thorium molten salt reactor, raising hopes of thorium utilisation. However, the safe disposal of nuclear waste and limited reserves of uranium fuel in India are major concerns. Mahajan believes that both these issues can be solved with hybrid fusion-fission reactors, where neutrons emitted from fusion reactions are employed to carry out fission reactions in a surrounding blanket made of thorium or uranium.

Usual fission reactions produce actinides in nuclear waste, which have half-lives ranging from thousands to millions of years. In contrast, hybrid reactions convert these actinides into shorter-lived or stable products. The hybrid reactor also helps breed new fissile fuels, such as Uranium-233 and Plutonium-239, from abundant thorium or uranium-238 using fusion neutrons. "Getting rid of the nuclear waste will make fission more socially acceptable, and breeding of fuel will ensure that fission reactors can be fed over a fairly long period," says Mahajan.

See also:

Growing green
A green light for energy transition
Hold in store
Rare earth calling