Revision summary
Fusion joins light nuclei and could, in theory, give large low-carbon power without a fission-style chain reaction. ITER in France is the global experiment; India is a member supplying about a tenth of in-kind components such as the cryostat and cooling systems. Indian tokamaks and the Institute for Plasma Research built the domestic base. ITER success would prove the physics, not deliver cheap power in 2030. The climate implication is a possible later baseload, beside renewables that are needed now.
Model answer
Copper italics in this answer — like this — are the key facts. Each one is unpacked in the Facts & figures rail.
Introduction
Nuclear fusion is the process in which light atomic nuclei combine under extreme conditions to release energy, as occurs in the Sun. India has developed indigenous fusion capabilities through the Institute for Plasma Research (IPR) and contributes to the international fusion effort through the International Thermonuclear Experimental Reactor (ITER) in France.
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India's Contributions to ITER
India is a full ITER partner and contributes through hardware, technological expertise and scientific manpower.
- Cryostat: India has supplied the world's largest stainless-steel cryostat, manufactured by Larsen & Toubro, which provides the vacuum and thermal environment around the ITER tokamak.
- Cooling Water System: India contributes the cooling-water systems required to remove heat from critical ITER components.
- In-wall shielding: Indian industry supplies shielding components that protect reactor structures from high-energy neutrons produced during fusion.
- Cryogenic systems: India contributes cryolines and associated cryogenic infrastructure required for superconducting magnets.
- Power supplies: Indian industry supplies specialised power-supply systems for major ITER components.
- Scientific and technical expertise: Indian scientists and engineers contribute expertise in plasma physics, superconducting systems, materials and reactor engineering, strengthening India's domestic fusion capabilities.
Implications of ITER's Success for Global Energy
- Clean low-carbon energy: Successful fusion could provide large-scale electricity with very low greenhouse-gas emissions, supporting global decarbonisation.
- Abundant fuel potential: Deuterium, one of the principal fusion fuels, is abundantly available in seawater, offering a potentially large long-term energy resource.
- Reliable power: Commercial fusion could eventually provide firm, continuous electricity and complement intermittent renewable sources such as solar and wind.
- Greater energy security: Widespread fusion deployment could reduce dependence on geographically concentrated fossil-fuel resources and exposure to oil and gas price shocks.
- Lower accident potential: Fusion does not depend on a self-sustaining nuclear chain reaction; disruption of the required plasma conditions causes the fusion process to stop.
- Transformation of energy geopolitics: Successful commercialisation could reduce the strategic importance of fossil-fuel reserves and reshape global energy relations.
- Long-term technological pathway: ITER success would demonstrate the feasibility of sustained fusion but would not immediately mean commercial fusion power; further advances in materials, tritium management, engineering and cost reduction would still be necessary.
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Conclusion
India's ITER participation combines advanced hardware, industrial capability and scientific expertise. A successful ITER would establish a technological foundation for clean, reliable and potentially abundant fusion energy, with long-term implications for global energy security and climate mitigation.
Quick related
Students also ask
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How can India achieve energy independence through clean technology by 2047? How can biotechnology play a crucial role in this endeavour?
Next question on this syllabus topic (2025 · Q6). View answer →
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Is fusion the same as the hydrogen bomb?
The physics family is related. A reactor is a controlled burn, not a runaway weapon.
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Should India wait for ITER before building solar?
No. ITER is a research timeline. Solar is a this-decade grid timeline.
Same topic · past papers
UPSC has asked this before
These previous-year questions sit on the same topic. Open one to practise the earlier ask.
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2019 · Q5 · GS III · 10 marks
How was India benefitted from the contributions of Sir M. Visvesvaraya and Dr. M. S. Swaminathan in the fields of water engineering and agricultural science respectively? -
2023 · Q4 · GS III · 10 marks
State the objectives and measures of land reforms in India. Discuss how land ceiling policy on landholding can be considered as an effective reform under economic criteria.
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Q6 · UPSC Mains 2025 · GS III · 10 marks · Solution
How can India achieve energy independence through clean technology by 2047? How can biotechnology play a crucial role in this endeavour?
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India still imports most of its crude, so 2047 independence means much lower import intensity, not a sealed border. Clean electricity from solar, wind, storage and nuclear, plus green hydrogen and efficiency, are the main path. Electric mobility cuts oil only if the grid is cleaner. Biotechnology helps through biogas, second-generation ethanol from residue, industrial enzymes and less energy-intensive farming. Fuel-from-food is a poor version of that biotech role.