Nuclear fusion

Geography glossary

Also called: Fusion energy · Topic: Energy Resources of India: Conventional and Non-conventional · NCERT: Beyond NCERT

Meaning

Nuclear fusion (also called fusion energy) is the process in which two light nuclei, usually deuterium and tritium, join to form helium and a fast neutron, giving off a large amount of energy. It matters because it could one day give clean power without a runaway chain reaction. But it is not yet a commercial energy source, and electricity from it is still "a further step away".

Explanation

How it works (cause → process → result)

  • Cause: light nuclei are forced together
  • Deuterium and tritium are forms of hydrogen.

  • They must be heated to about 100 million °C so they move fast enough to join.

  • Process: the fuel becomes plasma

  • At this heat, the fuel becomes plasma (a very hot gas of charged particles).

  • Plasma at about 100 million °C is far hotter than any solid wall can withstand, so it must not touch the walls.

  • Result: energy, helium and a neutron

  • deuterium + tritium → helium + fast neutron + energy.

  • Helium is an inert gas (it does not react with other substances).

  • The Sun and other stars shine because of fusion. A fusion device on Earth must be hotter than the Sun's interior.

Magnetic confinement: the tokamak

  • Tokamak: a doughnut-shaped (toroidal) device. Powerful magnets hold the very hot plasma away from the walls.
  • Its key parts are superconducting magnets (magnets that carry current with no loss when cooled to very low temperatures) and plasma control systems.
  • SST-1 (Steady State Superconducting Tokamak) shows the parts of a tokamak:
  • 16 superconducting D-shaped toroidal field coils, with an average diameter of 1.8 m.
  • 9 superconducting poloidal field coils, plus a pair of resistive poloidal field coils.

  • Design goal: steady-state plasma for up to 1000 s.

  • Supporting skills: cryogenics (engineering at very low temperatures) and the Test Blanket Module, a wall part that captures neutrons.

Conditions and hurdles before it becomes commercial

  • The steps come one after another: confining the plasma, keeping it burning, getting more energy out than goes in (net energy), and finally sending power to the grid.
  • Cost: fusion electricity "would be expensive now".

  • Projections assume costs fall 8–20% each time total capacity doubles (the experience rate). A 2026 study says 2–8% is more likely.

  • Delays: ITER, the international fusion project, has pushed its major experiments to 2039 and added more than $5 billion to its cost.

  • Fusion–fission hybrid: a fusion device combined with a fission system. It could make electricity or burn up radioactive waste. India has told the IAEA it is interested in this idea.

Where it occurs

  • Institute for Plasma Research (IPR), Gandhinagar (Gujarat): the centre of India's fusion research. It is an aided institute of the Department of Atomic Energy (DAE).
  • India's tokamaks, in order: ADITYA → ADITYA-U → SST-1.
  • SST-1 timeline:
  • Work began in 1994, and system integration was completed in 2012.
  • First plasma came on 20 June 2013, which India reported at the 57th IAEA General Conference.

  • In 2015 it showed repeatable plasma discharges of up to about 500 ms, with plasma currents above 60 kA.

  • ITER: a multinational project with 35 countries. India is a partner and is developing a Test Blanket Module. IPR has made ITER components with Indian industry.

  • IAEA World Fusion Energy Group (WFEG): the global forum where India reports more than three decades of fusion work.
  • Private sector: 46 companies around the world are trying to make fusion commercial. Firms focused on electricity have raised $14.6 billion. India's private fusion work is centred in Bengaluru.

Don't confuse with

  • Nuclear fission: heavy nuclei such as uranium or thorium split in a chain reaction. All nuclear plants running today, including Tarapur, Kudankulam and the three-stage programme reactors, use fission. Fusion joins light nuclei and has no runaway chain reaction.
  • Fuel: fission uses uranium from places like Jaduguda and Tummalapalle, and thorium from monazite sands. Fusion uses deuterium and tritium, which are forms of hydrogen.
  • Ministry: fusion research comes under the DAE, not the Ministry of New and Renewable Energy (MNRE) or the Department of Science and Technology (DST).
  • Tokamak vs reactor: a tokamak is the magnetic machine that confines the plasma. India's tokamaks (ADITYA, SST-1) are research machines and produce no electricity.

Prelims Hooks

  • D-T fusion produces helium + a fast neutron, not a proton and not uranium fragments.
  • Fusion needs about 100 million °C, and its plasma is held by magnets in a tokamak.
  • SST-1 is at IPR, Gandhinagar (Gujarat), not at BARC Trombay. Its first plasma was on 20 June 2013.
  • SST-1 has 16 toroidal and 9 poloidal superconducting field coils. It is designed for 1000 s steady-state plasma.
  • India's tokamak order: ADITYA → ADITYA-U → SST-1. India is an ITER partner that is building a Test Blanket Module.
  • Trap: "Indian nuclear power stations generate electricity through fusion" is FALSE. All of them use fission.

Mains Points

  • Long-term energy security, not a near-term fix:
  • Fusion is expensive, and ITER's major experiments are delayed to 2039.
  • So it cannot help India reach 500 GW of non-fossil capacity by 2030. Solar, wind, hydel and fission must carry that load.

  • Fusion is best treated as research funding for the decades after that, and it fits the net-zero 2070 horizon.

  • Spin-off skills and the hybrid path:

  • SST-1 and ITER work have built Indian skill in superconducting magnets, cryogenics and plasma control.
  • Indian industry has solved "first-of-a-kind" engineering problems through ITER contracts.

  • A fusion–fission hybrid could burn radioactive waste from India's fission programme.

  • Regulatory gap (GS-III):

  • The SHANTI Act, 2025 replaced the Atomic Energy Act, 1962 and the CLND Act, 2010.
    • It allows private licences and gives the AERB statutory status (it is set up by law).
    • Its liability bands run from ₹100 crore to ₹3,000 crore, depending on the type of facility.
  • But the law is written for fission, and it does not say how a tokamak is classified.
  • In 2021 the US began a separate set of fusion rules instead of applying its fission rules. India could follow this model, with its own rules for tritium handling and a lower liability band.

Recent developments

  • 2007 – Cabinet approves India's ITER funding: The Union Cabinet approved India's ITER participation at a base cost (the first approved budget, before any later revision) of Rs 2,500 crore. It also set up an Empowered Board under IPR, Gandhinagar, to run the project within that amount. This matters because the money was approved when experiments were expected around 2025. With the date now pushed further, the cost to India is likely to rise.

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