The fusion energy programme in India has steadily evolved over the past few decades. Mention India's contributions to the…

India joined ITER in December 2005 as its seventh member and bears about 9 per cent of the cost, mostly as in-kind hardware built by Indian industry under ITER-India at the Institute for Plasma Research (IPR), Gandhinagar. This draws on a domestic fusion programme that grew from the ADITYA tokamak (1989, now upgraded as ADITYA-U) to the superconducting SST-1 (2013).

India's contributions to ITER

• The cryostat: the roughly 30-metre stainless-steel vacuum chamber enclosing the tokamak, ITER's largest single component (about 3,850 tonnes), fabricated by Larsen & Toubro.
• In-wall shielding blocks for the vacuum vessel.
• The cooling water and heat-rejection systems.
• Cryolines and cryo-distribution systems.
• Ion-cyclotron and electron-cyclotron heating power sources, power supplies for the diagnostic neutral beam, and some diagnostics.

Implications of ITER's success

ITER aims to produce 500 MW of fusion power from 50 MW of heating input (Q = 10). Proving this would show that fusion can deliver carbon-free baseload power from abundant fuel (deuterium from seawater, tritium bred from lithium), with no runaway chain reaction and little long-lived waste. It would open the way to demonstration reactors (DEMO), reduce long-run dependence on fossil fuels, and give India, as a co-owner of ITER's intellectual property, access to the full technology for its own future fusion plants. Timelines remain long—the revised schedule puts full deuterium–tritium operation in the late 2030s—so fusion will complement, not replace, renewables in the coming decades.