Nuclear power programme

Prelims and Mains

A pressurised heavy water reactor burns natural uranium, which is only 0.7 per cent uranium 235, because heavy water absorbs so few neutrons that the chain reaction runs without enrichment; heavy water is both moderator and coolant. The fuel sits in horizontal pressure tubes that can be refuelled while the reactor runs. India's fleet is pressurised heavy water reactors of 220, 540 and 700 MWe, and the 700 MWe design is the standard for new units, ten sanctioned in fleet mode in 2017.

• The ten 700 MW units are to take installed capacity to about 22,480 MW by 2031 to 2032.
• Expansion was held up for two decades by design changes after Fukushima, late Russian supplies at Kudankulam and difficult soil at Gorakhpur.

Prelims and Mains

The Prototype Fast Breeder Reactor at Kalpakkam is a 500 MWe sodium cooled fast reactor, about 90 per cent Indian built, run by BHAVINI.

• It burns mixed oxide fuel of uranium and plutonium with no moderator.
• A blanket of uranium 238 around the core absorbs neutrons to become plutonium 239, more than the core consumes.
• Liquid sodium carries heat well but is opaque, so the reactor is inspected by ultrasonic imaging and robots rather than by eye.
• It reached first criticality on 6 April 2026, about two decades late, and opens Stage 2 of the programme.

Prelims and Mains

A small modular reactor is a reactor of up to about 300 MWe built in a factory in modules and assembled on site, meant to cut the years and capital of a conventional plant and to fit where a large plant cannot: an old coal site, an industrial cluster, a remote grid. India is designing three: the Bharat Small Modular Reactor of 220 MWe and SMR 55 of 55 MWe, both pressurised water reactors planned for Tarapur, and a high temperature gas cooled reactor of up to 5 MWth at BARC Visakhapatnam to make hydrogen by the copper chlorine cycle.

Prelims and Mains

The Sustainable Harnessing and Advancement of Nuclear Energy for Transforming India (SHANTI) Act, 2025, notified on 21 December 2025, replaces the Atomic Energy Act, 1962 and the Civil Liability for Nuclear Damage Act, 2010. It lets private companies own and run nuclear plants under licence, makes the Atomic Energy Regulatory Board statutory, and rewrites liability: an operator's liability is graded by reactor size up to Rs 3,000 crore, the Centre's residual liability is capped at 300 million Special Drawing Rights, and equipment suppliers are exempt, removing the supplier recourse that kept foreign vendors away under the 2010 Act. A cap is what makes the risk insurable, which is the argument for it and, to its challengers, the argument against.

• Its rules are still being drafted.

Prelims and Mains

The Nuclear Energy Mission, announced in the 2025 to 2026 Budget with Rs 20,000 crore, sets the target of 100 GWe of nuclear capacity by 2047, more than ten times what runs today.

• About half is to come from indigenous pressurised heavy water reactors, a fleet heading toward 50 to 60 GW.
• The rest is to come from imported large reactors, small modular reactors and fast breeders.
• The SHANTI Act is its legal half, because the capital has to come from private and foreign investors and the liability terms decide the pace.

Prelims and Mains

Uranium from Australia is the supply India can buy under the civil nuclear cooperation agreement the two countries signed in 2015.

• Australia holds more than a quarter of the world's uranium reserves.
• It long refused to sell to countries outside the Nuclear Non-Proliferation Treaty; India is outside the treaty but was exempted by the Nuclear Suppliers Group in 2008.