Indigenous N-reactors top pick for companies in nuclear power expansion

Why in the News

The indigenous Pressurised Heavy Water Reactor (PHWR) is emerging as the preferred technology for new entrants into India’s civil nuclear power sector, as the tightly regulated strategic sector opens to private players. Representatives of the National Thermal Power Corporation (NTPC), Adani Atomic Energy and Jindal Steel said at a panel discussion at the BloombergNEF Summit in New Delhi that the existing 700 megawatt electric (MWe) PHWR is the right starting point, given established design standards, a mature domestic supply chain and an existing ecosystem of vendors. The discussion followed the release of the draft rules under the Sustainable Harnessing and Advancement of Nuclear Energy for Transforming India Act, 2025 (SHANTI Act, 2025), about a week earlier. The choice is revealing: entrants are picking the reactor with the least regulatory and supply risk rather than the one that scales fastest, and that reactor alone cannot deliver the 100 gigawatt electric target set for 2047.

What is a Pressurised Heavy Water Reactor?

1. Design: A pressurised heavy water reactor uses heavy water as both moderator and coolant, which lets it run on natural uranium without any enrichment step.
2. Why it suited India: Natural uranium fuelling matched a country with limited enrichment capacity that long stood outside international fuel supply arrangements.
3. Place in the programme: It is Stage 1 of the three stage nuclear programme designed by Homi Bhabha, producing plutonium 239 as a by product for the fast breeder stage that follows.
4. The Indian standard unit: The 700 MWe variant is the largest indigenous design in the series.

What is a Small Modular Reactor?

1. Definition: A small modular reactor (SMR) is an advanced reactor of up to 300 MWe, built as factory made modules and transported to site for assembly.
2. Use case: The smaller unit size suits captive industrial power and the replacement of retiring coal units on existing sites.

Why are private entrants choosing the 700 MWe PHWR?

1. Design certainty: The 700 MWe design is standard, approved, operational and already carries regulatory clearance, in the assessment of the business head of Adani Atomic Energy.
2. Supply chain depth: The supply chain for that design in India is almost fully indigenised, at 90 per cent to 95 per cent.
3. What the sector is short of: The two major constraints named for the sector are the availability of a robust supply chain and the lack of standardised reactor designs, and the 700 MWe unit is the one design that resolves both.
4. A second entrant agrees: Jindal Steel plans to go with 700 MWe PHWRs in its initial phase for the same reason, moving to other technologies in later phases as clarity emerges on supply chains, regulatory approvals and standardisation.

What capacity are the new entrants targeting?

1. The national target: India aims to scale domestic civil nuclear capacity to 100 gigawatt electric (GWe) by 2047.
2. Corporate targets: NTPC’s capacity target is 30 GWe, the Adani group’s is 10 GWe, and Jindal Steel’s is 18 GWe in the coming years.

What has opened the sector to private entrants?

1. Statutory replacement: The SHANTI Act, 2025 supersedes the Atomic Energy Act, 1962 and the Civil Liability for Nuclear Damage Act, 2010.
2. End of the state monopoly: It permits private and foreign firms to build, own and operate reactors, which no earlier law allowed.
3. Regulator strengthened: It gives the Atomic Energy Regulatory Board independent statutory status for safety oversight.
4. Liability rewritten: It removes statutory supplier liability and sets tiered damage caps, with a Nuclear Damage Claims Commission to adjudicate compensation after an incident.
5. What the Centre keeps: Enrichment, reprocessing and uranium and thorium exploration remain with the Union government.
6. What the draft rules cover: The rules released in August 2026 set out the framework for private participation, captive generation, licensing, safety oversight and nuclear liability.

Why will the PHWR alone not deliver 100 GWe?

1. The stated limit: PHWRs alone will not be sufficient to reach 100 GWe by 2047, in the assessment of the Adani Atomic Energy business head.
2. The intended sequence: Deploy 700 MWe PHWRs in fleet mode first, follow with pressurised water reactors (PWRs), and bring in small modular reactors at a later point.
3. Where foreign designs fit: Foreign reactor technologies and SMRs are expected to play a role only at a later stage, once the sector matures.
4. The phasing is deliberate: Later phases are contingent on clarity around supply chains, regulatory approvals and design standardisation, not on a fixed date.

What will decide whether imported designs work in India?

1. Localisation is the condition: Global reactor technologies, including PWRs and SMRs, would need to maximise localisation in India to stay commercially viable.
2. Cost sets the ceiling: Cost matters a great deal in the Indian market, and any technology has to reach a price the buyer of the electricity will commit to.
3. The buyer decides: For a project to make commercial sense the consumer has to accept the tariff, which puts affordability ahead of technology preference in the selection.

Challenges to India’s 100 GWe nuclear target

1. The heavy component vendor base is shallow: Only a handful of Indian firms can forge and supply large reactor components, so a fleet order queues behind them. Eg. Larsen and Toubro and Bharat Heavy Electricals supply most large forgings and steam generators for the domestic programme. Fix. Qualify a second tier of suppliers through advance purchase commitments tied to the sanctioned fleet order book.
2. No certified standard design outside the heavy water line: A project without a frozen design spends years in negotiation before construction. Eg. The Jaitapur project with the European Pressurised Reactor has been under negotiation since 2010 without first pour of concrete. Fix. Certify one design per technology class through the regulator before any commercial order is placed.
3. Tariff acceptance by distribution utilities: Nuclear power has to clear the price a distribution company will sign a purchase agreement at. Eg. Around 42 gigawatts of renewable capacity currently sits without a power purchase agreement on price grounds. Fix. Create a separate payment for firm, dispatchable low carbon power so the grid pays for reliability rather than for energy alone.
4. Insurance capacity is thin: Liability caps do not create the underwriting capacity a reactor needs. Eg. The India Nuclear Insurance Pool formed in 2015 carries a capacity of ₹1,500 crore. Fix. Expand the pool with reinsurance from global nuclear insurance pools, now that supplier liability has been removed.
5. Licensed operator manpower: A fleet of reactors needs certified control room staff that only one training system currently produces. Eg. Operator training runs almost entirely through the Department of Atomic Energy’s own training schools. Fix. Accredit private and university training programmes against a regulator certified curriculum and examination.

Conclusion

Private entry into nuclear power has reached the point where entrants are naming capacity targets and choosing a reactor, and all three have chosen the indigenous 700 MWe pressurised heavy water reactor over imported designs. The regulatory framework is at the draft rules stage under the SHANTI Act, 2025, released by the Department of Atomic Energy, with comments closing on 4 September 2026. Whether the 100 GWe target is reachable turns on the technologies after the first fleet, and on whether foreign designs localise enough to reach a tariff a distribution utility will sign.

“[2018, GS3, 15 marks] With growing energy needs should India keep on expanding its nuclear energy programme? Discuss the facts and fears associated with nuclear energy.”