On 28 August 2026, PIB issued two backgrounders — Nuclear Energy in India: Applications, Safety, and Preparedness and Nuclear Energy Technology in India: Sustainable and Self-Reliant Future. Together they are the most complete official statement of the programme available this year, and they arrive at a moment when the legal foundations of Indian nuclear power have just been rewritten.
The position today: 24 operating reactors across seven sites, total installed capacity 8.78 GW; nine reactors under construction totalling 7.5 GW; preparations for 10 more units. The Nuclear Energy Mission for Viksit Bharat targets 100 GW by 2047, and the Union Budget 2025-26 allocated ₹20,000 crore for indigenous Small Modular Reactors.
Hold those numbers next to each other, because the gap is the story: 8.78 GW today, 100 GW targeted — more than an elevenfold expansion in about two decades. Nothing in the current structure of the industry delivers that, which is precisely why the law changed.
The three-stage programme, and why India built it that way
This is the oldest and most reliably examined element of the topic, and it is a response to a resource endowment rather than a preference.
India has modest uranium reserves and among the world's largest thorium reserves — concentrated in the monazite sands of the coastal belt, notably in Kerala, Tamil Nadu and Odisha. The problem is that thorium is fertile, not fissile: it cannot sustain a chain reaction by itself. It must first absorb a neutron and transmute into uranium-233, which is fissile. A programme that wants to run on thorium therefore has to manufacture its own fissile material first.
Homi Bhabha's three-stage design is the route from what India has to what India can use:
| Stage | Reactor | Fuel | Output |
|---|---|---|---|
| I | Pressurised Heavy Water Reactor (PHWR) | Natural uranium, heavy water as moderator and coolant | Electricity, plus plutonium-239 in the spent fuel |
| II | Fast Breeder Reactor (FBR) | Plutonium-239 with a thorium blanket | Electricity, plus more fissile material than consumed, breeding U-233 from thorium |
| III | Thorium-based reactors | U-233 + thorium | A self-sustaining thorium cycle |
Two features explain the design. First, PHWRs run on natural uranium, so India needed no enrichment capability to start — decisive for a country under technology-denial regimes after 1974. Second, a breeder produces more fissile material than it consumes, which is how the programme manufactures the U-233 that Stage III requires. The chain is: uranium gives plutonium, plutonium plus thorium gives U-233, U-233 plus thorium sustains itself.
The release states the current position plainly: 10 indigenous PHWRs approved in fleet mode, and pre-project activities for two 500 MW Fast Breeder Reactors — India remains, in effect, at the junction of Stages I and II, which is the honest thing to say. The programme's logic is sound; its timeline has always run behind its ambition.
Fuel vocabulary to carry: fissile materials sustain a chain reaction directly (U-235, Pu-239, U-233); fertile materials must first be converted (U-238, Th-232). Most of the world uses Low-Enriched Uranium in Light Water Reactors; India mainly uses natural uranium in PHWRs.
The legal change: what the SHANTI Act did
The SHANTI Act, 2025 — Sustainable Harnessing and Advancement of Nuclear energy for Transforming India — is the substantive news behind these backgrounders, and it is a larger change than the anodyne name suggests.
It repeals two statutes and replaces them with one:
- the Atomic Energy Act, 1962, which had reserved atomic energy to the state; and
- the Civil Liability for Nuclear Damage Act, 2010, India's nuclear liability law.
Three consequences matter.
Private ownership of plants. For the first time since Independence, private Indian companies and joint ventures may build, own, operate and decommission nuclear power plants, ending the operating monopoly of NPCIL. This is what makes a 100 GW target arithmetically conceivable: state financing alone cannot fund elevenfold expansion.
What the state keeps. Enrichment of nuclear material, production of heavy water, and management of spent fuel beyond on-site storage remain with the Central Government, meaning the Department of Atomic Energy. The sensitive end of the fuel cycle — the part with proliferation implications — is not liberalised. FDI in atomic energy remains prohibited, so "private" here means Indian private capital.
Liability. The 2010 Act was internationally notorious for Section 17(b), which gave the operator a right of recourse against the supplier — an unusual provision that made foreign vendors reluctant to sell reactors to India, since global practice channels liability exclusively to the operator. The new framework removes supplier liability and caps operator liability by plant capacity, aligning India with international conventions. Whether that is prudent harmonisation or a weakening of victim protection is a genuine debate, and a candidate should present it as one: the 2010 provision was a response to Bhopal, and the argument for supplier liability is that it creates an incentive for supplier quality. The counter-argument is that it priced India out of the reactor market for fifteen years.
The case being made for nuclear, with the numbers
Carbon efficiency. In FY 2025-26, one gigawatt of nuclear capacity avoided about 5.4 million tonnes of CO₂-equivalent, against 2.7 for hydropower, 1.6 for wind and 0.9 for solar. Cumulatively since 1969, the programme has avoided 851 million tonnes of CO₂-equivalent.
Read that table carefully, because the comparison is per unit of installed capacity, and the reason nuclear wins is the capacity factor. A gigawatt of solar generates only when the sun shines; a gigawatt of nuclear runs at high output nearly continuously. The figures measure availability as much as carbon intensity — which is exactly the point the second backgrounder makes when it emphasises baseload: the minimum uninterrupted power a grid needs to stay operational, for hospitals, communications, defence and industry. As the share of variable renewables rises, the value of dispatchable low-carbon capacity rises with it. That interaction sits within the wider study of government budgeting and energy policy and the CDS/OTA economy syllabus.
And the non-power applications, which the first backgrounder details and which are frequently asked:
- Healthcare — radiopharmaceuticals, imaging and cancer therapy through BARC, IGCAR, Tata Memorial Centre, TIFR and HRI; the 150-bed Homi Bhabha Cancer Hospital at Muzaffarpur inaugurated in 2025; 1.53 crore medical devices sterilised by radiation.
- Agriculture — radiation-induced mutagenesis for crop improvement; BARC has developed 70 crop varieties, including TBM-9 banana and RTS-43 sorghum released in 2025.
- Food preservation — irradiation to extend shelf life, cut post-harvest losses and meet phytosanitary requirements for export.
The institutions: the Department of Atomic Energy, with BARC (Mumbai) and IGCAR (Kalpakkam) as its principal research centres, NPCIL as operator, and the Atomic Energy Regulatory Board as the safety regulator — with India working alongside the IAEA on safety, security and safeguards. Tarapur, commissioned in 1969, was India's first nuclear power station.
🔑 Revision block
The documents. 28 August 2026 — two PIB backgrounders: Nuclear Energy in India: Applications, Safety, and Preparedness and Nuclear Energy Technology in India: Sustainable and Self-Reliant Future.
The position. 24 reactors at seven sites, 8.78 GW installed · nine under construction (7.5 GW) · 10 more in preparation · 10 PHWRs approved in fleet mode · pre-project work on two 500 MW Fast Breeder Reactors. Target: 100 GW by 2047 under the Nuclear Energy Mission for Viksit Bharat. ₹20,000 crore for indigenous Small Modular Reactors in Budget 2025-26. Tarapur (1969) was the first station.
Why three stages. India has modest uranium and vast thorium (monazite sands of Kerala, Tamil Nadu, Odisha). Thorium is fertile, not fissile — it must absorb a neutron to become U-233.
The three stages. I — PHWR on natural uranium (heavy water moderator/coolant), yielding Pu-239. II — Fast Breeder Reactor on Pu-239 with a thorium blanket, breeding U-233. III — thorium reactors on U-233 + thorium, self-sustaining.
Why PHWRs first. Natural uranium needs no enrichment — decisive under post-1974 technology denial.
Fuel vocabulary. Fissile: U-235, Pu-239, U-233. Fertile: U-238, Th-232. Most countries use LEU in Light Water Reactors; India uses natural uranium in PHWRs.
The SHANTI Act, 2025. Sustainable Harnessing and Advancement of Nuclear energy for Transforming India. Repeals the Atomic Energy Act, 1962 AND the Civil Liability for Nuclear Damage Act, 2010. Allows private Indian companies to build, own, operate and decommission plants — ending NPCIL's operating monopoly. Retained by the Centre (DAE): enrichment, heavy-water production, off-site spent-fuel management. FDI in atomic energy stays prohibited.
Liability. The 2010 Act's supplier recourse provision deterred foreign vendors. The new framework removes supplier liability and caps operator liability by plant capacity, aligning with international conventions. The debate: supplier liability incentivises quality (a post-Bhopal logic) versus it having priced India out of the reactor market.
Carbon numbers. Per GW of installed capacity in FY 2025-26, CO₂-equivalent avoided: nuclear 5.4 Mt · hydro 2.7 · wind 1.6 · solar 0.9. Cumulative since 1969: 851 Mt. Nuclear leads largely because of its capacity factor.
Baseload. The minimum uninterrupted power a grid needs — hospitals, communications, defence, industry. Its value rises as variable renewables grow.
Beyond electricity. Health — radiopharmaceuticals and cancer care via BARC, IGCAR, Tata Memorial Centre, TIFR, HRI; Homi Bhabha Cancer Hospital, Muzaffarpur (150 beds, 2025); 1.53 crore devices sterilised. Agriculture — radiation-induced mutagenesis; BARC has 70 crop varieties, including TBM-9 banana and RTS-43 sorghum (2025). Food — irradiation for shelf life and phytosanitary compliance.
Institutions. DAE · BARC (Mumbai) · IGCAR (Kalpakkam) · NPCIL (operator) · AERB (regulator) · IAEA cooperation.
🎯 Practice MCQs
Q1. The SHANTI Act, 2025 repeals which of the following? (a) Atomic Energy Act, 1962 and Civil Liability for Nuclear Damage Act, 2010 (b) Atomic Energy Act, 1962 only (c) Electricity Act, 2003 (d) Environment (Protection) Act, 1986 → (a).
Q2. In India's three-stage programme, the first stage uses: (a) natural uranium in Pressurised Heavy Water Reactors (b) enriched uranium in Light Water Reactors (c) plutonium in fast breeders (d) thorium directly → (a).
Q3. Thorium cannot directly sustain a chain reaction because it is: (a) fertile, not fissile (b) radioactive (c) too scarce (d) chemically unstable → (a) — it must convert to U-233.
Q4. The fissile isotope bred from thorium is: (a) Uranium-233 (b) Plutonium-239 (c) Uranium-235 (d) Uranium-238 → (a).
Q5. India's installed nuclear capacity, as stated in the release, is: (a) 8.78 GW (b) 7.5 GW (c) 100 GW (d) 24 GW → (a) — across 24 reactors at seven sites.
Q6. The Nuclear Energy Mission for Viksit Bharat targets what capacity by 2047? (a) 100 GW (b) 50 GW (c) 20 GW (d) 8.78 GW → (a).
Q7. Under the SHANTI Act, which activity remains with the Central Government? (a) Enrichment of nuclear material (b) Plant construction (c) Plant operation (d) Decommissioning → (a) — along with heavy-water production and off-site spent-fuel management.
Q8. India's first nuclear power station, commissioned in 1969, was at: (a) Tarapur (b) Kalpakkam (c) Kudankulam (d) Rawatbhata → (a).
Q9. Per gigawatt of installed capacity in FY 2025-26, CO₂-equivalent emissions avoided were highest for: (a) nuclear (b) hydropower (c) wind (d) solar → (a) — 5.4 Mt, against 2.7, 1.6 and 0.9 respectively.
Q10. Budget 2025-26 allocated ₹20,000 crore for: (a) indigenous Small Modular Reactors (b) fast breeder reactors (c) uranium mining (d) heavy water plants → (a).
Q11. The safety regulator for India's nuclear installations is the: (a) AERB (b) NPCIL (c) BARC (d) IAEA → (a) — NPCIL is the operator, BARC the research centre.
Q12. 'Baseload' electricity refers to: (a) the minimum uninterrupted power a grid needs to remain operational (b) peak evening demand (c) power from renewables only (d) electricity exported to neighbours → (a).
📋 How this gets asked (PYQ pattern)
Nuclear questions arrive in four dependable shapes. The three-stage item — matching a stage to its reactor type and fuel, where swapping the fuels of Stage I and Stage II is the standard error and the U-233 answer is the discriminator. The fissile-fertile item — sorting U-235, Pu-239 and U-233 from U-238 and Th-232, a pure-concept question. The institution item — DAE, BARC, IGCAR, NPCIL and AERB matched to their functions, with regulator versus operator the point being tested. The site item — matching a power station to its state, where Kudankulam (Tamil Nadu), Kakrapar (Gujarat), Rawatbhata (Rajasthan) and Narora (Uttar Pradesh) recur.
The fresh 2026 hook is the SHANTI Act, 2025 — what it repealed, what it opened to private participation, and what the state retained. A statement-type item claiming the Act permits FDI in atomic energy is almost written for this cycle, and it is false. As always, we describe the recurring pattern, not any exact past question.
Preparing for CDS or OTA? Nuclear energy pays across three sections at once — science, economy and current affairs — provided the three-stage logic is understood rather than memorised. Build the base with our CDS/OTA economy hub and notes on the government budget, follow the daily CDS/OTA current affairs, and prepare with our faculty in the upcoming Cavalier courses in Delhi.
✍️ Written by Aditya Tiwari — Economy & polity faculty at The Cavalier. Reviewed by the Cavalier Faculty Desk. The Cavalier, founded by ex-Army officers, has trained NDA/CDS/SSB aspirants since 2001 (Facebook · YouTube).
Source: PIB Backgrounders / Department of Atomic Energy, 28 August 2026. SHANTI Act provisions cross-verified with independent legal reporting.