Discuss the rationale behind India's three-stage nuclear power programme. How does thorium utilisation address India's long-term energy security?

Q. Discuss the rationale behind India's three-stage nuclear power programme. How does thorium utilisation address India's long-term energy security? (15 marks, 250-350 words)

Conceived by Dr. Homi Bhabha, India's three-stage nuclear power programme rests on a closed fuel cycle designed to match the country's resource endowment — limited uranium but among the world's largest thorium reserves — making nuclear energy a route to long-term energy security rather than a new import dependency [1][2].

Rationale behind the three-stage design - Resource logic: scarce natural uranium is used first in indigenous Pressurised Heavy Water Reactors (PHWRs) (Stage 1), whose spent fuel is reprocessed rather than discarded [1]. - Fuel multiplication: plutonium from reprocessed PHWR fuel powers Fast Breeder Reactors (FBRs) in Stage 2, breeding more fissile material than consumed — the PFBR at Kalpakkam marks this transition [1]. - Deferred thorium stage: large-scale thorium use through Uranium-233 follows only once adequate breeder capacity exists, since thorium-232 is fertile, not fissile, and needs a fissile seed [1][2]. - Technological self-reliance: denied full access to global nuclear commerce for decades, India built PHWR, reprocessing and breeder capability indigenously.

Thorium and long-term energy security - Insulation from geopolitics: domestic thorium reduces exposure to enriched-uranium suppliers and price shocks, unlike fossil-fuel imports [2]. - Scale and continuity: thorium underpins the target of 100 GW nuclear capacity by 2047, with capacity expanding through reactors now under construction across several states [3]. - Clean, firm baseload: nuclear supplies round-the-clock low-carbon power complementing variable solar and wind in the net-zero pathway [3]. - New policy push: the Nuclear Energy Mission (Union Budget 2025-26) provides ₹20,000 crore for Small Modular Reactors, targeting five indigenous SMRs by 2033 [4], while amendments to the Atomic Energy Act, 1962 and Civil Liability for Nuclear Damage Act, 2010 are under examination to bring in private capital [5].

Progress has been slower than envisaged, as breeder commissioning gates the thorium stage. Sustained FBR deployment, timely legislative reform and safety oversight under AERB can convert India's thorium advantage into durable, low-carbon energy security consistent with its Net-Zero 2070 commitment.

(~330 words)

Sources: 1. PARLIAMENT QUESTION: Closed Fuel Cycle Technology, DAE (PIB) — three-stage sequence, closed fuel cycle, PHWR–FBR–thorium logic, PFBR Kalpakkam 2. PARLIAMENT QUESTION: Leveraging India's Thorium Reserves (PIB) — limited uranium, large thorium reserves, U-233 route, import insulation 3. A New Chapter in India's Nuclear Journey — DAE Factsheet (PIB) — 100 GW by 2047 roadmap, reactors under construction, clean-energy role 4. Nuclear Power in Union Budget 2025-26, Department of Atomic Energy (PIB) — Nuclear Energy Mission, ₹20,000 crore SMR outlay, five SMRs by 2033 5. PARLIAMENT QUESTION: Nuclear Energy Mission (PIB) — proposed amendments to the Atomic Energy Act, 1962 and Civil Liability for Nuclear Damage Act, 2010 for private participation