Nuclear Energy: India's Three-Stage Programme

India's three-stage nuclear programme (Homi Bhabha, 1954) aims to utilize thorium reserves (world's largest) for energy independence. Stage 1: PHWR (Pressurized Heavy Water Reactors) using natural uranium, producing plutonium. Stage 2: FBR (Fast Breeder Reactors) using plutonium, breeding U-233 from thorium. Stage 3: Thorium-based reactors (AHWR) using U-233. Current: Stage 1 mature (22 reactors, ~7 GW), Stage 2 (PFBR Kalpakkam, 500 MWe, criticality 2024), Stage 3 R&D.[TOPIC CLASSIFICATION]

• Topic type: Science & Technology - Nuclear Energy
• PYQ frequency: High
• Exam stage: Prelims + Mains
• Primary GS paper: GS 3

[EXAMINER REASONING]

1. Trap: Confusing the three stages. Stage 1 = PHWR (natural U, produces Pu). Stage 2 = FBR (Pu, breeds U-233 from Th). Stage 3 = Thorium reactors (U-233). Many aspirants reverse Stage 2 and 3.
2. Most confused: PFBR (Prototype Fast Breeder Reactor, Kalpakkam, 500 MWe) is Stage 2, not Stage 3. It uses plutonium-uranium carbide fuel and breeds U-233 from thorium blanket. Many aspirants think PFBR is thorium reactor.
3. Key anchor: India's thorium reserves: ~846,000 tonnes (world's largest, 25% global). Uranium reserves: limited (~70,000 tonnes). Three-stage logic: limited uranium -> plutonium -> thorium. AHWR (Advanced Heavy Water Reactor, 300 MWe) is Stage 3 design.
4. Current affairs hook: PFBR Kalpakkam (500 MWe) achieved criticality (2024), approaching commercial operation. KAPP 3&4 (700 MWe PHWR) operational. Jaitapur (6x1650 MWe EPR, France) and Kovvada (6x1208 MWe AP1000, USA) pending. Civil nuclear liability (CLND Act 2010) issues. NSG membership bid.
5. Mains hinge: Evaluate: Can India's three-stage programme deliver energy security? The PFBR delays, thorium technology challenges, civil nuclear liability (CLND Act), and international cooperation (NSG, Jaitapur, Kovvada) are the Mains tensions.

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Core Concept

India's three-stage nuclear programme (Homi Bhabha, 1954) leverages vast thorium reserves (~846,000 tonnes, 25% world). Stage 1: PHWR (Pressurized Heavy Water Reactor) using natural uranium (U-238), produces plutonium (Pu-239). 22 reactors (~7 GW). Stage 2: FBR (Fast Breeder Reactor) uses plutonium, breeds U-233 from thorium blanket. PFBR (Prototype FBR, Kalpakkam, 500 MWe) achieved criticality 2024. Stage 3: Thorium-based reactors (AHWR, Advanced Heavy Water Reactor, 300 MWe) use U-233, self-sustaining thorium cycle.

Current status: Stage 1 mature (22 PHWRs, ~7 GW, KAPP 3&4 700 MWe each). Stage 2: PFBR Kalpakkam (500 MWe) criticality 2024, fuel loading. Stage 3: AHWR (300 MWe) design ready, awaiting site. Thorium reserves: ~846,000 tonnes (Kerala, Tamil Nadu, Odisha monazite sands). Uranium: limited (~70,000 tonnes, Jharkhand, Andhra, Meghalaya).

International: Indo-US 123 Agreement (2008), NSG waiver (2008), Jaitapur (6x1650 MWe EPR, EDF), Kovvada (6x1208 MWe AP1000, Westinghouse), Chhaya Mithi Virdi (6x1100 MWe, Russia). Civil Liability for Nuclear Damage Act (2010): supplier liability clause contentious. NSG membership bid (China blocks).