1. India’s installed nuclear power capacity constitutes a dominant share in its energy mix.
2. Prototype Fast Breeder Reactor (PFBR) achieving criticality marks India’s transition to Stage II of its nuclear programme.
3. Pressurised Heavy Water Reactors (PHWRs) in India use enriched uranium as fuel.
Which of the statements given above is/are correct?
Core Concept Explanation: India’s nuclear power programme follows a three-stage fuel cycle strategy to optimise limited uranium and vast thorium reserves. Stage I (PHWRs) produces plutonium; Stage II (Fast Breeder Reactors) uses plutonium to breed more fissile material; Stage III aims at thorium utilisation (U-233 cycle). The achievement of criticality in PFBR signifies transition into Stage II. Despite its strategic importance, nuclear energy contributes only about 3% of India’s electricity mix.
Statement 1 – Incorrect: Nuclear power does not constitute a dominant share in India’s energy mix. Installed capacity is around 8.8 GW and contributes roughly 3% of electricity generation, while coal (~70%) and renewables dominate. UPSC trap = strategic importance ≠ quantitative dominance.
Statement 2 – Correct: The Prototype Fast Breeder Reactor (PFBR) at Kalpakkam achieving criticality marks India’s entry into Stage II. Fast Breeder Reactors use plutonium-239 and breed more fissile material (including U-233 from thorium), ensuring long-term fuel sustainability.
Statement 3 – Incorrect: PHWRs use natural uranium (about 0.7% U-235) along with heavy water as moderator and coolant. They are designed to avoid dependence on uranium enrichment, which is a key strategic advantage.
1. It replaces both the Atomic Energy Act, 1962 and the Civil Liability for Nuclear Damage Act, 2010.
2. It allows private sector participation only in nuclear fuel fabrication but not in plant operation.
3. It introduces a tiered liability structure based on reactor capacity.
Which of the statements given above is/are correct?
Core Concept Explanation: The SHANTI Act, 2025 (Sustainable Harnessing and Advancement of Nuclear Energy for Transforming India) represents a structural overhaul of India’s nuclear legal framework, aimed at transitioning from a state monopoly model to a regulated, investment-friendly ecosystem. Its core reform lies in liability restructuring and institutional strengthening, which were major bottlenecks for private and foreign participation.
Statement 1 – Correct: The SHANTI Act repeals and replaces both the Atomic Energy Act, 1962 and the Civil Liability for Nuclear Damage Act, 2010, consolidating them into a single unified framework covering licensing, safety, and liability.
Statement 2 – Incorrect: The Act ends the earlier state monopoly by allowing private Indian companies and joint ventures to build, own, and operate nuclear power plants. However, the government retains control over strategic segments such as nuclear fuel production and radioactive waste management.
Statement 3 – Correct: The Act introduces a tiered (graded) liability structure, replacing the earlier flat cap of ₹1,500 crore. Liability now ranges from ₹100 crore to ₹3,000 crore, depending on reactor type and capacity, making the regime more rational and investment-friendly.
Reactor Type : Feature
1. PHWR : Uses natural uranium and heavy water
2. BWR : Backbone of India’s nuclear programme
3. VVER : Russian-designed pressurised water reactor
Which of the pairs given above are correctly matched?
Core Concept Explanation: India’s nuclear reactor mix reflects a strategy of indigenisation (PHWR dominance) combined with selective foreign collaboration (VVER). PHWRs form the backbone of Stage I due to fuel advantages and plutonium generation, while BWRs remain limited legacy imports.
Option (a) – Incorrect: Pair 2 is incorrect; PHWR, not BWR, is the backbone of India’s nuclear programme.
Option (b) – Correct: Pair 1 is correct (PHWR uses natural uranium and heavy water); Pair 3 is correct (VVER is a Russian-designed pressurised water reactor).
Option (c) – Incorrect: Includes incorrect Pair 2.
Option (d) – Incorrect: Inclusion of incorrect Pair 2 invalidates the option.
Core Concept Explanation: HALEU (High-Assay Low-Enriched Uranium) refers to uranium enriched between 5% and 20% U-235 (typically up to 19.75%). It bridges the gap between conventional reactor fuel (<5%) and highly enriched uranium (>20%), enabling compact reactor designs, longer fuel cycles, and higher efficiency—making it critical for advanced reactors and Small Modular Reactors (SMRs).
Option (a) – Incorrect: Uranium enriched above 20% U-235 is classified as Highly Enriched Uranium (HEU). While weapons-grade uranium is typically ~90%, anything above 20% is considered direct-use material for nuclear explosives or specialised applications.
Option (b) – Correct: HALEU lies in the 5%–19.75% enrichment band, offering higher fissile content than conventional fuel while remaining below the HEU threshold. It is widely used in advanced reactor designs and SMRs.
Option (c) – Incorrect: Uranium enriched below 5% U-235 is Low-Enriched Uranium (LEU), which fuels most existing commercial light water reactors (LWRs).
Option (d) – Incorrect: Thorium (Th-232) is a different element and is fertile, not fissile. HALEU refers specifically to uranium enrichment levels, though it can be combined with thorium in advanced fuel cycles.
1. The “fleet mode” approach adopted by NPCIL aims to standardise reactor construction to achieve economies of scale.
2. The joint venture ASHVINI is associated with a multi-unit PHWR project in Rajasthan.
3. With SHANTI Act, NPCIL ceases to have any operational or technical role.
Which of the statements given above are correct?
Core Concept Explanation: India’s nuclear expansion strategy combines execution efficiency (fleet mode) with institutional innovation (JV model) while retaining state-led technical control through NPCIL. The approach seeks to scale capacity rapidly, reduce costs, and enable partnerships without diluting strategic oversight.
Statement 1 – Correct: The “fleet mode” approach involves simultaneous construction of multiple standardised 700 MWe PHWR units (10 reactors). This enables:
Statement 2 – Correct: ASHVINI (Anushakti Vidhyut Nigam Limited) is a joint venture between NPCIL and NTPC. It is implementing a 4 × 700 MWe PHWR project at Mahi Banswara (Rajasthan), combining nuclear expertise with financial and project execution capacity.
Statement 3 – Incorrect: The SHANTI Act does not eliminate NPCIL’s role. Instead, it:
1. SMR-55 is designed for decentralised electricity generation.
2. BSMR-200 is meant only for greenfield sites.
3. HTGRs are suitable for hydrogen production.
Which of the statements given above are correct?
Core Concept Explanation: Small Modular Reactors (SMRs) represent a shift towards flexible, scalable, and decentralised nuclear deployment. Unlike large reactors, SMRs are designed for off-grid power, industrial applications, repurposing existing infrastructure, and clean energy transitions (including hydrogen production).
Statement 1 – Correct: SMR-55 (55 MWe), designed by Bhabha Atomic Research Centre (BARC), is a modular PWR intended for:
Statement 2 – Incorrect: BSMR-200 (220 MWe) is not limited to greenfield sites. A key objective is repurposing retired coal power plants (brownfield sites), leveraging existing:
Statement 3 – Correct: High-Temperature Gas-Cooled Reactors (HTGRs) operate at very high temperatures, enabling thermo-chemical hydrogen production (e.g., Iodine–Sulphur cycle), making them suitable for clean hydrogen generation.
1. HALEU enables smaller cores and longer fuel cycles.
2. PHWRs require HALEU as primary fuel.
3. SHANTI Act allows private participation in enrichment activities.
How many of the statements given above are correct?
Core Concept Explanation: India’s nuclear programme highlights the link between fuel type and reactor design. While HALEU enables advanced reactors and SMRs, India’s existing backbone (PHWRs) relies on natural uranium. Despite liberalisation, strategic segments of the fuel cycle (like enrichment) remain under state control.
Statement 1 – Correct: HALEU (5%–20% U-235) has higher fissile content than conventional fuel, which:
Statement 2 – Incorrect: PHWRs use natural uranium (0.7% U-235) as fuel and heavy water as moderator/coolant. They are specifically designed to avoid enrichment dependence.
Statement 3 – Incorrect: Under the SHANTI Act, private participation is allowed in plant construction and operation, but uranium enrichment and fuel-cycle activities remain under state control for strategic and security reasons, handled by the Department of Atomic Energy (DAE).
1. AERB has been granted statutory status and is accountable to Parliament.
2. AERB has inspection, search and seizure powers.
3. AERB functions under NPCIL.
Which of the statements given above are correct?
Core Concept Explanation: Recent reforms (via the SHANTI Act, 2025) aim to establish a clear separation between regulator and operator in India’s nuclear sector. The focus is on enhancing regulatory independence, transparency, and enforcement capacity, aligning with global best practices in nuclear safety governance.
Statement 1 – Correct: The Atomic Energy Regulatory Board (AERB), earlier created by executive order (1983), has now been granted statutory status.
Statement 2 – Correct: The AERB now has enhanced enforcement powers, including:
Statement 3 – Incorrect: AERB does not function under NPCIL.