Nuclear Technology: Energy, Programme and Policy

Basics of nuclear energy

Nuclear fission: a heavy nucleus such as uranium-235 or plutonium-239 absorbs a neutron and splits into lighter nuclei. This releases energy (by E = mc²) and 2–3 neutrons that sustain a chain reaction.

Nuclear fusion: light nuclei such as hydrogen isotopes (deuterium and tritium) combine, as in the Sun. Fusion releases more energy per unit mass and produces little long-lived waste, but it is not yet commercially viable.

Parts of a reactor:

• Fuel: natural or enriched uranium, plutonium, thorium-derived U-233.
• Moderator: slows neutrons so they cause more fission. Heavy water (D₂O), light water or graphite.
• Control rods: absorb neutrons to control the reaction. Made of boron or cadmium.
• Coolant: carries heat away. Water, heavy water, or liquid sodium in fast reactors.
• Containment: a structure that prevents the release of radiation.

Reactor types:

• PHWR (Pressurised Heavy Water Reactor): uses natural uranium and heavy water. It is the mainstay of India's fleet, and is designed indigenously, with 220 MW and 700 MW units.
• LWR/PWR (light water): needs enriched uranium. India's Kudankulam reactors (Russian VVER) are of this type.
• Fast Breeder Reactor: unmoderated fast neutrons, which breed more fissile material than they consume.

Enrichment: natural uranium is about 0.7% U-235. Power reactors need about 3–5%, and weapons need over 90%.

India's three-stage nuclear programme

Background: proposed by Dr. Homi J. Bhabha in the 1950s. India has limited uranium but about 25% of the world's thorium reserves, mainly in monazite sands of the Kerala, Tamil Nadu and Odisha coasts.

Stage 1: PHWRs. Natural uranium fuels PHWRs, producing power and plutonium-239 in spent fuel.

Stage 2: Fast Breeder Reactors. Plutonium-based fuel with a uranium-238 blanket breeds more plutonium. Later, a thorium blanket produces U-233.

• The Fast Breeder Test Reactor (Kalpakkam, 1985) was the first.
• The 500 MWe Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, built by BHAVINI, began core loading in March 2024. It has been delayed for over a decade.

Stage 3: Thorium-based reactors using U-233 and thorium, aiming at long-term energy independence. The Advanced Heavy Water Reactor (AHWR) design is being developed by BARC.

Status and expansion

Capacity: India has about 8.8 GW of installed nuclear capacity from about 25 reactors, giving about 3% of electricity. Reactors run at:

• Tarapur (Maharashtra), the first, in 1969;
• Rawatbhata (Rajasthan);
• Kalpakkam (Tamil Nadu);
• Narora (UP);
• Kakrapar (Gujarat), where India's first 700 MW PHWR reached criticality in 2021;
• Kaiga (Karnataka);
• Kudankulam (Tamil Nadu).

Operator: the Nuclear Power Corporation of India (NPCIL).

Plans:

• 10 indigenous 700 MW PHWRs in fleet mode (approved 2017);
• the Gorakhpur project in Haryana;
• Kudankulam units 3–6;
• a target of about 22 GW by 2031–32.

Nuclear Energy Mission (2025–26 Budget):

• a target of 100 GW by 2047;
• ₹20,000 crore for research on Small Modular Reactors (SMRs), with at least five indigenous SMRs operational by 2033;
• Bharat Small Reactors (220 MW PHWR derivatives) for industrial captive use, built in partnership with the private sector.

Legal changes needed:

• Atomic Energy Act 1962: currently only the government and its companies can operate nuclear plants. NPCIL has joint ventures with NTPC (ASHVINI, 2024).
• Civil Liability for Nuclear Damage Act 2010 (CLNDA): Section 17(b) gives the operator a right of recourse against suppliers for defective equipment. Foreign suppliers say this deters them.

In 2025 the government announced amendments to both laws to allow private participation. Check the current legislative status.

International dimension

The 1974 "Smiling Buddha" test at Pokhran led to the creation of the Nuclear Suppliers Group (NSG), which then isolated India from nuclear trade.

Pokhran-II (May 1998, "Operation Shakti"): India declared itself a nuclear weapons state. Its nuclear doctrine (2003):

• No First Use;
• credible minimum deterrence;
• massive retaliation;
• no use against non-nuclear states;
• political control through the Nuclear Command Authority.

India–US civil nuclear deal (2005–2008):

• India separated civil and military facilities, placing civil ones under IAEA safeguards (the India-specific safeguards agreement and the Additional Protocol, 2014);
• the NSG waiver (September 2008) allowed nuclear trade.

Agreements followed with France (Jaitapur, 6 EPRs planned, stalled), Russia (Kudankulam), the US (Kovvada, with Westinghouse, stalled), Canada, Australia and Kazakhstan for uranium supply, and Japan (2016).

Not signed: India has not signed the NPT (discriminatory) or the CTBT, but maintains a voluntary moratorium on testing.

Memberships: India is in the MTCR (2016), the Wassenaar Arrangement (2017) and the Australia Group (2018). Its NSG membership is blocked, mainly by China.

Safety, waste and public concerns

Regulator: the Atomic Energy Regulatory Board (AERB, 1983) is set up under the Atomic Energy Act but reports to the Atomic Energy Commission. Critics question its independence. The Nuclear Safety Regulatory Authority Bill (2011) lapsed.

Accidents worldwide:

• Three Mile Island (US, 1979);
• Chernobyl (USSR, 1986);
• Fukushima Daiichi (Japan, 2011, caused by an earthquake and tsunami).

Fukushima led to protests at Kudankulam and Jaitapur, and to safety reviews.

Waste: India follows a closed fuel cycle, reprocessing spent fuel to recover plutonium, which reduces long-lived waste. High-level waste is vitrified (immobilised in glass) at BARC facilities. A deep geological repository is still to be built.

Other applications of nuclear technology:

• medicine: radioisotopes for cancer diagnosis and treatment (cobalt-60, technetium-99m);
• agriculture: radiation-induced mutant crop varieties (BARC), food irradiation to extend shelf life;
• industry: radiography;
• water: desalination.

Analysis

For nuclear power:

• low-carbon baseload power;
• high capacity factor;
• small land footprint;
• energy security through thorium.

Against:

• high capital cost and long gestation;
• safety and waste concerns;
• liability issues;
• local opposition;
• dependence on imported fuel for some plants.

SMRs promise modular, factory-built units with passive safety. They could replace retiring coal plants on the same sites, but their economics are still unproven worldwide.

Common prelims traps

• PHWRs use natural uranium with a heavy water moderator.
• India has large thorium reserves, not uranium reserves.
• Kudankulam uses Russian VVER (light water) reactors.
• No First Use is part of India's doctrine, but India keeps the option of a nuclear response to chemical or biological attacks.

Quick self-test

1. *What does a breeder reactor do?* Produces more fissile material than it consumes.
2. *Where is the PFBR?* Kalpakkam, Tamil Nadu.
3. *What is CLNDA Section 17(b)?* The operator's right of recourse against suppliers.

Practice: Mains question

*"Thorium holds the key to India's long-term energy security." Explain India's three-stage nuclear programme and the challenges in realising it. (250 words)*

Key terms

• Criticality: the state in which a reactor sustains a steady chain reaction.
• Heavy water: water containing deuterium; it is an efficient moderator. India produces it at Heavy Water Board plants.
• Spent fuel: fuel removed from a reactor after use, which contains fission products and plutonium.
• Safeguards: IAEA inspections that verify nuclear material is not diverted to weapons.

• Half-life: the time taken for half of a radioactive substance to decay.