Nuclear Technology

From Uranium to Thorium: India’s Nuclear Fuel Shift through ANEEL

Context: India’s nuclear energy strategy is witnessing a renewed push towards thorium-based fuel innovation. The Department of Atomic Energy (DAE) has stated that NTPC Ltd and Clean Core Thorium Energy (CCTE) are exploring the development and deployment of thorium-based ANEEL fuel for India’s Pressurised Heavy Water Reactors (PHWRs). This marks a strategic move to strengthen long-term energy security and reduce dependence on imported uranium.

Key Developments in India’s Nuclear Strategy

India continues to anchor its roadmap in the Three-Stage Nuclear Programme, based on the progression from uranium → plutonium → thorium. This structure ensures fuel sustainability and aligns with India’s unique resource endowment.

However, the strategy is evolving. Instead of only investing in infrastructure-heavy reactor expansion, India is now focusing on fuel innovation to improve efficiency and maximise output from existing nuclear assets. The development of advanced fuels such as ANEEL (Advanced Nuclear Energy for Enriched Life) reflects this shift.

Another significant change is the reorientation of thorium deployment. Earlier plans aimed at building dedicated thorium reactors, but current thinking prioritises adapting existing PHWR fleets for thorium-based fuel blends, reducing time and cost.

India’s commitment to a closed fuel cycle, including reprocessing of spent fuel, remains central to improving fissile recovery and reducing long-term waste burdens.

Why Thorium-Based ANEEL Fuel for PHWRs?

India’s uranium reserves are limited, whereas thorium deposits are among the largest globally. This creates a strong resource security incentive to diversify nuclear fuel sources.

Thorium-based ANEEL fuel offers multiple advantages:

Fleet Compatibility: PHWRs form the backbone of India’s nuclear capacity, and ANEEL can enhance performance without redesigning reactors.
Higher Fuel Efficiency: Thorium blends allow improved burn-up potential and better neutron economy.
Reduced Long-Lived Waste: Thorium cycles generate fewer long-lived transuranic elements compared to conventional uranium-plutonium cycles.
Safety Improvements: Thorium’s favourable reactor behaviour and thermal properties improve stability under stress conditions.

Thus, ANEEL fuel can act as a bridge between present infrastructure and India’s future thorium economy.

India’s Three-Stage Nuclear Programme

Stage 1 (PHWRs)
Uses natural uranium in PHWRs. India operates 19 PHWRs, which remain the backbone of nuclear generation.

Stage 2 (Fast Breeder Reactors)
Uses plutonium-based fuel to breed more fissile material. However, slow progress has delayed large-scale expansion.

Stage 3 (Thorium Phase)
Aims to use thorium to produce Uranium-233, enabling long-term, self-sustaining nuclear power.

Currently, nuclear power contributes around 3% of India’s electricity generation, but India targets 100 GW nuclear capacity by 2047.

Conclusion

Thorium-based ANEEL fuel represents a practical and strategic step in India’s nuclear transition. By upgrading existing PHWRs, India can strengthen energy security, reduce waste challenges, and move closer to a sustainable thorium-driven nuclear future.

Ocean Model affirms Fukushima Wastewater release is Safe

Context: A recent simulation study by Japanese researchers using an ocean circulation model has affirmed that Fukushima wastewater release is safe.

Relevance of the Topic: Prelims: Key idea about Nuclear contamination; Key facts about Tritium.

Japan releases wastewater from Fukushima Nuclear Plant

An earthquake followed by a tsunami in 2011 wrecked the Fukushima Daiichi Nuclear Power Plant in Japan, destroying its cooling system and causing reactor cores to overheat and contaminate water within the facility with highly radioactive material.
Since the disaster, power plant company TEPCO has been pumping in water to cool down the damaged reactors' fuel rods. Every day the plants produce contaminated water which is stored in around 1,000 tanks, which are already filled to 98% of their 1.37 million-ton capacity.
This water has been treated to remove most radioactive contaminants but still contains tritium (a radioactive isotope of hydrogen) and Carbon-14 which are difficult to separate from water.
In 2021, Japan’s government announced plans to release over one million tonnes of contaminated water from the Fukushima nuclear plant into the Pacific ocean over the next 30 years.

Rationale to release wastewater

There is a lack of available space for additional storage tanks, as well as due to safety risks and expense of managing the accumulating water.
Japan states that the water has been treated and diluted before releasing it into the ocean. The water contains about 190 becquerels of tritium per litre, below the World Health Organisation drinking water limit of 10,000 becquerels per litre (Bq/L). (Becquerel is a unit of radioactivity).

Associated Concerns:

The release has raised concerns among China and South Korea, as well as environmental and anti-nuclear groups regarding its potential impact on public health (increase the risk of cancer), seafood and marine environment.

Waste water released into the ocean off Fukushima will not be contained to waters surrounding Japan. It will be carried by ocean currents, particularly the cross-Pacific Kuroshio current, to other parts of the world.
Marine animals that migrate great distances, phytoplankton (free-floating organisms) and microplastics can all act as Trojan horses to spread radionucleotides far away.

Findings of the latest Research by Japanese Researchers:

Low radiation levels: As the nuclear facility is releasing tritiated water gradually, the Tritium levels (radiation level) is even lower than that due to natural and historical sources. The peaks from the routine discharge never exceed 0.002 Bq/L, which is 25x (25 times) lower than natural background radiation levels.
Impact of Warming: Warmer oceans might shift the Kuroshio Current a little North and strengthen eastward flow, speeding up tritium dispersion in the mid-Pacific. However, Tritium concentrations will still remain three orders of magnitude below detection threshold.

Since, Tritium has a half life of around 12 years, natural decay reduces long-term risk. Even under extreme warming or a worst-case eddy transport scenario, the levels of the Tritium would remain undetectable across the wider Pacific Ocean by 2099.

About Tritium:

Tritium is a radioactive isotope of Hydrogen with a half-life of about 12 years. Hydrogen has three isotopes:
- Protium- one proton and zero neutron
- Deuterium - one proton and one neutron
- Tritium - one proton and two neutrons
Occurrence: Naturally occurring tritium is extremely rare on Earth. The atmosphere has only trace amounts, formed by the interaction of Nitrogen with cosmic rays. It can be produced artificially as a low-abundance byproduct in nuclear reactors.
Uses:
- Energy source in radioluminescent lights for watches, gun sights, numerous instruments and tools.
- Radioactive tracer in a medical and scientific setting.
- Nuclear fusion fuel, along with more abundant deuterium, in tokamak reactors and hydrogen bombs.
Concerns: Tritium is easily absorbed by the bodies of living creatures and rapidly distributed via blood.

Project to curb Rhino Poaching through Radioactive Isotope Injection

Context: Researchers from South Africa have launched an anti-poaching campaign with a unique approach which involves injecting radioactive isotopes into Rhino horns. The method is claimed to be harmless for the Rhinos and allows customs agents to detect trafficked horns.

Relevance of the Topic: Prelims: Key facts about Radioactivity; Applications of Radioactivity.

Key Highlights of the Anti-Poaching Campaign

Method: Through a non-invasive procedure, Rhino horns are tagged with low doses of radioactive isotopes. This allows for their ready detection by radiation portal monitors (RPMs) already deployed at borders, ports, and airports worldwide to identify unauthorised nuclear materials.
Rationale: To facilitate detection of Rhino horns at international borders using existing radiation monitors to curb poaching.
Potential: This application can be extended to other vulnerable species like elephants and pangolins.

What is Radioactivity?

Radioactivity is the property of some unstable atoms (radionuclides) to spontaneously emit nuclear radiation (usually alpha particles or beta particles, often accompanied by gamma-rays) to transform into a more stable form. The radiation emitted can be traced using existing radiation monitors.
- Atoms found in nature are either stable or unstable.
- Instability of an atom's nucleus may result from an excess of either neutrons or protons. In such a case, the atom is radioactive and the nucleus has excess internal energy.
- A radioactive atom attempts to reach stability by ejecting nucleons (protons or neutrons), as well as other particles, or by releasing energy.
Common examples of Radionuclides: Tritium (isotope of Hydrogen and the lightest radionuclide), Carbon-14, Caesium-137, Thorium-232, Uranium-235, Uranium-238, Plutonium-238, Plutonium-239.

Applications of Radioactivity

Radioisotope Thermo-electric Generator (RTG): A radioactive material (Plutonium-238) is used which when decays produces heat. This heat is in turn used by a generator to produce electricity. E.g., the New Horizon spacecraft to Pluto uses RTG as an energy source for the spacecraft.
Medical Imaging: Radioactive isotopes are used in medical imaging techniques such as CT scans and PET scans.
Radiation Therapy: Radioactive isotopes (Cobalt-60) and (Cesium-137) are used to treat various types of cancer through radiation therapy.
Smoke Detectors: Smoke detectors use a small amount of radioactive material to detect smoke and trigger an alarm.
Industrial Radiography: Radioactive isotopes are used in industrial radiography to test the integrity of metal structures such as pipelines and oil rigs.
Carbon Dating: Carbon-14 is used in carbon dating to determine the age of ancient fossils and artefacts.
Nuclear Power: Uranium-235 is used to generate nuclear electricity through nuclear fission. Tritium is being explored as a potential nuclear fuel that can undergo nuclear fusion.
Food Irradiation: Radioactive isotopes (Cobalt-60 and Cesium-137) are used to sterilise and preserve food products.
Geological Dating: Radioactive isotopes (Uranium-238) are used to determine the age of rocks and minerals.
Sterilisation: Cobalt-60 is used to sterilise medical and surgical instruments.

India’s 1st Private Test Facility for Heavy Water Upgrade

Context: Mumbai-based TEMA India has been entrusted with testing the equipment required for upgrading of depleted heavy water, a crucial requirement for Pressurised Heavy Water Reactors in India. It is a significant step towards speeding up the operationalisation of nuclear power plants.

Relevance of the Topic: Prelims: India’s 1st private test facility for Heavy Water Upgrade; Heavy Water; Pressurised Heavy Water Reactors.

India’s 1st Private Test Facility for Heavy Water Upgrade

Until now, the assembling and testing of equipment for heavy water upgrade were centralised and done by Bhabha Atomic Research Centre (BARC).
TEMA India has inaugurated its test facility at Achchad in Palghar district, Maharashtra, where it will manufacture equipment such as distillation columns and integrate and test them before sending them to reactor sites for installation.
The facility was designed and built by TEMA India’s nuclear vertical under technology transfer from BARC and a ‘purchase order’ from Nuclear Power Corporation of India Ltd (NPCIL).

Significance:

Single-point solutionfor upgrading heavy water:
- Till now, the distillation columns and modules were manufactured by other vendors, and then assembled and tested by BARC. The entire process took 7-8 years.
- The decentralisation will reduce the time period by at least one to two years, and thus speeden up the operationalisation of nuclear power plants.

What is Heavy Water?

Heavy water (D2O) is a form of water (H2O) with deuterium (a heavier isotope of hydrogen), instead of regular hydrogen.
It is used as a coolant as well as moderator for slowing down fast-moving neutrons during a chain reaction essential for sustaining the nuclear fission process.
D2O needs to be 99.9% pure for working efficiently. With time it gets contaminated with light or regular water, thus requiring the depleted D2O to be upgraded back to 99.9% using a distillation process.

TEMA India has dispatched the first batch of tested distillation column sections for deployment at a unit of the Rawatbhata Nuclear Power Plant (RAPP-8) in Rajasthan, which is scheduled to go critical by December 2025.

Pressurised Heavy Water Reactor:

Fuel: Natural Uranium (unenriched)
Moderator and Coolant: Heavy water is used as both moderator and coolant.
Cooling System: Uses a combination of heavy water and light water to cool the reactor. Heat is transferred to a secondary loop, which then generates steam to drive turbines.
Control Rods: Boron or Cadmium control rods.
Fuel requirement: Annual requirement of fuel (UO2) of a 700 MW PHWR (at 85% Capacity Factor) is about 125 tons.
Advantages: Uses natural Uranium fuel, produces less high-level radioactive waste, and operates at lower pressures compared to some other reactor types.

India’s Nuclear Energy Generation Target

India has set its eyes at achieving 100 GW of installed nuclear energy capacity by 2047.
There are 24 nuclear reactors operational in India with an installed capacity of 8780 MW.
The government had approved construction of 10 more nuclear reactors in 2015- of which one has come onboard, while the rest (with a combined capacity of 13.6 GW) are under construction.
The immediate target is to achieve 22.4 GW of installed capacity by 2032.
The government has also launched a 20,000-crore Nuclear Energy Mission to develop Small Modular Reactors.

Also Read: Nuclear Energy Sector in Union Budget 2025-26

What happens if Iran Withdraws from the Nuclear Non-Proliferation Treaty?

Context: Amid the heightened military tensions between Iran and Israel, Iran's Parliament is preparing a Bill to potentially leave the Treaty on the Non-Proliferation of Nuclear Weapons (NPT).

Relevance of the Topic : Prelims: Key facts about Nuclear Non-Proliferation Treaty. Mains: Crisis in West Asia- Key Developments.

Nuclear Non-Proliferation Treaty (NPT)

NPT is a multilateral treaty, signed in 1968, aimed at limiting the spread of nuclear weapons including three elements:
- Non-proliferation
- Disarmament
- Peaceful use of Nuclear Energy.
It defines nuclear weapon states (NWS) as those that had manufactured and detonated a nuclear explosive device prior to 1 January 1967. Five NSW are China, France, Russia, the UK and the US. All the other states are non-nuclear weapon states (NNWS).
The Treaty does not affect the right of state parties to develop, produce, and use nuclear energy for peaceful purposes.
The International Atomic Energy Agency (IAEA) verifies NNWS compliance with commitments under the NPT not to acquire nuclear weapons.
India, Israel, and Pakistan possess nuclear weapons but have never accepted the NPT. India considers NPT as flawed and as it does not recognise the need for universal, non-discriminatory verification and treatment.

Iran is a signatory to NPT, and is obligated to allow IAEA inspections and limit enrichment. Recently, the IAEA’s Board of Governors has censured Iran for breaching its non-proliferation obligations.

According to the IAEA, Iran has 400 kg of uranium that is already enriched to 60%, just a few steps away from further enrichment to weapons-grade level of 90% or more. The total stockpile of uranium and other nuclear material would be much more.

Can Iran leave the NPT?

The United States has attacked three key nuclear installations in Iran- Fordow, Isfahan and Natanz. This marked the entry of the US into the ongoing conflict between Israel and Iran. Iran has the legal right to withdraw from the NPT owing to the US strikes.

Article 10 of NPT: Each Party shall in exercising its national sovereignty have the right to withdraw from the Treaty if it decides that extraordinary events, related to the subject matter of this Treaty, have jeopardised the supreme interests of its country.
A notice of withdrawal must be given to other parties and the United Nations Security Council (UNSC), three months in advance, and such notice shall include a statement of the extraordinary events it regards as having jeopardised its supreme interests.

Exiting the treaty raises two major concerns:

Increased opacity in Iran’s Nuclear program: It will keep Iran out of the IAEA’s purview and regular inspections. IAEA would lose access to visit nuclear-sites in Iran.
Set a precedent to exit NPT: It could set a precedent for other states to leave the global framework and weaken cooperation on nuclear non-proliferation.

However, remaining in the NPT does not necessarily signal an intention to build nuclear weapons, because signatories (like North Korea) have also developed weapons in the past.

Heaviest Proton emitter Astatine-188 detected

Context: Researchers have detected proton emission from 188At (astatine) isotope and measured its half-life. The isotope is currently recognised as the heaviest known proton emitter found till date.

Relevance of the Topic:Prelims: Key concepts- basics of an atom; half life; Applications of radioisotopes.

Key Concepts

Basics of an Atom

An atom contains a nucleus (with protons and neutrons) and electrons revolving around the nucleus.
Almost all of the mass of the atom is concentrated in the nucleus.
- The number of protons (Z) in an atom determines the atomic number of an element.
- The total number of protons and neutrons, called Nucleons, is called the Atomic Mass Number (A).
Atoms can be unstable (radioactive) due to imbalance in the number of protons and neutrons (proton-neutron ratio) inside the nucleus.
All elements with atomic numbers greater than 83 are considered radioactive, including Astatine (85), Uranium (92), Plutonium (94), and Thorium (90) etc.
These elements have unstable atomic nuclei, and over time, the unstable nuclei decay by releasing energy and radiation to reach a more stable configuration. They release energy in the form of three types of radiations: alpha, beta, and gamma.

Radioactive Half-life:

For a given radioisotope, the radioactive half-life is the time for half the radioactive nuclei in any sample to undergo radioactive decay.
After two half-lives, there will be one fourth the original sample, after three half-lives one eighth the original sample, and so forth.

188Astatine isotope

For the first time that an Astatine isotope decaying by proton emission was detected and its half-time was measured in a lab.
188Astatine (At-188) isotope decayed by emitting a proton. While isotopes often undergo radioactive decay by emitting alpha, beta, and gamma particles, rarely do they emit a proton. The measured half-life for the 188At is 190 microseconds.
At-188 isotope emits a proton and becomes 187-polonium isotope, which in turn decays via alpha decay into 183-lead and so on, until it reaches a stable nucleus.

Targeted Alpha Therapy (TAT):

TAT is an emerging and highly promising form of radiopharmaceutical therapy that involves the use of alpha-emitting isotopes to target and destroy cancer cells in the human body. In the therapy alpha particle-emitting radionuclides are injected into the tumor tissue.
One isotope of Astantine (Astatine-211) is one of the most promising alpha emitters for TAT of cancers.

France's Nuclear Sharing Proposal in Europe

Context: Recently, the French President has stated that France is open to dialogue on potentially stationing its nuclear weapons in other European countries to strengthen deterrence. This development occurred amid security concerns in Europe due to the ongoing Russia-Ukraine war.

Relevance of the Topic: Prelims: Key facts about Nuclear Sharing Model; Nuclear Non-Proliferation Treaty.

Why is France offering a broader Nuclear Role in Europe?

France’s willingness to consider stationing its nuclear weapons in other European countries is rooted in its long-standing vision of European strategic autonomy- the idea that Europe should be able to defend itself independently of outside powers, especially the United States.
The US President earlier stated that the US might not always protect NATO allies unless they spend 2% of their GDP on defence. This made European countries look for other ways to ensure their security.

What is the Nuclear Sharing Model?

Nuclear sharing involves a nuclear-weapon state stationing nuclear weapons on allied non-nuclear-weapon states’ territory with specific arrangements for potential use.
For example, within NATO, the US has maintained such arrangements for decades. Currently, B61 tactical nuclear gravity bombs (of the US) are deployed in five NATO states: Belgium, Germany, Italy, the Netherlands, and Turkey. Under these arrangements, the US retains legal ownership and custody of the warheads. The US President also retains the power to make the decision to use these weapons, following NATO consultation.
This Cold War-era posture aims to demonstrate alliance solidarity, and share nuclear risks.

Is it legal under International Law?

The 1968 Nuclear Non-Proliferation Treaty (NPT) is the primary legal instrument for regulating nuclear weapons.
Article I of the treaty prohibits nuclear-weapon states (like France) from transferring nuclear weapons or control over them.
Existing NATO nuclear sharing is justified by participants as being NPT-compliant because no transfer of legal ownership or control occurs in peacetime; the US maintains custody.
However, the non-proliferation advocates and various research institutions have consistently challenged this legality.

Security Implications of France’s decision:

Deploying additional nuclear weapons in Europe has varied security implications:

Proponents argue it could enhance deterrence against Russia by increasing NATO’s nuclear assets and demonstrating European resolve.
Russia would likely view such deployments as a significant escalation, potentially leading to military-technical measures in response as Russian officials have repeatedly warned against NATO’s eastward military expansion. Russia’s 2023 stationing of tactical nuclear weapons in Belarus is cited by some as a preceding escalatory step.

Nuclear Non-Proliferation Treaty (NPT):

NPT is a multilateral treaty aimed at limiting the spread of nuclear weapons including three elements: (1) Non-proliferation, (2) Disarmament (3) Peaceful use of Nuclear Energy.
It defines nuclear weapon states (NWS) as those that had manufactured and detonated a nuclear explosive device prior to 1 January 1967.
Five nuclear weapon states are China, France, Russia, the United Kingdom, and the United States. All the other states are therefore considered non-nuclear weapon states (NNWS).
The Treaty does not affect the right of state parties to develop, produce, and use nuclear energy for peaceful purposes.
The International Atomic Energy Agency (IAEA) verifies NNWS compliance with commitments under the NPT not to acquire nuclear weapons.
Negotiations of such an agreement should begin immediately after the NNWS accession to the NPT and enter into force within 18 months.

Why did India not sign the NPT?

India, Israel, and Pakistan possess nuclear weapons but have never accepted the NPT.
India did not sign the NPT, not because of its lack of commitment for non-proliferation, but because NPT creates a club of "nuclear haves" and a larger group of "nuclear have-nots" by restricting the legal possession of nuclear weapons to those states that tested them before 1967.
India considers NPT as a flawed treaty and as it does not recognise the need for universal, non-discriminatory verification and treatment.

US-Saudi Arabia Civil Nuclear Cooperation

Context: Saudi Arabia and the United States are currently in formal discussions to establish a framework for civil nuclear cooperation, amid enduring regional geopolitical complexities and nuclear proliferation risks.

Relevance of the Topic: Mains: Developments in West Asia & their possible impacts on India.

Why does Saudi Arabia want a Nuclear Programme?

Saudi Arabia’s push for nuclear energy is driven by multiple factors:

Reducing Oil Dependency: 68% of Saudi Arabia's electricity comes from natural gas and 32% from oil. With rising energy demand, the kingdom seeks to shift to nuclear energy to reduce domestic oil consumption and increase oil exports, thus maximising revenue.
Aligning with Vision 2030: Saudi Arabia aims to reduce oil dependence by diversifying its economy with a focus on technology, renewable energy, and sustainable growth.
Environmental Goals: Supports carbon emission reduction targets by shifting to cleaner energy sources.
Security Concerns: Saudi Arabia seeks nuclear capabilities to counter Iran’s nuclear ambitions, with a stated intent to develop nuclear weapons if Iran does so.
Leveraging Uranium Resources: Saudi Arabia’s untapped uranium reserves could reduce reliance on external suppliers and strengthen its nuclear program.

A nuclear program would enhance Saudi Arabia's global standing and boost its technological capabilities.

Challenges in Saudi Arabia’s Nuclear Ambitions:

US's top regional ally Israel has repeatedly voiced opposition to the Saudi civil nuclear programme.
Saudi Arabia’s nuclear ambitions may escalate tensions with neighbors, particularly Iran, potentially sparking a nuclear arms race in the Middle East (West Asia) region.
Saudi Arabia’s uranium enrichment plans raise fears of nuclear proliferation, with the U.S. demanding strict safeguards in any cooperation.

What is in it for the United States?

Diplomatic tool: Civil nuclear deal may serve as a diplomatic tool to strengthen U.S. influence in the Gulf.
Economic opportunities: A nuclear deal would allow U.S. companies to get contracts to build nuclear reactors in Saudi Arabia, giving American industry a major commercial advantage.
Monitoring: Partnering with Saudi Arabia gives the U.S. better visibility into the kingdom’s nuclear activities, helping prevent the misuse of nuclear technology for weapons.

However, the U.S. is concerned that giving Saudi Arabia control over uranium enrichment could open the door to nuclear weapons development.

As Saudi Arabia moves forward with its nuclear plans, its choices will affect not just its own energy future but also the peace and security of the Middle East. The program will play an important role in shaping regional politics and the world’s shift to cleaner energy.

Thorium Fuelled Nuclear Reactors

Context: Recently, China has successfully refuelled a working 2MW Thorium-fuelled molten salt reactor without causing a shutdown.

Relevance of the Topic: Prelims & Mains: Thorium fuelled Nuclear reactors; Advantages of Thorium reactors over Uranium reactors.

Thorium Reactor in China

China has developed a small, 2MW experimental Thorium Nuclear Reactor in the Gobi Desert, near the Mongolian border. It is operational from 2024.
China is working towards developing a 10 MW Thorium Nuclear Reactor for commercial use by 2030.
China’s efforts have put it at the forefront of both thorium-based fuel breeding and molten-salt reactors.

Thorium based Nuclear Reactors

Thorium (Th-232) is a fertile material that has to be converted to fissile material Uranium 233. The naturally occurring isotope Th-232 cannot be fissioned, but when irradiated in a reactor it absorbs neutrons and forms uranium-233, a fissile material that generates heat.
Coolant: Molten salt. China’s reactors use fluoride-based salts, which melt into a colourless, transparent liquid when heated to about 450 ºC. The salt acts as a coolant to transport heat from the reactor core.
Rather than solid fuel rods, molten-salt reactors use the liquid salt as a substrate for the fuel, such as thorium, to be directly dissolved into the core.
Compared to light water reactors in conventional nuclear power plants, molten salt reactors work at significantly higher temperatures. The result is that it can generate electricity much more efficiently.

Thorium reactors offer multiple Advantages:

As the world confronts the twin challenges of climate change and energy security, Thorium is making a comeback.

Less radioactive waste (burning thorium does not create plutonium, a highly toxic chemical element)
Cheaper alternative to Uranium and More fuel-efficiency
Far safer (because the fuel is already dissolved in liquid and they operate at lower pressures than do conventional nuclear reactors, which reduces the risk of explosive meltdowns)
Lower risk of nuclear weapons proliferation (its waste products are less weapons-grade than Uranium)
Does not need to be built near watercourses, since the molten salts serve as a coolant. (Conventional uranium power plants that need huge amounts of water to cool their reactors).

India and its plan to use Thorium Reactors

India has the world’s largest reserves of thorium — a million tonnes — particularly in its monazite-rich coastal sands.
As per the three-stage nuclear programme envisioned by nuclear scientist Dr Homi Bhabha, the country would use thorium reactors in the third stage. However, India has only commenced its second stage of nuclear programme in 2024.

Also Read: Three-stage Nuclear Program of India

India may allow 49% foreign ownership in Nuclear Power Plants

Context: India is considering allowing foreign firms to hold up to 49% ownership in its Nuclear Power Plants, aiming to boost its nuclear sector and reduce carbon emissions.

Relevance of the Topic: Prelims: Key facts about India’s Nuclear Energy Sector; Atomic Energy Act, 1962.

India’s Nuclear Energy Sector

As of 2024, the total Indian nuclear generation is just over 8 GW, which is just 2% of the country’s installed electricity capacity.
India aims to expand nuclear power capacity by 12 times to 100 gigawatts by 2047.
The government is considering changing its nuclear foreign investment framework. It would increase India’s nuclear capacity and replace carbon-intensive coal with cleaner energy.
Necessary legal changes are required in the Atomic Energy Act, 1962. The amendments to the Act would allow the government to issue licences to private companies to build, own and operate a plant and mine and manufacture atomic fuel.

Atomic Energy Act, 1962

The Act provides for the development, control and use of atomic energy for the welfare of the people of India and for other peaceful purposes.
The central government through NPCIL (Nuclear Power Corporation of India) holds the authority for activities related to nuclear energy, including its production, development, use, and disposal.
The Act restricts private companies from owning and operating nuclear power plants in India.
The 2015 amendment to the Atomic Energy Act, allows NPCIL to form joint ventures with other public sector units (PSUs) to secure funding for new projects. However, this does not extend to private or foreign companies.
Currently, private companies can participate in specific areas like supplying components and reactors, but not owning or operating plants. Discussions are ongoing about allowing Public-Private Partnerships (PPPs). This would require amendment to the Act.

Also Read: Nuclear Energy Sector in Union Budget 2025-26

However, the foreign nuclear investments would still require prior government approval rather than be allowed automatically.

India's first prototype Fast Breeder Reactor to be commissioned by 2026

Context: India's first prototype fast-breeder reactor (500 MW) in Tamil Nadu's Kalpakkam is expected to be commissioned in 2026. It will mark the second stage of India's three-stage nuclear programme that aims to recycle spent fuel to reduce the inventory of radioactive waste.

Relevance of the topic:

Prelims: Prototype Fast Breeder Reactor; India’s three-stage Nuclear programme.

Mains: Advantages and Challenges associated with Fast Breeder Reactors.

Major Highlights:

On completion of the commissioning of PFBR, the project will generate 500 MW of electricity.
On March 4, 2024, the core loading of India’s first indigenous PFBR was commenced at Kalpakkam, Tamil Nadu.
- Core loading is the process of placing nuclear fuel assemblies inside the core of a nuclear reactor.
- Core loading operation is a precursor to the nuclear plant going “critical” (the beginning of a self-sustaining nuclear fission reaction that will eventually lead to the generation of power).
Core loading marks a historic milestone marking entry into the vital second stage of India’s three-stage nuclear programme.

Significance of Fast Breeder Reactors (FBR):

Significant reduction in nuclear waste generated as FBR utilises/reprocesses the radioactive waste (Plutonium-239) as fuel from the first stage.
Advanced reactor with inherent passive safety features ensuring a prompt and safe shut down of the plant in the event of an emergency.
Both the capital cost and the per unit electricity cost is comparable to other nuclear and conventional power plants.
Stepping stone for the third stage of India’s Nuclear Programme. Can aid in conversion of fertile Thorium 232 to fissile Uranium 233, that will be used in the 3rd stage. Thus, FBRs can aid in the utilisation of India’s abundant Thorium reserves.

Challenges associated with Fast Breeder Reactors:

Radioactive Nuclear Waste:
- Nuclear waste produced in the Thorium fuel cycle contains Caesium-137, Actinium-227, Radium-224, Radium-228 and Thorium-230. All these are radioactive and demand additional investment in nuclear waste handling.
Safety risks of Sodium Coolants:
- Liquid sodium used as coolant in the FBRs reacts violently with water and burns if exposed to air. Thus, any leaks in the systems can result in a major sodium-water fire.
- The necessity of keeping air away from sodium makes refuelling and repair of these reactors much more difficult.
Economic Competition from Renewable Energy:
- Continuous decline in the prices of renewable energy sources (Solar & Wind energy). This has resulted in critics arguing for stopping further development of nuclear power.
Emergence of Small Modular Reactors:
- Small Modular Reactors (SMRs) are gaining popularity due to their advantages over traditional nuclear reactors- as SMRs can work with low-enriched uranium, have a maximum capacity of 300 MW, require less land and reduced cost.
Increasing domestic and external availability of Nuclear resources:
- The basic rationale behind going for the three-stage nuclear program was that India had limited uranium resources.
- However, with expanding discovery of domestic natural uranium in India (Tumulapalle etc.) and waiver from Nuclear Suppliers Group means that it is no longer difficult to source Uranium for conventional PHWRs in India for meeting its domestic needs.
- These developments reduce the urgency of deploying thorium-based reactors and shift focus back to conventional nuclear technologies.

Nevertheless, the three-stage nuclear power program is imperative to meet India's twin goals of energy security and sustainable development.

Rising power demand in India and the Hydrogen Factor

Context: India is the third highest energy consumer in the world. As India’s economy is expanding, India faces twin challenges- meeting growing energy demand and production of sustainable energy. In this context, India can rely on two alternatives - Nuclear Energy and Hydrogen as an energy source, to achieve a net-zero economy

Relevance of the Topic: Mains: Alternatives to meet the growing Energy demand of India.

India’s Net-Zero Imperative

Presently, the power sector is dominated by fossil fuels (particularly coal) which is used to generate electricity, provide heat and molecules for industrial processes (carbon is used to reduce iron ore to produce steel).
The goal of achieving a net-zero economy by 2070 can be realised only by massive electrification of end uses of energy (from transport to industry).
Solar and wind electricity cannot provide all the electricity that India needs owing to their intermittency, and thus India has to increase the share of non-polluting alternatives like Nuclear Energy and Green Hydrogen, in its energy mix.

Crucial Role of Nuclear Energy

India has set an aspirational target to reach 100 GW of installed capacity based on nuclear power by 2047. As of January 2025, India’s nuclear capacity is 8.18 GW (8180 MW).
Nuclear Power Corporation of India Limited (NPCIL) has announced an ambitious programme to set up several 700 MW Pressurized Heavy Water Reactors (PHWRs). (E.g., 26 units of 700 MW capacity are announced/set to be completed in upcoming years)
Many PSUs and departments such as the Indian Railways are looking to deploy nuclear power plants. NPCIL has invited proposals from the industry for setting up 220 MW PHWRs (Bharat Small Reactors) for its captive use.

Also Read: Nuclear Energy Sector in Union Budget 2025-26

Green Hydrogen or Low-carbon Hydrogen

In the coming years, the share of electricity provided by low-carbon sources (hydro, nuclear, solar and wind) will increase.
Excess/surplus energy can be used to produce green hydrogen or low-carbon hydrogen. It will solve the dual problem of storing excess energy and production of sustainable energy (green hydrogen).
Electrolysers are low-cost equipment and can be operated at different power levels. This hydrogen can be used to meet the energy demand of the end-use industry.

As India races towards the net-zero economy by 2070, India needs a robust energy policy that focuses on expanding Nuclear Energy and leverage low-carbon Hydrogen to handle/utilise surplus energy and meet energy needs.

Also Read: Hydrogen as an alternative fuel: Explained