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Each card jumps to that country's flagship plant and — where a full country profile exists — its dedicated page. Prefer to read start to finish? Scroll on.
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India
Full section on this page
Kudankulam and Tarapur · NPCIL · Kudankulam is a Russia-India partnership, expanding to 6 units.
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United States
Dedicated project page →
Vogtle — first new US nuclear units in 30+ years (AP1000, completed 2023–24), plus Palo Verde, the largest US plant.
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Japan
Full country profile →
Kashiwazaki-Kariwa — largest by capacity in the world, offline since 2012 for safety review.
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China
Full country profile →
Tianwan — China has more reactors under construction than any other country (20+ units).
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UAE
Full country profile →
Barakah — the Arab world's first nuclear plant, built by Korea's KEPCO, fully operational since 2024.
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Canada
Jump to Bruce Nuclear
Bruce Nuclear — the world's largest operating nuclear plant by capacity (6,430 MW).
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Ukraine
Jump to Zaporizhzhia
Zaporizhzhia — Europe's largest nuclear plant, under IAEA safety monitoring since 2022.
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South Korea
Jump to Hanul
Hanul and Hanbit — KEPCO's twin giants, two of the world's top 5 by capacity.
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France
Jump to Cattenom
Cattenom, Gravelines, and Paluel — 3 of the world's top 15 · France generates ~70% of its electricity from nuclear.
Prefer plants over countries? Jump straight to the world's largest nuclear power stations, GPS-located ↓
"The energy in uranium is the energy that forged the elements in stellar cores. Every atom of uranium on Earth was created in a supernova explosion billions of years before the solar system existed. When we split a uranium atom, we are releasing energy that was stored before the Earth was born. We are not creating energy. We are completing a story that began in a star."
— The Energy Codex · observation without separation · thecodex.expert
Cluster 1 · What is it?
What nuclear energy is — precisely
Nuclear energy is the energy stored in the nuclei of atoms — released either by splitting heavy atoms (fission) or by joining light atoms together (fusion). Both processes release energy because the resulting atoms weigh slightly less than the original atoms: that missing mass becomes energy, as described by Einstein's equation E = mc².
In plain English — fission: Inside every atom is a nucleus — a tiny, dense core. Some nuclei are unstable, especially very large ones like uranium. When a neutron (a tiny neutral particle) hits a uranium nucleus, the nucleus splits in two — releasing a burst of heat and 2–3 more neutrons. Those neutrons hit other uranium nuclei, splitting them, releasing more heat and more neutrons. This is a chain reaction. In a nuclear power plant, this chain reaction is carefully controlled to produce steady heat. That heat boils water, makes steam, and the steam spins a turbine that generates electricity — exactly like a coal power station, except the heat source is atoms splitting instead of coal burning. No carbon dioxide is released from the fission process.
The fission process in detail:
Fuel: Uranium-235 (U-235) — a naturally occurring isotope that makes up 0.7% of natural uranium (the rest is U-238, which is not fissile in a thermal reactor). Natural uranium is enriched to 3–5% U-235 for use in light water reactors. The fuel is formed into ceramic pellets, loaded into fuel rods, and arranged in bundles.
Chain reaction: A neutron strikes a U-235 nucleus → nucleus splits into two fission products (e.g., barium-144 + krypton-89) → releases 2–3 neutrons + 200 MeV of energy. Moderator (water or graphite) slows neutrons to the speed needed for efficient fission. Control rods (boron or hafnium) absorb neutrons — inserting them slows or stops the reaction.
Why uranium is so energy-dense: E = mc². Even a tiny amount of mass converts to an enormous amount of energy (c = 3×10⁸ m/s — the speed of light). Fission releases approximately 8 million times more energy per reaction than burning a carbon atom.
Fuel: Uranium-235 (U-235) — a naturally occurring isotope that makes up 0.7% of natural uranium (the rest is U-238, which is not fissile in a thermal reactor). Natural uranium is enriched to 3–5% U-235 for use in light water reactors. The fuel is formed into ceramic pellets, loaded into fuel rods, and arranged in bundles.
Chain reaction: A neutron strikes a U-235 nucleus → nucleus splits into two fission products (e.g., barium-144 + krypton-89) → releases 2–3 neutrons + 200 MeV of energy. Moderator (water or graphite) slows neutrons to the speed needed for efficient fission. Control rods (boron or hafnium) absorb neutrons — inserting them slows or stops the reaction.
Why uranium is so energy-dense: E = mc². Even a tiny amount of mass converts to an enormous amount of energy (c = 3×10⁸ m/s — the speed of light). Fission releases approximately 8 million times more energy per reaction than burning a carbon atom.
In a U-235 thermal fission event, the nucleus absorbs a thermal neutron (kinetic energy ~0.025 eV, corresponding to ~2000 m/s) and undergoes compound nucleus formation (U-236*) before splitting. The binding energy per nucleon peaks at iron-56 — fission of heavy nuclei and fusion of light nuclei both release energy by moving toward this maximum. Average energy released per fission: ~200 MeV total (kinetic energy of fission fragments ~168 MeV, neutrons ~5 MeV, gamma rays ~7 MeV, beta decay ~20 MeV). Thermal reactor criticality is governed by the four-factor formula: k∞ = η × ε × p × f (reproduction factor × fast fission factor × resonance escape probability × thermal utilisation). Enrichment: commercial LWRs use 3–5% U-235. HEU (highly enriched uranium, >20% U-235) is restricted under the Nuclear Non-Proliferation Treaty. The moderator-to-fuel ratio in LWRs creates a negative temperature coefficient of reactivity — if the core overheats, reactivity decreases, providing inherent physical safety feedback.
Source: Lamarsh & Baratta, "Introduction to Nuclear Engineering" (Pearson) · US NRC — Fission basics
3,900,000 MJ/kgUranium energy density — highest of any practical fuel
12 g CO₂/kWhLifecycle emissions — lowest of all energy sources (IPCC AR6)
~90%Typical capacity factor — runs nearly continuously
440Reactors operating in 32 countries (IAEA 2024)
10%Share of global electricity (IEA 2024)
Cluster 5 · Energy density — putting it in perspective
Why uranium's energy density matters
Energy density — how much energy is stored per kilogram of fuel — determines land use, fuel logistics, and waste volumes. Uranium's energy density is so extreme that it has no practical parallel among fuels.
Note: uranium bar is at 100% scale — all other bars are proportionally correct but invisible at this scale, illustrating the magnitude of the difference. Source: World Nuclear Association — Heat Values of Fuels · IPCC AR6
What this means in practice
A 1,000 MW nuclear plant requires approximately 27 tonnes of uranium fuel per year. The same electricity from coal would require approximately 3 million tonnes of coal per year — 100,000 times more material to mine, transport, and burn. A 1,000 MW nuclear plant's annual waste (spent fuel) fills approximately one standard shipping container. A coal plant producing the same electricity produces approximately 3 million tonnes of CO₂ and hundreds of thousands of tonnes of ash, plus air pollutants. The extreme energy density of uranium is the single most important physical fact about nuclear energy.
Cluster 3 · Reactor types
Every reactor type — how each works
PWR — Pressurised Water Reactor 70% of fleet
The most common reactor type globally. Two water loops: the primary loop at very high pressure (155 bar) prevents water from boiling at 320°C. This hot pressurised water heats a secondary loop (via steam generator) which boils to drive the turbine. The radioactive primary water never contacts the turbine. Used in: USA, France, China, Russia, South Korea, UAE. Examples: Barakah (UAE), Vogtle (USA).
BWR — Boiling Water Reactor ~15% of fleet
Simpler than PWR — water boils directly in the reactor vessel and the steam drives the turbine directly. Lower pressure than PWR (~75 bar). No steam generator needed. Disadvantage: some radioactive steam enters the turbine. Used in: USA, Japan, Sweden. Examples: Fukushima Daiichi (accident 2011), Clinton Power Station (USA).
PHWR — Pressurised Heavy Water Reactor India's primary type
Uses heavy water (deuterium oxide, D₂O) as both moderator and coolant. Key advantage: can use natural uranium (no enrichment needed), making it independent of enrichment technology. Canada's CANDU (Canadian Deuterium Uranium) design. India's INDU design. 49 PHWRs operating globally. Used in: Canada, India, South Korea, Argentina, Romania, Pakistan. India's 700 MW PHWR units are being deployed as the mainstay of India's nuclear programme.
RBMK — Graphite-moderated Channel Reactor Russia only · legacy
Soviet design using graphite as moderator and water as coolant. Positive void coefficient (dangerous: if coolant boils, reactivity increases) — the design flaw that contributed to the 1986 Chernobyl accident. No longer built. Remaining RBMK units operate in Russia with significant safety upgrades since 1986. The Chernobyl plant was an RBMK-1000.
Small Modular Reactors (SMRs) Under development
Factory-built reactors under 300 MW — designed for standardised manufacturing, reduced construction time, and deployment in locations too small for conventional plants. Key designs: NuScale VOYGR (USA, 77 MW modules), Rolls-Royce SMR (UK, 470 MW), BWRX-300 (GE Hitachi, 300 MW), Kairos KP-FHR (molten salt). First commercial SMR: Ontario Power Generation's BWRX-300 at Darlington, Canada, targeting 2034. India's NPCIL is developing indigenous SMR designs.
Generation IV reactors — next designs Future
Six reactor concepts under international development (Generation IV International Forum): Very High Temperature Reactor (VHTR), Supercritical Water Reactor (SCWR), Gas-Cooled Fast Reactor (GFR), Lead-Cooled Fast Reactor (LFR), Molten Salt Reactor (MSR), Sodium-Cooled Fast Reactor (SFR). Key advantages: improved fuel efficiency (some can use spent nuclear fuel), inherent safety features, and higher operating temperatures. China's HTR-PM (400 MW, pebble bed) is the first Gen IV plant to come online (2021). Source: Generation IV International Forum
Cluster 13 · Named instances — major nuclear plants
The world's largest nuclear power stations — every one located
| # | Plant name | Country | GPS | Capacity | Type | Operator / status |
|---|---|---|---|---|---|---|
| 1 | Kashiwazaki-Kariwa | Japan | 37.42°N 138.60°E | 7,965 MW (7 units) | BWR | Tokyo Electric Power (TEPCO) · Offline 2012 for safety review · Largest by capacity if operational |
| 2 | Bruce Nuclear | Canada | 44.33°N 81.60°W | 6,430 MW (8 units) | PHWR/CANDU | Bruce Power · Lake Huron, Ontario · Largest operational nuclear plant in the world · Refurbishment ongoing |
| 3 | Zaporizhzhia | Ukraine | 47.51°N 34.59°E | 6,000 MW (6 units) | PWR/VVER | Energoatom · Under IAEA safety monitoring since 2022 · Europe's largest nuclear plant |
| 4 | Hanul (Ulchin) | South Korea | 37.09°N 129.38°E | 5,928 MW (6 units) | PWR (APR1000) | KEPCO · East coast of South Korea · Operating since 1988 |
| 5 | Hanbit (Yonggwang) | South Korea | 35.41°N 126.42°E | 5,875 MW (6 units) | PWR | KEPCO · West coast of South Korea |
| 6 | Cattenom | France | 49.41°N 6.22°E | 5,200 MW (4 units) | PWR (1,300 MW each) | EDF · Moselle River · France generates ~70% of electricity from nuclear |
| 7 | Gravelines | France | 50.96°N 2.13°E | 5,460 MW (6 units) | PWR (910 MW each) | EDF · North Sea coast · Largest nuclear plant by unit count in France |
| 8 | Paluel | France | 49.86°N 0.63°E | 5,320 MW (4 units) | PWR (1,330 MW each) | EDF · English Channel coast · Normandy |
| 9 | Palo Verde | USA | 33.39°N 112.86°W | 3,942 MW (3 units) | PWR | Arizona Public Service · Largest nuclear plant in the USA by capacity |
| 10 | Vogtle Built ✓ | USA | 33.14°N 81.76°W | 4,664 MW (4 units) | PWR (AP1000) | Georgia Power · Units 3 and 4 (Westinghouse AP1000) completed 2023–24 — first new US nuclear units in 30+ years |
| 11 | Tianwan | China | 34.68°N 119.46°E | 6,117 MW (6 units op. + 2 building) | PWR (VVER-1000) | JNPC · Jiangsu province · Russia-China partnership · China has most reactors under construction globally (20+ units) |
| 12 | Barakah | UAE | 23.96°N 52.20°E | 5,600 MW (4 units) | PWR (APR1400) | ENEC · Abu Dhabi · Arab world's first nuclear plant · Built by Korean KEPCO · All 4 units operational by 2024 |
| 13 | Kudankulam Built ✓ | India | 8.17°N 77.72°E | 2,000 MW op. + 4,000 MW planned (6 units total) | PWR (VVER-1000) | NPCIL · Tamil Nadu · Russia-India partnership · Units 1 and 2 operational · Units 3–6 under construction |
| 14 | Tarapur Atomic Power Station | India | 19.83°N 72.66°E | 1,400 MW (4 units) | BWR + PHWR | NPCIL · Maharashtra · India's oldest nuclear plant (1969) · First 2 units: GE BWRs; Later 2 units: 540 MW PHWRs |
| 15 | ITER | France | 43.69°N 5.77°E | 500 MW fusion (planned) | Tokamak fusion | ITER Organisation (35 nations) · Cadarache · Under assembly · $22 billion · First plasma target 2025 · Full fusion power 2035+ |
GPS: IAEA Power Reactor Information System (PRIS) · WRI GPPD (CC BY 4.0)
Cluster 3 · Fusion energy · ITER
Fusion — recreating the sun's engine on Earth
Fusion in plain English: The sun shines by fusing hydrogen atoms together — smashing them so hard that they combine into helium, releasing enormous energy. Scientists have been trying to do this on Earth for 70 years. The challenge: to fuse hydrogen, you need temperatures of 100–150 million degrees Celsius — hotter than the core of the sun. At these temperatures, the hydrogen becomes a plasma (a superheated cloud of electrically charged particles). You cannot put it in a container — it would melt anything. So scientists use powerful magnetic fields to suspend the plasma inside a doughnut-shaped chamber called a tokamak. Fusion energy, if achieved at scale, would be effectively limitless — the fuel (hydrogen isotopes) is abundantly available in seawater — and produces no carbon dioxide and far less radioactive waste than fission.
Fusion reaction: Deuterium (D) + Tritium (T) → Helium-4 + neutron + 17.6 MeV. Deuterium is abundant in seawater (~1 in 6,400 hydrogen atoms). Tritium is rare — it is produced by bombarding lithium-6 with neutrons (conveniently provided by the fusion reaction itself in a "breeding blanket"). ITER will not breed tritium; that technology is planned for the demonstration plant DEMO.
ITER (GPS: 43.69°N 5.77°E): International Thermonuclear Experimental Reactor, Cadarache, France. 35-nation project: EU, USA, Russia, China, India, Japan, South Korea. Cost: ~$22 billion. Tokamak plasma volume: 840 m³. Plasma temperature: 150 million °C. Target: Q=10 (produce 10 times the energy input). ITER will not generate electricity — it is a scientific experiment to prove fusion works at scale. The commercial demonstration plant (DEMO) is planned for the 2040s.
ITER (GPS: 43.69°N 5.77°E): International Thermonuclear Experimental Reactor, Cadarache, France. 35-nation project: EU, USA, Russia, China, India, Japan, South Korea. Cost: ~$22 billion. Tokamak plasma volume: 840 m³. Plasma temperature: 150 million °C. Target: Q=10 (produce 10 times the energy input). ITER will not generate electricity — it is a scientific experiment to prove fusion works at scale. The commercial demonstration plant (DEMO) is planned for the 2040s.
Source: ITER Organisation · IAEA — Fusion
The Lawson criterion defines the conditions for fusion ignition: nτE × T ≥ 3×10²¹ m⁻³·s·keV (ion temperature), where n is plasma density, τE is energy confinement time, and T is temperature. ITER aims for Q=10 (fusion power output = 10× heating power input), producing 500 MW fusion power from 50 MW input, with plasma current 15 MA and magnetic field 5.3 T. The tokamak's superconducting magnets (Nb₃Sn and NbTi) require cooling to 4K (liquid helium). ITER's 18 toroidal field coils are the largest superconducting magnets ever built. Private fusion companies (Commonwealth Fusion Systems, TAE Technologies, Helion Energy, General Fusion) are pursuing commercial fusion on accelerated timelines using high-temperature superconductors (HTS), alternative confinement geometries (stellarators, inertial confinement, field-reversed configurations), and venture capital funding. Commonwealth Fusion has demonstrated a 20T HTS magnet — enabling a much smaller SPARC tokamak targeting first fusion energy in 2025.
Source: ITER — Scientific Goals · Nature Energy, "Commonwealth Fusion Systems 20T magnet" (2021)
Cluster 2 · Q9 · India and nuclear energy
India's nuclear programme — 70 years of indigenous development
India's nuclear capacity and unique strategy
India's installed nuclear capacity: approximately 7,480 MW from 24 operating reactors as of 2024, generating approximately 3% of India's electricity. India has a unique three-stage nuclear programme designed to maximise use of its large thorium reserves (one of the world's largest):
Stage 1: PHWRs using natural uranium — currently operational. Produces plutonium as a by-product.
Stage 2: Fast Breeder Reactors (FBRs) using plutonium from Stage 1 — breed more fuel than they consume. India's 500 MW Prototype Fast Breeder Reactor (PFBR) at Kalpakkam (GPS: 12.55°N 80.16°E) is under final commissioning (2024).
Stage 3: Thorium-232 based reactors — India has approximately 846,000 tonnes of thorium (one of the world's largest deposits). Long-term energy independence.
Source: Department of Atomic Energy, Government of India
Stage 1: PHWRs using natural uranium — currently operational. Produces plutonium as a by-product.
Stage 2: Fast Breeder Reactors (FBRs) using plutonium from Stage 1 — breed more fuel than they consume. India's 500 MW Prototype Fast Breeder Reactor (PFBR) at Kalpakkam (GPS: 12.55°N 80.16°E) is under final commissioning (2024).
Stage 3: Thorium-232 based reactors — India has approximately 846,000 tonnes of thorium (one of the world's largest deposits). Long-term energy independence.
Source: Department of Atomic Energy, Government of India
India's major nuclear plants
Kudankulam, Tamil Nadu · 8.17°N 77.72°E · 2,000 MW operational (Units 1–2) · VVER-1000 (Russia-India) · Units 3–6 under construction (4,000 MW more) · Operator: NPCIL
Tarapur, Maharashtra · 19.83°N 72.66°E · 1,400 MW · India's oldest nuclear plant (1969) · First 2 units: GE BWRs (USA design) · Later 2 units: 540 MW PHWRs
Rajasthan Atomic Power Station (RAPS) · 24.88°N 75.59°E · 1,180 MW (4 PHWR units) · Rawatbhata, Rajasthan · NPCIL
Madras Atomic Power Station (MAPS) · 12.55°N 80.17°E · 440 MW (2 PHWR units) · Kalpakkam · Site of India's Fast Breeder Reactor
India's target: 22,480 MW by 2031–32 (triple current capacity) · Requires significant new project commissioning. Source: NPCIL · DAE India
Tarapur, Maharashtra · 19.83°N 72.66°E · 1,400 MW · India's oldest nuclear plant (1969) · First 2 units: GE BWRs (USA design) · Later 2 units: 540 MW PHWRs
Rajasthan Atomic Power Station (RAPS) · 24.88°N 75.59°E · 1,180 MW (4 PHWR units) · Rawatbhata, Rajasthan · NPCIL
Madras Atomic Power Station (MAPS) · 12.55°N 80.17°E · 440 MW (2 PHWR units) · Kalpakkam · Site of India's Fast Breeder Reactor
India's target: 22,480 MW by 2031–32 (triple current capacity) · Requires significant new project commissioning. Source: NPCIL · DAE India
Cluster 7 · The companies
Who builds and operates nuclear energy
Ed
EDF (Électricité de France)
France · State-owned · Founded 1946
Operates France's entire nuclear fleet — 56 reactors, approximately 63 GW, generating approximately 70% of France's electricity. The most nuclear-dependent large economy in the world. CEO: Luc Rémont. Building 6 new EPR2 reactors (1,700 MW each) announced 2022. France's nuclear programme is the largest in the world relative to national electricity supply. EDF is also a major renewable operator — not just nuclear. Source: EDF Annual Report 2023
Ro
Rosatom
Russia · State corporation · Founded 2007
Russia's state nuclear corporation — covers the entire nuclear cycle from uranium mining to reactor design, construction, and waste management. CEO: Alexey Likhachev. Operates 37 reactors in Russia generating approximately 20% of Russian electricity. Has export contracts in approximately 35 countries — including India's Kudankulam (VVER-1000), Bangladesh Rooppur, Egypt El Dabaa, UAE Barakah, Turkey Akkuyu. The world's largest nuclear construction company by backlog. Source: Rosatom Annual Report 2023
NP
NPCIL
India · Government enterprise · Founded 1987
Nuclear Power Corporation of India Limited — India's sole nuclear power utility. Founded 1987 under the Atomic Energy Act. CEO/CMD: B.C. Pathak. Operates 24 reactors (7,480 MW). Under construction: Kudankulam 3–6, Gorakhpur Haryana, Rajasthan RAPP-7&8. Developing India's first SMR design. India's nuclear programme is unusual globally in its emphasis on indigenous technology (PHWR design) and the three-stage thorium cycle. Source: NPCIL Annual Report 2023
Ke
KEPCO
South Korea · State majority · Seoul · Founded 1961
Korea Electric Power Corporation — operates South Korea's 26 reactors (26,300 MW, generating ~30% of South Korean electricity). Built the UAE's Barakah plant (4 × APR1400, 5,600 MW) — the first export of a complete nuclear power plant by an Asian country. CEO: Kim Dong-cheol. South Korea's APR1400 design is among the world's most competitive in cost and construction time. Source: KEPCO Annual Report 2023
We
Westinghouse Electric
USA · Founded 1886 · Now private equity owned
Founded 1886 by George Westinghouse — who also backed Tesla's AC system. Built the world's first pressurised water reactor. The AP1000 design (1,117 MW) was selected for the Vogtle Units 3&4 (USA) — first new US nuclear units in 30+ years. AP1000 also deployed in China (Sanmen, Haiyang). The AP1000 features passive safety systems that cool the reactor for 72 hours without any operator action or external power — a significant post-Fukushima safety advance. Source: Westinghouse Nuclear
GP
Georgia Power
USA · Southern Company subsidiary · Founded 1883
Traces to the Georgia Electric Light Company of Atlanta (1883); incorporated in its current form in 1930 as a Southern Company subsidiary. Chairman, President & CEO: Kim Greene (since 2023). Owner-operator of Plant Vogtle — Units 3 & 4 are the first new US reactors built in over 30 years, using Westinghouse's AP1000 design, reaching commercial operation in July 2023 and April 2024 after a total project cost exceeding $35 billion. Serves more than 2.8 million customers with roughly 6,800 employees. Source: Georgia Power — Plant Vogtle
IT
ITER Organization
France · International · Founded 2007
Intergovernmental organization established 24 October 2007 to build the world's largest experimental fusion reactor (tokamak) at Cadarache, southern France. Seven members — China, the European Union, India, Japan, Korea, Russia, and the United States — jointly fund and supply components, representing 35 nations in total. A pure research project: ITER will never sell electricity to the grid. Costs have grown well beyond the original ~$10 billion estimate, and first-plasma targets have slipped from the 2020s into the mid-2030s. Source: ITER Organization
CF
Commonwealth Fusion Systems
USA · Private · Founded 2018 · MIT spinout
MIT spinout company founded by nuclear physicist Dennis Whyte and colleagues. Raised over $1.8 billion to build SPARC — a compact tokamak using high-temperature superconducting magnets. In 2021, CFS demonstrated a 20 Tesla HTS magnet — the world's most powerful superconducting magnet for fusion — enabling a much smaller and faster route to fusion energy than ITER. Targets first fusion energy from SPARC by 2025, commercial plant (ARC) by early 2030s. Source: CFS Energy · Nature Energy (2021)
Cluster 4 · Q15 · The pioneers
The people who created nuclear energy
Enrico Fermi · 1901–1954 · First controlled nuclear chain reaction
On 2 , beneath the stands of Stagg Field stadium at the University of Chicago, Italian-American physicist Enrico Fermi achieved the first controlled, self-sustaining nuclear chain reaction. "Chicago Pile-1" used 40,000 kg of uranium and 385 tonnes of graphite. The reaction ran at a maximum power of 200 watts — enough to power a light bulb. Fermi was the first person to deliberately and controllably release nuclear energy. Every nuclear power plant on Earth is the direct descendant of this experiment. Fermi won the Nobel Prize in Physics in 1938 for work on neutron bombardment. Source: US Department of Energy Historical Records.
Homi Bhabha · 1909–1966 · Architect of India's nuclear programme
Homi Jehangir Bhabha founded the Tata Institute of Fundamental Research (1945) and the Atomic Energy Establishment (later BARC — Bhabha Atomic Research Centre) in Mumbai. He designed India's three-stage nuclear programme — using India's modest uranium resources to breed plutonium, then using India's vast thorium reserves for long-term energy independence. India's nuclear strategy for the next century traces directly to his 1954 blueprint. He died in an Air India crash on Mont Blanc in 1966 at age 56. The Bhabha Atomic Research Centre (BARC) at Trombay, Mumbai (19.01°N 72.92°E) bears his name. Source: BARC India · DAE India
Alvin Weinberg · 1915–2006 · Invented the PWR and warned of its limits
Alvin Weinberg co-invented the pressurised water reactor (PWR) at Oak Ridge National Laboratory — the design now used in approximately 70% of the world's nuclear fleet. He also invented the light water reactor's basic design in 1946. Later in his career, Weinberg became an outspoken advocate for nuclear safety and publicly warned about the difficulties of managing nuclear waste over geological time periods — a concern that contributed to his removal as director of Oak Ridge. He also pioneered the Molten Salt Reactor (MSR) concept in the 1960s, which is now being revived as a Generation IV reactor type. Source: Weinberg, A.M. (1994) "The First Nuclear Era" (AIP Press).
Rickover & the Navy · 1906–1986 · Nuclear propulsion made nuclear power practical
Admiral Hyman Rickover led the development of the first nuclear-powered submarine (USS Nautilus, 1954) and the first civilian nuclear power plant at Shippingport, Pennsylvania (1958). Rickover's engineering rigour — demanding exhaustive documentation, training, and discipline for anyone working with naval reactors — established the safety culture that civilian nuclear power inherited. He supervised the US Navy's nuclear programme for 30 years, building a fleet of nuclear submarines and aircraft carriers that operated without a single reactor accident. His insistence on conservative engineering and deep technical competence remains the gold standard for nuclear operations. Source: US Naval Institute.
Cluster 5 · What nuclear energy has given the world
What this energy built
France — 70% nuclear, lowest carbon grid in Europe
France generates approximately 70% of its electricity from nuclear energy — the highest share of any large economy — and as a result has one of the lowest carbon intensities of electricity in Europe: approximately 85 g CO₂/kWh (vs 400+ g for Germany, which reduced nuclear and increased gas). France has exported electricity to neighbours for decades, earning revenue while providing clean baseload power to the European grid. Nuclear gave France energy independence from oil and gas. Source: RTE France · IEA
Medicine — nuclear isotopes saving millions of lives
Nuclear reactors produce medical isotopes used in diagnostic imaging and cancer treatment. Technetium-99m — produced in reactors — is used in approximately 40 million medical procedures globally every year for bone scans, heart imaging, and tumour detection. Cobalt-60 from reactors powers radiotherapy machines treating cancer in approximately 60 countries. Iodine-131 is used to treat thyroid cancer. The medical benefit of nuclear reactors is rarely discussed alongside their energy generation role. Source: IAEA — Nuclear Medicine
South Korea — nuclear powered industrialisation
South Korea's rapid industrialisation from the 1970s was partly enabled by nuclear energy providing reliable, low-cost baseload electricity. South Korea now generates approximately 30% of its electricity from 26 nuclear reactors — and has built one of the world's most competitive nuclear industries (KEPCO's APR1400 design won the UAE contract over US, French, and Japanese competitors). Nuclear powered the steel mills, shipyards, and semiconductor fabs that made South Korea an industrial powerhouse. Source: KEPCO · World Nuclear Association
Cluster 11 · The future of nuclear
What institutional sources project
SMRs — the next generation of nuclear
Small Modular Reactors (SMRs) below 300 MW offer potential advantages over large conventional plants: factory manufacturing (cost reduction via economies of scale in production, not in size), shorter construction timelines (3–4 years vs 10–20 for large plants), and deployment in remote locations and smaller grids. First commercial SMR projects: Ontario Power Generation BWRX-300 (Darlington, Canada, targeting 2034), Rolls-Royce SMR (UK, targeting 2035). India's NPCIL is developing indigenous SMR designs under the three-stage programme. However, per-kW costs of SMRs may be higher than large plants due to loss of economies of scale — the economic case is not yet proven at commercial scale. Source: IAEA · IEA · World Nuclear Association
Fusion energy timeline — what the science shows
ITER targets first plasma in 2025 and full fusion power demonstration in the 2035–2039 timeframe. The follow-on DEMO (demonstration power plant) is planned for the 2040s. Private fusion companies (Commonwealth Fusion Systems, Helion Energy, TAE Technologies, General Fusion) target commercial fusion by the early 2030s — ambitious but backed by over $5 billion in private investment.
The physics of fusion is solved — it has been demonstrated in dozens of experiments. The engineering challenge is sustaining it reliably and cheaply enough to be commercially viable. The ITER project's job is to prove Q>1 (more energy out than in) at power-plant scale. Source: ITER Organisation · Fusion Industry Association
The physics of fusion is solved — it has been demonstrated in dozens of experiments. The engineering challenge is sustaining it reliably and cheaply enough to be commercially viable. The ITER project's job is to prove Q>1 (more energy out than in) at power-plant scale. Source: ITER Organisation · Fusion Industry Association
Cluster 12 · Reader questions
Six questions people actually ask — answered
How does nuclear energy work?
Nuclear fission works by splitting uranium-235 atoms. A neutron strikes a uranium nucleus, splitting it in two and releasing heat plus 2–3 more neutrons. Those neutrons split more uranium — a chain reaction. The heat boils water, makes steam, and steam spins a turbine and generator — exactly like a coal plant, except the heat source is atoms splitting instead of fuel burning. No CO₂ is released from the fission process. Control rods absorb neutrons to control the reaction speed. The reactor cannot explode like a bomb — the uranium fuel is not concentrated enough for a nuclear explosion; what can happen is a loss of cooling leading to a meltdown (which happened at Three Mile Island and Fukushima).
Source: IAEA — Nuclear Power Reactors · World Nuclear Association
Is nuclear energy safe?
Nuclear energy has the lowest death rate per unit of electricity produced of any major energy source — including renewable energy. The WHO and UNSCEAR have documented approximately 60 deaths directly attributable to radiation from the Chernobyl accident (31 immediate, ~19 thyroid cancer deaths). The 2011 Fukushima accident caused zero radiation deaths (one death from cancer in 2018 was classified as radiation-related). By comparison, air pollution from fossil fuels causes approximately 8.7 million premature deaths per year (WHO 2022). Coal mining and transport deaths per TWh are orders of magnitude higher than nuclear. However, major accidents (Chernobyl, Fukushima) cause large-scale displacement and lasting public concern. Nuclear's safety record in objective data is strong — but so is the public's right to understand and weigh the risks. Source: WHO · UNSCEAR · Lancet (energy death rates).
Source: WHO · UNSCEAR 2022 Report · Sovacool et al., Lancet 2021 (energy death rates)
What is the nuclear waste problem?
Nuclear power produces three categories of waste. Low and intermediate level waste (contaminated tools, clothing, components) is the bulk by volume and is managed routinely. High-level waste (spent nuclear fuel) is the critical challenge — it is highly radioactive and some components remain dangerous for tens of thousands of years. However, the total volume is small: all the spent nuclear fuel produced by the US nuclear fleet since 1957 would fit in a football field 10 metres deep. Finland is building the world's first permanent deep geological repository (Onkalo, planned to open 2025) — sealing spent fuel in copper canisters 400 metres underground in granite rock. Sweden and France are building similar facilities. Source: IAEA · Finnish Radiation and Nuclear Safety Authority (STUK).
Source: IAEA Nuclear Waste Management · STUK Finland · WNA — Nuclear Waste Management
How much nuclear energy does India have?
India has approximately 7,480 MW of nuclear capacity from 24 operating reactors as of 2024 — generating approximately 3% of India's electricity. India's nuclear programme is unusual: it follows a unique three-stage strategy to use India's large thorium deposits (one of the world's largest). Stage 1 (current): PHWRs on natural uranium. Stage 2 (beginning): Fast Breeder Reactors breeding plutonium from Stage 1. Stage 3 (future): Thorium-based reactors. India's largest plant is Kudankulam (Tamil Nadu) at 2,000 MW (with 4,000 MW more under construction). India's target is 22,480 MW by 2031–32. Source: NPCIL · DAE Government of India 2024.
Source: Nuclear Power Corporation of India (NPCIL) · Department of Atomic Energy (DAE), 2024
What is the difference between nuclear fission and fusion?
Fission splits heavy atoms (uranium, plutonium). Fusion joins light atoms (hydrogen isotopes). Both release energy because the resulting atoms weigh less than the inputs — the missing mass becomes energy via E=mc². All current nuclear power plants use fission. Fusion is what powers the sun and hydrogen bombs, but has not yet been achieved in a controlled, energy-positive way at power-plant scale. Fusion's potential advantages: far more abundant fuel (hydrogen from seawater), no long-lived radioactive waste (the main product is helium), and no risk of a meltdown. The challenge is the extreme conditions required (150 million °C). ITER in France is the world's largest experiment to demonstrate fusion works at scale. Source: IAEA · ITER Organisation.
Source: IAEA · ITER Organisation · World Nuclear Association
How much does nuclear electricity cost?
Nuclear electricity costs depend critically on whether a plant is new or already built. Existing nuclear plants generate electricity very cheaply — often $20–30/MWh — because the capital cost is already paid. New nuclear is expensive: Lazard's 2024 LCOE analysis puts new nuclear at $141–221/MWh, making it among the most expensive new electricity sources. High upfront capital cost, long construction timelines (10–20 years for large plants), and financing costs are the main drivers. South Korea's KEPCO builds nuclear at significantly lower cost (~$2,500–3,500/kW vs $7,000–12,000/kW in the USA and UK) due to standardised design and sustained construction. SMRs aim to reduce costs through factory manufacturing — not yet proven at commercial scale. Source: Lazard LCOE 2024 · IEA · World Nuclear Association.
Source: Lazard LCOE Analysis 2024 · IEA Nuclear Power and Secure Energy Transitions 2022
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Every source used on this page
Primary sources — all public, all free to verify
IAEA PRISPower Reactor Information System · 440 reactors · GPS, capacity, status, country datapris.iaea.org
IEANuclear Power and Secure Energy Transitions 2022 · Renewables 2024 · WEO 2024iea.org/nuclear-power-and-secure-energy-transitions
World Nuclear AssociationReactor data · Nuclear fuel cycle · Heat values of fuels · Safety statisticsworld-nuclear.org
WRI GPPDGlobal Power Plant Database · GPS coordinates · CC BY 4.0datasets.wri.org/globalpowerplantdatabase
LazardLevelised Cost of Energy Analysis 2024 · Nuclear LCOE $141–221/MWhlazard.com/levelized-cost-of-energy
IPCC AR6Lifecycle emissions · Nuclear 12 g CO₂/kWh — lowest of all sourcesipcc.ch/report/ar6/wg3
ITER OrganisationITER project specifications · Fusion science goals · Construction statusiter.org
NPCIL IndiaNuclear Power Corporation of India · Reactor fleet · Three-stage programmenpcil.nic.in
DAE IndiaDepartment of Atomic Energy · India nuclear policy · Thorium programmedae.gov.in
BARC IndiaBhabha Atomic Research Centre · Homi Bhabha history · Indian reactor designbarc.gov.in
Generation IV Int. ForumGen IV reactor concepts · Technology readiness levelsgen-4.org
EDFAnnual Report 2023 · France nuclear fleet · New EPR2 programmeedf.fr/investors
KEPCOAnnual Report 2023 · South Korea nuclear fleet · UAE Barakahkepco.co.kr/EN
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- The Codex (Let Us Do It For U), Mumbai, India · hello@thecodex.expert
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- concept · High — Tier-1 sources (IEA, IRENA, IPCC AR6), verified
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- "The Energy Codex", https://thecodex.expert/energy/nuclear/, last updated .