# Nuclear Energy — The Complete Guide
## The Energy Codex · thecodex.expert/energy/nuclear/
**Last verified:** April 2026 | **Session:** 9 (2026-04-27)

## Key Facts
| Metric | Value | Source |
|--------|-------|--------|
| Reactors operating | 440 in 32 countries | IAEA PRIS 2024 |
| Total capacity | ~395 GW | IAEA PRIS 2024 |
| Share of global electricity | ~10% | IEA 2024 |
| Lifecycle carbon | 12 g CO₂/kWh | IPCC AR6 — lowest of all |
| Uranium energy density | 3,900,000 MJ/kg | World Nuclear Association |
| New nuclear LCOE | $141–221/MWh | Lazard 2024 |
| ITER location | 43.69°N 5.77°E, France | ITER Organisation |
| ITER cost | $22 billion, 35 nations | ITER Organisation |

## Energy Density Comparison
Uranium: 3,900,000 MJ/kg | Hydrogen: 142 MJ/kg | Petrol: 46 MJ/kg | Coal: 24 MJ/kg | Battery: 0.9 MJ/kg

## 6 Reactor Types
PWR (70% of fleet): Two water loops, 155 bar, 320°C — USA, France, China, Russia, Korea, UAE
BWR (~15%): Steam boils directly in vessel — USA, Japan, Sweden
PHWR: Heavy water moderator, natural uranium fuel — Canada (CANDU), India (INDU)
RBMK: Soviet graphite-water, positive void coefficient — Chernobyl type, legacy Russia only
SMR: Factory-built <300MW — NuScale/Rolls-Royce/BWRX-300, first commercial 2034 (Canada)
Gen IV: VHTR/MSR/SFR/LFR etc — China HTR-PM online 2021 (first Gen IV)

## 15 Major Plants (GPS from IAEA PRIS + WRI GPPD)
| # | Name | Country | GPS | MW | Type |
|---|------|---------|-----|----|------|
| 1 | Kashiwazaki-Kariwa | Japan | 37.42°N 138.60°E | 7,965 | BWR (offline) |
| 2 | Bruce Nuclear | Canada | 44.33°N 81.60°W | 6,430 | PHWR |
| 3 | Zaporizhzhia | Ukraine | 47.51°N 34.59°E | 6,000 | PWR |
| 4 | Hanul | South Korea | 37.09°N 129.38°E | 5,928 | PWR |
| 5 | Hanbit | South Korea | 35.41°N 126.42°E | 5,875 | PWR |
| 6 | Cattenom | France | 49.41°N 6.22°E | 5,200 | PWR |
| 7 | Gravelines | France | 50.96°N 2.13°E | 5,460 | PWR |
| 8 | Paluel | France | 49.86°N 0.63°E | 5,320 | PWR |
| 9 | Palo Verde | USA | 33.39°N 112.86°W | 3,942 | PWR |
| 10 | Vogtle | USA | 33.14°N 81.76°W | 4,664 | PWR/AP1000 |
| 11 | Tianwan | China | 34.68°N 119.46°E | 6,117 | PWR/VVER |
| 12 | Barakah | UAE | 23.96°N 52.20°E | 5,600 | PWR/APR1400 |
| 13 | Kudankulam | India | 8.17°N 77.72°E | 2,000 op | PWR/VVER |
| 14 | Tarapur | India | 19.83°N 72.66°E | 1,400 | BWR+PHWR |
| 15 | ITER (fusion) | France | 43.69°N 5.77°E | 500 planned | Tokamak |

## India
Capacity: ~7,480 MW from 24 reactors (2024) — ~3% of electricity
Three-stage programme: Stage1 PHWR (current) → Stage2 FBR (PFBR at Kalpakkam commissioning) → Stage3 Thorium
Thorium reserves: ~846,000 tonnes — one of world's largest deposits
Target: 22,480 MW by 2031-32
Source: NPCIL · DAE Government of India 2024

## Fusion / ITER
Reaction: D + T → He-4 + neutron + 17.6 MeV
ITER goal: Q=10 (500 MW fusion from 50 MW input)
First plasma target: 2025 | Full fusion: 2035+
Private fusion: CFS SPARC, Helion, TAE Technologies, General Fusion — $5bn+ invested
Source: ITER Organisation

## Sources
IAEA PRIS 2024 · IEA Nuclear 2022 · World Nuclear Association · WRI GPPD · Lazard LCOE 2024 · IPCC AR6 · ITER Organisation · NPCIL India · DAE India · BARC India · Gen IV Forum · EDF · KEPCO