The nuclear fleet and the fuel chain behind it
NuclearChain tracks every nuclear reactor on Earth — operating, under construction, or retired — and the fuel chain of mines, converters, enrichers and fabricators that supplies it, alongside the naval reactors, weapons stockpiles, fusion projects and accidents that sit outside the civil fleet.
Reading today's US fleet availability…
Global Nuclear Power Tracker, Global Energy Monitor, August 2026 release · 1823 units tracked across 62 countries · fusion devices excluded from these totals
The fleet
Every unit ever built, building, or cancelled, 1823 of them, with specification, ownership and milestone dates.
The chain
Where the fuel comes from, and where it goes afterwards. Nine stages from mine to repository, and the handful of companies controlling each one.
The pipeline
Which SMR and advanced designs are actually moving through regulators, and which exist only in press releases.
Largest operating fleets
| Country | Units | GW gross |
|---|---|---|
| United States | 94 | 102.5 |
| China | 61 | 64.6 |
| France | 57 | 65.7 |
| Russia | 34 | 29.8 |
| South Korea | 26 | 27.1 |
| India | 22 | 8.4 |
| Canada | 17 | 13.5 |
| Ukraine | 15 | 13.8 |
Building now
| Country | Under construction |
|---|---|
| China | 36 |
| India | 8 |
| Russia | 7 |
| United States | 4 |
| Türkiye | 4 |
| South Korea | 4 |
How it works
Fission, moderators, decay heat, and why a reactor still needs cooling for years after it is switched off. Diagrams, no equations.
What it costs
Uranium, conversion, enrichment and fabrication indicators, forty years of price history, and a worked cost breakdown of one reactor core.
The raw data
Every table here as CSV and JSON, with the provenance of each field and the corrections applied on top of the source.
Beyond the civil fleet
Reactors that make electricity for a grid are only part of the picture. There are also 37 naval propulsion programmes running on fuel the civil chain never handles, an estimated 12,187 warheads held by 9 states whose fissile material came from the same enrichment and reprocessing plants, 24 fusion projects that have never delivered a watt to a grid, and 19 accidents that shaped every rule the rest of the industry now operates under. Each is kept on its own pages, with its own sources, and deliberately excluded from the fleet totals above.
Recent writing
- The reactor fleet is old, and only 36 units have a retirement date 193 of 419 operating reactors are 40 years old or more. The data on who retires when is thin: 36 units carry a planned retirement year, and licence expiry is not in the open dataset at all.
- Where the world's reactors sit: on the coast, on a lake, or inland Of 171 operating nuclear sites we can place precisely, 72 are on the sea and carry about 47% of the capacity. Here is how that splits by country, and what it does and does not tell you.
- Reactor type is not taxonomy, it is a different control problem Coolant and moderator decide how a plant behaves when something goes wrong: what the operator reaches for, which direction power moves on its own, and how fast it can be stopped.
All posts → · How this site is built, what it takes from where, and what it does not claim to know.
Common questions
- How many nuclear reactors are operating in the world?
- 419 nuclear reactors are operating in 32 countries, with a combined 405 GW gross capacity, according to the Global Nuclear Power Tracker August 2026 release.
- Which country has the most nuclear reactors?
- United States has the most operating reactors, 94, followed by China (61) and France (57).
- How many nuclear reactors are being built?
- 82 reactors are under construction, 88 GW gross in total. The countries building the most are China (36), India (8), Russia (7).
- What is the largest nuclear power plant in the world?
- Bruce nuclear power plant in Canada is the largest operating nuclear plant on record, with 8 units and 6.9 GW gross. See the largest plants ranked.
- Where does NuclearChain get its data?
- Reactor data comes from the Global Nuclear Power Tracker by Global Energy Monitor (August 2026 release, CC BY 4.0), with live US reactor status from the Nuclear Regulatory Commission. Every page lists its sources, and the datasets can be downloaded.