Frequently Asked Questions

As of our latest data, there are 811 nuclear reactors tracked worldwide. This includes 439 operational reactors, 64 under construction, 81 planned, and 211 that have been permanently shut down. The data comes from the IAEA PRIS database.

The United States has the most nuclear reactors with 118 total, followed by France with 74 and China with 78. However, China is rapidly expanding its nuclear fleet with more reactors under construction than any other country.

The Pressurized Water Reactor (PWR) is by far the most common type, accounting for about 60% of all nuclear reactors worldwide (484 reactors). The Boiling Water Reactor (BWR) is the second most common with 120 reactors.

Our primary data source is the International Atomic Energy Agency's Power Reactor Information System (PRIS), the world's most comprehensive database of nuclear power reactors. We also enrich data with information from Wikidata and Wikipedia for operator details and descriptions.

We regularly sync our data with the IAEA PRIS database. Reactor status changes, new construction starts, and capacity updates are reflected as they become available from official sources.

Operational means the reactor is actively generating power. Under Construction means physical construction is underway. Planned means the project is approved but construction hasn't started. Suspended means work has been temporarily halted. Shutdown means the reactor is permanently closed. Cancelled means the project was terminated before completion.

Reactor capacity is measured in megawatts electrical (MWe), which represents the electrical power output. A typical modern reactor has a capacity between 1,000-1,400 MWe. The total global operational nuclear capacity is approximately 400 GW (gigawatts).

All modern reactor designs must meet strict international safety standards set by the IAEA. Newer Generation III and III+ designs like the AP1000, EPR, and APR1400 incorporate passive safety systems that don't require operator action or external power. The choice of reactor type depends on many factors beyond safety, including cost, efficiency, and fuel availability.

The 2011 Fukushima accident led several countries to reconsider their nuclear programs. Germany accelerated its phase-out, Japan temporarily shut down all reactors (many have since restarted), and new safety requirements were implemented globally. However, many countries continue to expand nuclear power as a low-carbon energy source.

The underlying reactor data comes from the IAEA PRIS database, which is publicly available. For academic or research purposes, we recommend citing the IAEA PRIS as the primary source. ReactorMap is an educational visualization tool built on this public data.

Some older or decommissioned reactors may have incomplete records in the IAEA database. Additionally, some enrichment data from Wikidata may not be available for all facilities. We display all available information and continuously work to improve data completeness.

Nuclear power provides about 10% of global electricity and is the second-largest source of low-carbon power after hydroelectric. A single reactor can power hundreds of thousands of homes and operates 24/7 regardless of weather conditions, unlike solar or wind power.