The 50 oldest nuclear reactors still operating in 2026
The 50 operating nuclear reactors with the most years since grid connection, among the 447 operating today.
The oldest nuclear reactor still operating is Tarapur 1, in India, connected in 1969: 57 years in service. 39 reactors connected before 1975 are still operating. By country, the veterans are mostly in United States (32), Russia (5) and India (3).
Data: Global Energy Monitor (CC BY 4.0), IAEA PRIS 2025, Wikipedia (CC BY-SA), Wikidata and Wikimedia Commons. Capacities in net MWe unless stated.
Other rankings
Under construction
Which reactors are being built in 2026, where and for when.
Largest plants
The plants with the most net capacity in operation.
Most powerful reactors
The units with the most MWe net in operation.
Recent connections
Reactors connected to the grid since 2021.
Shut down
The latest permanent closures and the announced restarts.
Ranking by country
Every country with nuclear power, by operating capacity.