A line chart showing the development of operational nuclear reactors worldwide from 1954 to 2023. At the end of 2023, there were 413 operational nuclear reactors worldwide, with an increase compared to the previous year. In 2023, the  construction of six new nuclear power plants began globally. In 1959, there were just 11 operable reactors, and within 30 years the number had shot up to 420. Since 1989, reactor numbers have remained relatively stable, peaking at 450 in 2018.