Global nuclear reactor median construction time 1981-2022

Nuclear reactors connected to the grid in 2022 had a median construction time of 89 months or almost 7.5 years. During the period in consideration, the median construction time for nuclear reactors was the longest for reactors connected between 1996 and 2000, at 120 months.

Nuclear reactors with longest construction time

In 2022, Finland’s Olkiluoto 3 and France’s Flamanville 3 were the world’s nuclear reactors with the longest actual construction time compared to the projected schedule. Olkiluoto 3 was connected to the grid in 2022 after 101 months of construction works.

Nuclear reactors under construction worldwide

More than one-third of the nuclear units under construction globally as of 2023 were located in China, which also recorded the lowest mean construction time for nuclear reactors worldwide. By comparison, the construction time for reactors in the United States averaged almost 43 years, or seven times the same value in China.