Most U.S. nuclear power plants were built between 1970 and 1990

As of 2016, the United States had 99 operating nuclear reactors at 61 plants across the country, with a capacity-weighted average age of 37 years. The oldest operating nuclear reactor in the United States was built in 1969. Watts Bar 2, which entered commercial service in 2016, was the first new reactor added since 1996. An additional four reactors are currently under construction. More »