U.S. Nuclear Reactors Among the Oldest in the World

By Katharina Buchholz

2022.11.27

The United States’ 92 nuclear reactors currently in operation have a mean age of 41.6 years, the third oldest in the world. The only nuclear fleets that are older are those of Switzerland (46.3 years) and Belgium (42.3 years). Also older are the singular reactors in use in Armenia and the Netherlands.

The U.S. was among the first commercial adopters of nuclear energy in the 1950s, explaining the number of aging reactors today. A building boom between the 1960s and 1970s created today’s nuclear power plants in the United States. The five reactors completed in the 1990s and the one finished in 2016 were all holdovers of delayed construction projects from the 1970s experiencing roadblocks due to regulatory problems and mounting opposition to nuclear energy. The most recent construction start date of a completed U.S. reactor today is 1978 – one year before the nuclear accident at Three Mile Island, which further cemented the public’s rejection of nuclear energy and the challenges of updating nuclear reactor infrastructure today. However, two reactors started at Vogtle power plant in Georgia in 2013 will join the grid soon as the newest additions to the U.S. fleet. They too experienced many regulatory and other delays, culminating in the bankruptcy of the reactor construction company. The U.S. government stepped in with a loan so that the project can now be finished almost 17 years after its initial proposal.