Last week, Switzerland’s Axpo announced its intent to spend $400 million to extend the service life of Beznau, the country’s oldest NPP, for another 10 years until 2033. The first power unit of this NPP was put into operation in 1969, and the second one in 1972. As a result, the service life of the 760 MW NPP will reach 65 years by the end of 2033.
There is no maximum service life for NPPs in Swiss law: they can operate for as long as the operators can guarantee the safety of their power units as agreed upon with the regulator.
Until recently, more stringent requirements were in effect in Japan, where the basic service life of NPPs in 2013 was set at 40 years, after which power unit operators could request a one-time extension of operation for another 20 years. However, Japan’s Cabinet relaxed this rule last year. Today, operators will have to request permission to extend operation every 10 years upon reaching the 30-year term, although the number of such extensions will not be limited.
This easing was caused by the obsolescence of the NPP fleet. Japan’s oldest operating nuclear reactors are the first and second power units of the Takahama NPP, which came on stream in 1974 and 1975, respectively. While both units were suspended shortly after the Fukushima Daiichi accident, Japan’s Atomic Energy Agency granted permission to restart them last year, partly because they met the country’s strict seismic safety requirements (it is prohibited in Japan to use reactors sitting above active faults within Earth’s crust).
Economic feasibility also played a role. Since 2015, Japan has restarted 13 reactors with a total capacity of 12.4 GW, which has reduced the country’s liquefied natural gas (LNG) imports by more than 20% (from 115.9 billion cubic meters in 2015 to 90.3 billion cubic meters in 2023, according to the Energy Institute).
A similar situation is observed in the United States. According to the road map released by the U.S. Government in November, titled Safely and Responsibly Expanding U.S. Nuclear Energy: Deployment Targets and a Framework for Action, the United States has one of the oldest and most worn-out NPP fleets in the world. Most of U.S.-based NPPs were built in the 1970s and 1980s. Over the past 10 years, only the third and fourth power units with Gen III+ AP1000 reactors have been launched at the Vogtle NPP in Georgia, and even that was achieved with a seven-year delay. As a result, the share of NPPs in the U.S. energy mix is currently below 7.5%, behind solar, wind, gas- and coal-fired power generation.
In order to somehow revive the nuclear industry, the U.S. Government has proposed extending licenses for the operation of NPPs to 80–100 years and restarting old reactors that were decommissioned for economic reasons.
This has allowed the IT giant Microsoft to sign a 20-year contract for the modernization and purchase of electricity from the second power unit of the notorious Three Mile Island NPP. Its first unit was shut down in 1979 due to the largest accident in the history of nuclear power, and the second one was closed in 2019 due to low profitability. The reason for increased demand is the need to supply data centers with clean energy around the clock: only NPPs meet this requirement.
A similar problem exists in Russia. In late November 2024, Russia’s Deputy Energy Minister Yevgeny Grabchak said that Russia will need to decommission 26 power units of old NPPs in the next 70 years. “Today, the total number is 35 power units. Of these, nine have already been decommissioned. Overall, we will need RUB 3 trillion to achieve this goal by 2093,” he said. The Energy Ministry has already established a commission to analyze the operating NPPs and their service life.
In general, technological obsolescence will become an increasingly acute problem for the nuclear power industry. According to the IAEA, there were 416 power units operating worldwide by December 2024 with an aggregate net capacity of 374.5 GW, of which 161 reactors totaling 150.3 GW were operating at NPPs with a service life of 37 to 44 years. It should be noted that it is even more complex and expensive to decommission NPPs, mothball power units and destroy concrete structures at NPPs than to upgrade reactors or build new ones. This is why there is already an urgent need in the industry to develop technologies that extend the life of NPPs.
“NPPs are complex facilities. As a rule, the designs of nuclear reactors that were built in the 1970s and 1980s envisaged large margins of safety, as the experience of operating nuclear reactors and auxiliary equipment was negligible. This makes it possible to reliably extend their service life beyond the 30 years embedded in the design. Currently, extending the service life of NPPs is a global practice. This process is strictly regulated and supervised by regulatory authorities,” professor Georgy Tikhomirov, Deputy Director of the Institute of Nuclear Physics and Engineering of NRNU MEPhI, doctor of physical and mathematical sciences, told Global Energy.
“This is why I believe that all nuclear reactors operating today are equally reliable and safe, regardless of their service life. It should be said that modern nuclear power plants are designed for a service life of 60 years or more, since, according to the IAEA, the operating experience of nuclear power reactors has already exceeded 20,000 reactor-years,” he noted.
At the same time, extending the service life of NPPs does not mean industry stagnation and suspension of new construction projects. “Big nuclear construction has been underway for the last twenty years. The fleet of operating reactors is constantly being updated. Every year, five to seven nuclear reactors stop generating energy and enter the decommissioning process, and roughly the same number of new nuclear reactors begin their operation. As of December 2024, the IAEA Database listed 63 power units under construction, with the total number of operating power units at 416,” the expert said.