As eight nuclear reactors prepare for retirement within the coming decade, the Energy Information Administration (EIA) reports that decommissioning just one nuclear power plant can cost up to $1 billion or take nearly 60 years to complete. Since 2013, six commercial nuclear reactors in the United States have shut down and begun the process.        

As of 2017, a total of 10 commercial nuclear reactors in the U.S. have been successfully decommissioned, and another 20 are currently in different stages of the decommissioning process.

Retirement involves disposing of nuclear waste, decontaminating equipment and providing ways to reduce residual radioactivity, making it much more expensive and time consuming than retiring other power plants. Full decommission means the facility must be deconstructed and the site returned to greenfield status – suitable for purposes such as housing, farming, or industrial use. In the U.S., nuclear plants are decommissioned using two strategies:

  • Decontamination (DECON) is the relatively faster method of decommissioning a nuclear reactor and involves removing all fuel and equipment from the power plant. The fuel and equipment represent the bulk of the irradiated material on the site and are removed for separate storage and decontamination. DECON can take at least seven years and allows for the relatively quick return of the land for reuse.
  • Safe Storage (SAFSTOR), also known as deferred dismantling, involves containing and monitoring the reactor and equipment until radiation drops to safe levels. The SAFSTOR timeline allows for up to 50 years of containment followed by up to 10 years for decontamination. The longer timeline of the SAFSTOR method can allow some radioactive contamination to decay to safe levels, reducing the amount of radioactive material that must be disposed of, which can reduce the total decommissioning cost. Operators also have more time to secure funds to pay for the decommissioning process over the longer timeframe of the SAFSTOR process.

nuclear decommissionA third technique, known as ENTOMB, involves permanently entombing the entire site in concrete. This method is not used for commercial reactors in the United States, but it has been used in other countries. For example, the Chernobyl 4 reactor in Ukraine has been entombed in a steel shelter designed to prevent radiation leaks from the site.

One of the most recently decommissioned reactors in the United States is the 619-megawatt Haddam Neck plant in central Connecticut, which was shut down in 1997 and decommissioned using the DECON method. Haddam Neck’s decommissioning was completed in 2007 at a total cost of $893 million.

More recently, the 556-megawatt Kewaunee Nuclear Power Plant in eastern Wisconsin was shut down in 2013. Kewaunee’s operator, Dominion Power, anticipates nearly $1 billion in total costs using the SAFSTOR method and estimates that work will not be complete until 2073.