U.S. has successfuly decommissioned 10 nuclear plants

As of 2017, 10 U.S. nuclear power plants have been successfully decommissioned, and another 20 U.S. nuclear reactors are currently in different stages of the decommissioning process, says the Energy Information Administration.

Since 2013, six commercial nuclear reactors in the U.S. have been shut down and an additional eight reactors have announced plans to retire by 2025, Kallanish Energy has learned..

The retirement process for nuclear power plants involves disposing of nuclear waste and decontaminating equipment and facilities to reduce residual radioactivity, thus making it more expensive and time-consuming that retiring other power plants, the federal agency said.

There are three methods to decommission a nuclear reactor: to decontaminate by removing all fuel and equipment from the plant; safe storage where the site is dismantled and then monitored for up to 50 years until radiation drops to safe levels; and entombing the entire site in concrete, a method not used in the U.S. but used in other countries, EIA reported.

One of the most recently decommissioned U.S. nuclear reactors is the 619-megawatt Haddam Neck plant in central Connecticut. It was shut down in 1997 and decommissioned using the decontamination process. The decommissioning was completed in 2007, at a cost of $893 million.

More recently, the 556 MW Kewaunee Nuclear Power Plant in eastern Wisconsin was shut down in 2013. Dominion Power anticipates nearly $1 billion in total costs using the safe storage option. It says the work won’t be done until 2073.

The EIA said the decommissioning process is considered complete when the Nuclear Regulatory Commission determines the decommissioning complies with the plans submitted to the agency by the operator at the beginning of the process. A final radiation survey is also conducted.

The decommissioning is paid for through a fund that each plant operator creates during construction.

According to the World Nuclear Association, about two thirds of the total estimated cost of decommissioning all U.S. nuclear reactors has already been collected.

When reactors are retired earlier than planned, a shortfall in funding may result in additional expenses to electric ratepayers, the EIA said.