 In the U.S. there are 13 reactors that have permanently shut down and are in some phase of decommissioning, but none of them have completed the process.New methods for decommissioning have been developed in order to minimize the usual high decommissioning costs.One of these methods is in situ decommissioning (ISD), which was implemented at the U.S. Department of Energy Savannah River Site in South Carolina for the closures of the P and R Reactors.