ABSTRACT
Once it has been decided to finally shut down an operating facility, whether it be a small R&D laboratory building or a power reactor station, the planning for decommissioning begins in earnest. Deciding not to decommission a facility once it has been shut down is usually not an option, definitely the case for nuclear reactors. So one of the first considerations is to select the most appropriate decommissioning alternative: DECON, SAFSTOR or ENTOMB. While these designations are typically used for decommissioning nuclear reactors; nearly all materials licensees select the DECON option. In the next two sections these decommissioning options will be defined and their attributes presented. The remainder of this chapter focuses specifically on the DECON option, and the final status surveys and verification process that are used in conjunction with DECON.
DECON is the most popular option because it settles the site decommissioning concerns once and for all. It includes complete facility decommissioning and license termination (or similar shutdown status) immediately following final shutdown. Specifically, the facility is decontaminated and/or dismantled to levels that permit release; contaminated equipment is either decontaminated or removed as radioactive waste. In the case of shut down nuclear power reactors, the reactor is defueled-i.e. the spent fuel is placed in the spent fuel pool. This is the predominant source of risk that exists at shut down reactors during decommissioning. Many times the fuel is transferred from the spent fuel pool to a more stable configuration-the on-site independent spent fuel storage installation or ISFSI. Spent fuel is expected to be stored in dry casks in on-site ISFSIs until a long-term solution is implemented for high-level radioactive waste. Currently, the Department of Energy is investigating the feasibility of constructing a high-level radioactive waste disposal site in Yucca Mountain, Nevada.
