Two diversion boxes were covered with concrete to permanently close them from future use. Top, one of the boxes is shown prior to it being entombed in concrete. Bottom, the diversion box after workers placed concrete over and around the structure. (Photo: DOE)

Two previously radioactive structures have been successfully entombed at the Department of Energy’s Savannah River Site in South Carolina. The DOE’s Office of Environmental Management and the Savannah River Mission Completion (SRMC), the DOE’s liquid waste contractor at SRS, placed concrete over and around two concrete structures—called diversion boxes—that contain a series of connection points that allowed high-level radioactive waste to be transferred from one tank or facility to another.

The two boxes have been out of service for more than 30 years. As part of the closure process, both structures were previously filled with grout, rendering them inoperable.

The boxes were the first ancillary structures closed in this way under SRMC’s liquid waste contract. They are located in the F Tank Farm, a grouping of large underground waste-storage tanks. The liquid waste program at SRS has closed eight of the site’s 51 massive waste tanks by filling them with cementitious grout.