The Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) (Ecology et al. 1994), requires the retrieval of 99 percent of the Hanford Site single-shell tank (SST) waste. Retrieval of the waste requires the completion of saltwell pumping and then the sluicing of all 149 tanks, at a cost of over $3 billion. The retrieved waste is to be processed and vitrified for ultimate disposal as glass. This document shows that the intent of the Tri-Party Agreement can be met by sluicing the waste from only 86 tanks, after the completion of saltwell pumping. This partial retrieval option will result in a cost savings of over $600 million in construction and operation alone, and will significantly reduce the volume of glass requiring disposal.

DOE Tank Waste: How clean is clean enough? The U.S. Congress asked the National Academies to evaluate the Department of Energy's (DOE's) plans for cleaning up defense-related radioactive wastes stored in underground tanks at three sites: the Hanford Site in Washington State, the Savannah River Site in South Carolina, and the Idaho National Laboratory. DOE plans to remove the waste from the tanks, separate out high-level radioactive waste to be shipped to an off-site geological repository, and dispose of the remaining lower-activity waste onsite. The report concludes that DOE's overall plan is workable, but some important challenges must be overcomeâ€"including the removal of residual waste from some tanks, especially at Hanford and Savannah River. The report recommends that DOE pursue a more risk-informed, consistent, participatory, and transparent for making decisions about how much waste to retrieve from tanks and how much to dispose of onsite. The report offers several other detailed recommendations to improve the technical soundness of DOE's tank cleanup plans.