Nuclear Waste: Opportunities Exist to Reduce Risks and Costs by Evaluating Different Waste Treatment Approaches at Hanford, Report to Congressional Addressees [open pdf - 5MB]
"DOE [Department of Energy] oversees the treatment and disposal of about 90 million gallons of radioactive waste from the nation's nuclear weapons program. Most of this waste is stored in tanks at DOE sites in Hanford, Washington, and Savannah River, South Carolina. The less radioactive portion of the tank waste, called LAW [low-activity waste], comprises more than 90 percent of the waste's volume but less than 10 percent of the total radioactivity. DOE has chosen different approaches for treating LAW at the two sites, but it has not made a final decision on how to treat Hanford's supplemental LAW. GAO [Government Accountability Office] examined (1) DOE's reasons for choosing its treatment approaches for LAW at the Savannah River and Hanford Sites, (2) the status of DOE's treatment of LAW at these sites, and (3) experts' views on the likely performance of approaches for treating Hanford's LAW. GAO reviewed technical reports on DOE's waste treatment strategies at the two sites, interviewed DOE officials at headquarters and the sites, and convened an experts' meeting through the National Academies to discuss the effectiveness and risks of vitrification and grout. […] Congress should consider specifically authorizing DOE to classify Hanford's supplemental LAW based on risk, consistent with existing regulatory authorities. GAO also recommends that DOE develop updated information on the performance of treating LAW with alternate methods, such as grout, before it selects an approach for treating supplemental LAW. DOE agreed with both recommendations."
Government Accountability Office: http://www.gao.gov/