Research Opportunities For Managing The Department Of Energy S Transuranic And Mixed Wastes

About 155,000 cubic meters of waste contaminated with both radioactive isotopes and hazardous chemicals are stored at some 30 DOE sites, and another 450,000 cubic meters are buried. While DOE is making a concerted effort to properly dispose of this waste, the amount translates to a multi-decade effort that will require handling, characterizing, and shipping hundreds of thousands of waste containers at a total cost of billions of dollars. This report describes basic scientific research that can lead to new technologies for performing these tasks more safely and cost effectively.

The Department of Energy's Office of Environmental Management (EM) directs the massive cleanup of more than 100 sites that were involved in the production of nuclear weapons materials during the Manhattan Project and the Cold War. This report offers suggestions for more effectively characterizing and treating the orphan and special-case wastes that are part of EM's accelerated cleanup program. It identifies technical opportunities for EM to improve the program that will save time and money without compromising health and safety. The opportunities identified include: making more effective use of existing facilities and capabilities for waste characterization, treatment, or disposal; eliminating self-imposed requirements that have no clear technical or safety basis; and investing in new technologies to improve existing treatment and characterization capabilities. For example, the report suggests that EM work with DOE classification officers to declassify, to the extent possible, classified materials declared as wastes. The report also suggests a new approach for treating the wastes that EM will leave in place after cleanup.

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.

The production of nuclear materials for the national defense was an intense, nationwide effort that began with the Manhattan Project and continued throughout the Cold War. Now many of these product materials, by-products, and precursors, such as irradiated nuclear fuels and targets, have been declared as excess by the Department of Energy (DOE). Most of this excess inventory has been, or will be, turned over to DOE's Office of Environmental Management (EM), which is responsible for cleaning up the former production sites. Recognizing the scientific and technical challenges facing EM, Congress in 1995 established the EM Science Program (EMSP) to develop and fund directed, long-term research that could substantially enhance the knowledge base available for new cleanup technologies and decision making. The EMSP has previously asked the National Academies' National Research Council for advice for developing research agendas in subsurface contamination, facility deactivation and decommissioning, high-level waste, and mixed and transuranic waste. For this study the committee was tasked to provide recommendations for a research agenda to improve the scientific basis for DOE's management of its high-cost, high-volume, or high-risk excess nuclear materials and spent nuclear fuels. To address its task, the committee focused its attention on DOE's excess plutonium-239, spent nuclear fuels, cesium-137 and strontium-90 capsules, depleted uranium, and higher actinide isotopes.