The management of low-level radioactive wastes at Oak Ridge National Laboratory (ORNL) is complicated because of several factors: (1) some of the waste that had been disposed previously does not meet current acceptance criteria; (2) waste is presently being generated both because of ongoing operations as well as the remediation of former disposal sites; and (3) low-level radioactive waste streams that also contain chemically toxic species (mixed wastes) are involved. As a consequence, the waste management activities at ORNL range from the application of standard practices to the development of new technologies to address the various waste management problems. Considerable quantities of low-level radioactive wastes had been disposed in trenches at the ORNL site, and the trenches subsequently covered with landfill. Because the vadose zone is not very extensive in the waste burial area, many of these trenches were located partially or totally within the saturated zone. As a result, considerable amounts of radioactive cesium have been leached from the wastes and have entered the groundwater system. Efforts are currently underway to remediate the problem by excluding groundwater transport through the burial site. A number of waste streams have also been generated that not only contain low levels of radioactive species, but chemically noxious species as well. These mixed wastes'' are currently subject to storage and disposal restrictions imposed on both low-level radioactive materials and on substances subject to the Resource Conservation and Recovery Act (RCRA). Technologies currently under development at ORNL to treat these mixed wastes are directed toward separating the RCRA components from the radioactive species, either through destruction of the organic component using chemical or biochemical processes, or the application of solvent extraction or precipitation techniques to effect separation into dependent waste forms. 8 refs., 3 figs.

Management of radioactive waste at Oak Ridge National Laboratory (ORNL) must address several major challenges. First, contaminants from some disposed wastes are leaching into the groundwater and these disposal sites must be remediated. Second, some of these ''legacy'' wastes, as well as currently generated radioactive wastes, are also contaminated with chemicals, including polychlorinated biphenyls (PCBs), solvents, and metals (i.e., mixed waste). Third, wastes containing long-lived radionuclides in concentrations above established limits have been determined unsuited for disposal on the Oak Ridge Reservation. Reflecting these challenges, ORNL's strategy for managing its radioactive wastes continues to evolve with the development of improved technologies and site-specific adaptation of some standard technologies.

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.

The Atomic Energy Act of 1954 vested in the Atomic Energy Commission the exclusive authority to regulate source, special nuclear, and byproduct materials and to own and operate the facilities for their production. It further authorized the Commission to regulate any activity covered by the Act in order to protect health and to minimize danger to life and property. In addition, Executive Order 12088 of October 13, 1978, required federal agencies to meet pollution control standards equivalent to those required of the regulated community. These legislative mandates had been interpreted to exempt federal Atomic Energy Act facilities from all outside regulation, until the recent, successful, legal challenge to this interpretation. This court challenge raised the prospect of dual regulation of mixed (radioactive and chemically hazardous) wastes and led us to analyze the consequences of such dual regulation. In addition, the Environmental Protection Agency and the Department of Energy have been developing a basis for delineating their relative responsibilities in order to avoid the necessity for a dual program. 1 reference, 1 table.

A literature survey was conducted to help determine the feasibility of solidifying a liquid low-level radioactive mixed waste in the inactive tank system at Oak Ridge National Laboratory (ORNL). The goal of this report is to facilitate a decision on the disposition of these wastes by identifying any waste constituents that might (1) compromise the strength or stability of the waste form or (2) be highly leachable. Furthermore, its goal is to identify ways to circumvent interferences and to decrease the leachability of the waste constituents. This study has sought to provide an understanding of inhibition of cement set by identifying the fundamental chemical mechanisms by which this inhibition takes place. From this fundamental information, it is possible to draw some conclusions about the potential effects of waste constituents, even in the absence of particular studies on specific compounds.

A literature survey was conducted to help determine the feasibility of solidifying a liquid low-level radioactive mixed waste in the inactive tank system at Oak Ridge National Laboratory (ORNL). The goal of this report is to facilitate a decision on the disposition of these wastes by identifying any waste constituents that might (1) compromise the strength or stability of the waste form or (2) be highly leachable. Furthermore, its goal is to identify ways to circumvent interferences and to decrease the leachability of the waste constituents. This study has sought to provide an understanding of inhibition of cement set by identifying the fundamental chemical mechanisms by which this inhibition takes place. From this fundamental information, it is possible to draw some conclusions about the potential effects of waste constituents, even in the absence of particular studies on specific compounds.