[en] Radionuclides such as ⁹⁹Tc are by-products of fission reactions in high-level wastes. Technetium poses a serious environmental threat because it is easily oxidized into its highly leachable pertechnetate form. Magnesium potassium phosphate ceramics have been developed to treat ⁹⁹Tc that has been separated and eluted from simulated high-level tank wastes by sorption processes. Dense and hard ceramic waste forms were fabricated by acid-base reactions between mixtures of magnesium oxide powders and wastes, and acid phosphate solutions. Standard leaching tests, such as ANS 16.1 and the Product Consistency Test, were conducted on the final waste forms to establish their performance. The fate of the contaminants in the final waste forms was established with scanning electron microscopy techniques. In addition, stability of the waste forms in aqueous environments was evaluated by long-term water immersion tests

[en] The Final Waste Management Programmatic Environmental Impact Statement (WM PEIS) examines the potential environmental and cost impacts of strategic management alternatives for managing five types of radioactive and hazardous wastes that have resulted and will continue to result from nuclear energy research and the development, production, and testing of nuclear weapons at a variety of sites around the United States. The five waste types are low-level mixed waste, low-level waste, transuranic waste, high-level waste, and hazardous waste. The WM PEIS provides information on the impacts of various siting alternatives, which the Department of Energy (DOE) will use to decide at which sites to locate additional treatment, storage, and disposal capacity for each waste type. This information includes the cumulative impacts of combining future siting configurations for the five waste types and the collective impacts of other past, present, and reasonably foreseeable future activities. The selected waste management facilities being considered for these different waste types are treatment and disposal facilities for low-level mixed waste; treatment and disposal facilities for low-level waste; treatment and storage facilities for transuranic waste in the event that treatment is required before disposal; storage facilities for created (vitrified) high-level waste canisters; and treatment of nonwastewater hazardous waste by DOE and commercial vendors. In addition to the No Action Alternative, which includes only existing of approved waste management facilities, the alternatives for each of the waste-type configurations include Decentralized, Regionalized, and Centralized Alternatives for using existing and operating new waste management facilities. However, the siting, construction, and operations of any new facility at a selected site will not be decided until completion of a sitewide or project-specific environmental impact review

[en] The Belgian Nuclear Research Centre SCK-CEN has patented a new process for the treatment of metallic sodium. This process is fully integrated since it allows to vitrify easily the mixture resulting from the oxidation step. To ensure the link between the treatment and the conditioning, the vitrification conditions have been studied. It is confirmed that an adequate control of the temperature decrease during the vitrification is essential to obtain a product whose area is well known and controlled. Also, the release of Cs and Co has been examined through leaching tests. The study has led to the choice of adequate composition ranges for SiO₂, Na₂O, Al₂O₃, B₂O₃ and CaO. Further studies will be carried out to assess the possible use of vitro-crystalline materials for long term conditioning. vitro-crystalline materials for long term conditioning

[en] The current research project on partitioning and transmutation at the Dept. of Nuclear Chemistry, CTH, has the primary objective to investigate separation processes useful in connection with transmutation of long-lived radionuclides in high level nuclear waste. Partitioning is necessary in order to recover and purify the elements before and after each irradiation in a P and T treatment. In order to achieve a high transmutation efficiency the chemical separation process used must have small losses to various waste streams. At present, only aqueous based separation processes are known to be able to achieve the high recovery and separation efficiencies necessary for a useful P and T process

[en] The Integrated Radwaste Treatment System (IRTS) at the West Valley Demonstration Project (WVDP) is a pretreatment scheme to reduce the amount of salts in the high-level radioactive waste (vitrification) stream. Following removal of cesium-137 (Cs-137) by ion-exchange in the Supernatant Treatment System (STS), the radioactive waste liquid is volume-reduced by evaporation. Trace amounts of Cs-137 in the resulting distillate are removed by ion-exchange, then the distillate is discharged to the existing plant water treatment system. The concentrated product, 37 to 41 percent solids by weight, is encapsulated in cement producing a stable, low-level waste form. The Integrated Radwaste Treatment System (IRTS) operated in this mode from May 1988 through November 1990, decontaminating 450,000 gallons of high-level waste liquid; evaporating and encapsulating the resulting concentrates into 10,393 71-gallon square drums. A number of process changes and variations from the original operating plan were required to increase the system flow rate and minimize waste volumes. This report provides a summary of work performed to operate the IRTS, including system descriptions, process highlights, and lessons learned

[en] As part of the technical support CST-12 provides for a wide variety of defense and nondefense programs within Los Alamos National Laboratory (LANL) and the Department of Energy (DOE) complex, new waste minimization technique is under development for radiological volatile organic analysis (Hot VOA). Currently all HOT VOA must be run in a glovebox. Several types of sample contain TRU radiological waste in the form of particulates. By prefiltering the samples through a 1.2 micron syringe and counting the radioactivity, it has been found that many of the samples can be analyzed outside a glovebox. In the present investigation, the types of Hot VOA samples that can take advantage of this new technique, the volume and types of waste reduced and the experimental parameters will be discussed. Overall, the radioactive waste generated is minimized

[en] The Office of Environmental Management (EM) has been delegated the responsibility for the Department of Energy's (DOE's) cleanup of the nuclear weapons complex. The nature and magnitude of the waste management and environmental remediation problem requires the identification of technologies and scientific expertise from domestic and foreign sources. Within the United States, operational DOE facilities, as well as the decontamination and decommissioning of inactive facilities, have produced significant amounts of radioactive, hazardous, and mixed wastes. In order to ensure worker safety and the protection of the public, DOE must: (1) assess, remediate, and monitor sites and facilities; (2) store, treat, and dispose of wastes from past and current operations; and (3) develop and implement innovative technologies for environmental restoration and waste management. The EM directive necessitates looking beyond domestic capabilities to technological solutions found outside US borders. Following the collapse of the Soviet regime, formerly restricted elite Soviet scientific expertise became available to the West. EM has established a cooperative technology development program with Russian scientific institutes that meets domestic cleanup objectives by: (1) identifying and accessing Russian EM-related technologies, thereby leveraging investments and providing cost-savings; (2) improving access to technical information, scientific expertise, and technologies applicable to EM needs; and (3) increasing US private sector opportunities in Russian in EM-related areas

No abstract available

No abstract available

No abstract available