Radioactive wastes resulting from over 40 years of production of nuclear weapons in the U. S. are currently stored in 273 underground tanks at the U. S. Department of Energy Hanford site, Idaho National Engineering and Environmental Laboratory, Oak Ridge Reservation, and Savannah River site. Combined, tanks at these sjtes contain approximately 94,000,000 gallons of waste in a variety of forms including liquid, concrete-like salt cake, and various sludges. More than 730,000,000 curies of several radioactive isotopes are present in the underground tanks. Certainly, one of the greatest challenges facing the U. S. Department of Energy is how to characterize, retrieve, treat, and immobilize the great variety of tank wastes in a safe, timely, and cost-effective manner. For several years now, the U. S. Department of Energy has initiated and sponsored scientific and engineering studies, tests, and demonstrations to develop the myriad of technologies required to dispose of the radioactive tank wastes. In recent times, much of the Department of Energy R&D activities concerning tank wastes have been closely coordinated and organized through the Tanks Focus Area (IF A); responsibility for technical operations of the TF A has been assigned to the Pacific Northwest National Laboratory.

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.

Advanced separations technology is key to closing the nuclear fuel cycle and relieving future generations from the burden of radioactive waste produced by the nuclear power industry. Nuclear fuel reprocessing techniques not only allow for recycling of useful fuel components for further power generation, but by also separating out the actinides, lanthanides and other fission products produced by the nuclear reaction, the residual radioactive waste can be minimised. Indeed, the future of the industry relies on the advancement of separation and transmutation technology to ensure environmental protection, criticality-safety and non-proliferation (i.e., security) of radioactive materials by reducing their long-term radiological hazard.Advanced separation techniques for nuclear fuel reprocessing and radioactive waste treatment provides a comprehensive and timely reference on nuclear fuel reprocessing and radioactive waste treatment. Part one covers the fundamental chemistry, engineering and safety of radioactive materials separations processes in the nuclear fuel cycle, including coverage of advanced aqueous separations engineering, as well as on-line monitoring for process control and safeguards technology. Part two critically reviews the development and application of separation and extraction processes for nuclear fuel reprocessing and radioactive waste treatment. The section includes discussions of advanced PUREX processes, the UREX+ concept, fission product separations, and combined systems for simultaneous radionuclide extraction. Part three details emerging and innovative treatment techniques, initially reviewing pyrochemical processes and engineering, highly selective compounds for solvent extraction, and developments in partitioning and transmutation processes that aim to close the nuclear fuel cycle. The book concludes with other advanced techniques such as solid phase extraction, supercritical fluid and ionic liquid extraction, and biological treatment processes.With its distinguished international team of contributors, Advanced separation techniques for nuclear fuel reprocessing and radioactive waste treatment is a standard reference for all nuclear waste management and nuclear safety professionals, radiochemists, academics and researchers in this field. - A comprehensive and timely reference on nuclear fuel reprocessing and radioactive waste treatment - Details emerging and innovative treatment techniques, reviewing pyrochemical processes and engineering, as well as highly selective compounds for solvent extraction - Discusses the development and application of separation and extraction processes for nuclear fuel reprocessing and radioactive waste treatment

The Department of Energy's Office of Environmental Management (DOE-EM) is responsible for cleaning up radioactive waste and environmental contamination resulting from five decades of nuclear weapons production and testing. A major focus of this program involves the retrieval, processing, and immobilization of waste into stable, solid waste forms for disposal. Waste Forms Technology and Performance, a report requested by DOE-EM, examines requirements for waste form technology and performance in the cleanup program. The report provides information to DOE-EM to support improvements in methods for processing waste and selecting and fabricating waste forms. Waste Forms Technology and Performance places particular emphasis on processing technologies for high-level radioactive waste, DOE's most expensive and arguably most difficult cleanup challenge. The report's key messages are presented in ten findings and one recommendation.

This volume opens with a keynote lecture by Rodney Ewing, member of the Board of Radioactive Waste Management of the National Research Council. Ewing summarizes 25 years of materials research in nuclear waste, emphasizing the progress that has been made and the challenges that still confront investigators and technologists in materials science and repository performance evaluation. The session is followed by one on container materials and engineered barriers, and includes a discussion on the corrosion performance expected for waste packages in the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. Invited papers on performance assessment and repository studies for different national programs are also highlighted, with representation from the United States, Sweden, Japan, Belgium, Switzerland, Italy, and the United Kingdom. A large number of papers focus on the structure, properties, and degradation of various waste forms such as glasses, ceramics (mostly for plutonium immobilization), cements, and spent nuclear fuel. For the second consecutive time, the number of papers on ceramics far exceeds those on glass, which had been the dominant material discussed at this symposium over the prior 23 years. New studies on zirconates confirm the recently discovered high radiation damage-resistance of this material. Additional topics include: performance assessment in high-level waste disposal; performance assessment in low-level waste disposal; ceramic structure and corrosion; radiation effects in ceramics; glass structure and corrosion; spent fuel; spent fuel cladding and alternative waste forms; cements in radioactive waste immobilization; contaminant transport; natural analogs; and waste processing.

The Department of Energy's Office of Environmental Management (DOE) is responsible for the safe cleanup of sites used for nuclear weapons development and government-sponsored nuclear energy research. Low-level radioactive waste (LLW) is the most volumetrically significant waste stream generated by the DOE cleanup program. LLW is also generated through commercial activities such as nuclear power plant operations and medical treatments. The laws and regulations related to the disposal of LLW in the United States have evolved over time and across agencies and states, resulting in a complex regulatory structure. DOE asked the National Academies of Sciences, Engineering, and Medicine to organize a workshop to discuss approaches for the management and disposition of LLW. Participants explored the key physical, chemical, and radiological characteristics of low-level waste that govern its safe and secure management and disposal in aggregate and in individual waste streams, and how key characteristics of low level waste are incorporated into standards, orders, and regulations that govern the management and disposal of LLW in the United States and in other major waste-producing countries. This publication summarizes the presentations and discussions from the workshop.

Engineering Separations Unit Operations for Nuclear Processing provides insight into the fundamentals of separations in nuclear materials processing not covered in typical texts. This book integrates fuel cycle and waste processing into a single, coherent approach, demonstrating that the principles from one field can and should be applied to the other. It provides historical perspectives on nuclear materials processing, current assessment and challenges, and how past challenges were overcome. It also provides understanding of the engineering principles associated with handling nuclear materials. This book is aimed at researchers, graduate students, and professionals in the fields of chemical engineering, mechanical engineering, nuclear engineering, and materials engineering.