Download or read book Technetium Inventory Distribution and Speciation in Hanford Tanks written by and published by . This book was released on 2014 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this report is three fold: 1) assemble the available information regarding Tc inventory, distribution between phases, and speciation in Hanford's 177 storage tanks into a single, detailed, comprehensive assessment; 2) discuss the fate (distribution/speciation) of Tc once retrieved from the storage tanks and processed into final waste forms; and 3) discuss/document in less detail the available data on the inventory of Tc in other "pools" such as the vadose zone below inactive cribs and trenches, below single-shell tanks (SSTs) that have leaked, and in the groundwater below the Hanford Site. This report was revised in September 2014 to add detail and correct inaccuracies in Section 5.0 on the fate of technetium (Tc) recycle from the off-gas systems downstream of the low-activity waste (LAW) melters back to the melters, based on several reports that were not found in the original literature search on the topic. The newly provided reports, from experts active in the Hanford Tank Waste Treatment and Immobilization Plant (WTP) glass studies, the Vitreous State Laboratory at The Catholic University of America (VSL) melter and off-gas system demonstrations and overall WTP systems analysis, were not originally found on electronic databases commonly searched. The major revisions to Section 5.0 also required changes to Section 7.0 (Summary and Conclusions) and this executive summary.
Download or read book Technitium Management at the Hanford Site written by and published by . This book was released on 2013 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: Long Abstract. Full Text. The Hanford tank waste contains approx 26,000 Ci of technetium-99 (Tc-99), the majority of which is in the supernate fraction. Tc-99 is a long-lived radionuclide with a half-life of approx 212,000 years and, in its predominant pertechnetate (TcO4) form, is highly soluble and very mobile in the vadose zone and ultimately the groundwater. Tc-99 is identified as the major dose contributor (in groundwater) by past Hanford site performance assessments and therefore considered a key radionuclide of concern at Hanford. The United States Department of Energy (DOE) River Protection Project's (RPP) long-term Tc-99 management strategy is to immobilize the Tc-99 in a waste form that will retain the Tc-99 for many thousands of years. To achieve this, the RPP flowsheet will immobilize the majority of the Tc-99 as a vitrified low-activity waste product that will be ultimately disposed on site in the Integrated Disposal Facility. The Tc-99 will be released gradually from the glass at very low rates such that the groundwater concentrations at any point in time would be substantially below regulatory limits. The liquid secondary waste will be immobilized in a low-temperature matrix (cast stone) and the solid secondary waste will be stabilized using grout. Although the Tc-99 that is immobilized in glass will meet the release rate for disposal in IDF, a proportion is driven into the secondary waste stream that will not be vitrified and therefore presents a disposal risk. If a portion of the Tc-99 were to be removed from the Hanford waste inventory and disposed off-site, (e.g., as HLW), it could lessen a major constraint on LAW waste form performance, i.e., the requirement to retain Tc-99 over thousands of years and have a positive impact on the IDF Performance Assessment. There are several technologies available at various stages of technical maturity that can be employed for Tc-99 removal. The choice of technology and the associated efficacy of the technology are dependent on the chemical fonn of the technetium in the waste, the removal location in the tlowsheet. and the ultimate disposition path chosen for the technetium product. This paper will discuss the current plans for the management of the technetium present in the Hanford tank waste. It will present the risks associated with processing technetium in the current treatment flowsheet and present potential mitigation opportunities, the status of available technetium removal technologies, the chemical speciation of technetium in the tank waste, and the available disposition paths and waste forms for technetium containing streams.
Download or read book Development of a Chemistry based Predictive Method for Determining the Amount of Non pertechnetate Technetium in the Hanford Tanks written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy and Water Development Appropriations for 2017 Department of Energy Secretary of Energy written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2016 with total page 1060 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy and Water Development Appropriations for 2018 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2017 with total page 1360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Determination of Pertechnetate and Non Pertechnetate Species in Hanford Tanks Phase 1 written by and published by . This book was released on 2014 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytical method is required to distinguish between the pertechnetate and non-pertechnetate forms of technetium; currently, the methods available only report the total technetium present in a sample. The overall objective of this effort is to develop a method for routinely analyzing Hanford tank waste for technetium in the pertechnetate and the non-pertechnetate forms. A phased approach will be deployed to accomplish this objective: Phase I Comparison of existing technetium analysis methods with modification; Phase II Demonstration of modified methods using non-pertechnetate spiked simulants; and, Phase III Demonstration of chosen method on Hanford tank sample containing non-pertechnetate. This report describes the Phase I work, providing a comparison of Aliquat 336 and TEVA(R)1 in the removal of pertechnetate and discussing the subsequent analysis for technetium in both alkaline and acidic environments without oxidation. The effort was executed under LAB-PLN-13-00004, The Determination of Pertechnetate and Non-Pertechnetate Species in Hanford Tanks Phase I.
Download or read book The chemical speciation of technetium in the environment written by S. T. Sparkes and published by . This book was released on 1987 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book APS Science written by Advanced Photon Source (Research facility) and published by . This book was released on 2004 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamental Chemistry Characterization and Separation of Technetium Complexes in Hanford Waste written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ultimate goal of this project is to separate technetium from Hanford tank waste. Our prior work with Hanford waste has shown that a large portion of the technetium in some tanks is not pertechnetate (TcOd) and is not easily oxidized to it. This has serious repercussions for technetium partitioning schemes because they are designed to separate this chemical form. Rational attempts to oxidize these species to Tc04* for processing or to separate the non-pertechnetate species themselves would be facilitated by knowing the identity of these 5 complexes and understanding their fundamental chemistry. Tank characterization work has not yet identified any of the non-pertechnetate species. However, based on the types of ligands available and the redox conditions in the tank, a reasonable speculation can be made about the types of species that may be present. 3 Thus, this project was synthesizing relevant model complexes of Tc(III), Tc(IV), and Tc(V) that may form under tank waste conditions. The complexes were to be characterized and used as standards for characterizing the nonpertechnetate species in actual waste using instrumental techniques such as XAS and subsequent EXAFS and XANES analysis. We had hoped to study the redox chemistry of the technetium complexes so that more efficient and selective oxidative methods can be used to bring the tank non-pertechnetate species to TcOd for processing purposes. We were to study the ligand substitution chemistry of the synthesized complexes, which could be used to develop separation methods for non-pertechnetate species. Understanding the fundamental chemistry of these technetium complexes hopefully will enable technetium to be efficiently removed from the Hanford tank waste and help DOE to fulfill its remediation mission.
Download or read book Technetium Attenuation in the Vadose Zone written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-level waste (HLW) has leaked into the vadose zone from buried single-shell tanks at the Hanford Site. Contaminant plumes containing radionuclides are slowly migrating toward the groundwater table. The accepted model of contaminant migration places technetium (Tc) at the leading edge of the plume due to the high mobility of the anionic species, TcO4−, in its oxidized state. However, recent drilling and sampling programs at the B-BX-BY and S-SX Hanford Site tank farms have revealed that the Tc distribution within the contaminant plume is more complex than anticipated and some Tc may be retained in the vadose zone as insoluble precipitates. This research project investigates possible mechanisms by which Tc associated with HLW leakages can be attenuated in the vadose zone. It also will provide fundamental information on surface mediated reduction/precipitation reactions of Tc on Fe{sup II}-containing mineral surfaces and the stability of Tc precipitates under conditions in the va dose zone at the Hanford Site. This information will provide much needed data for the development of models of Tc mobility in the vadose zone following closure of the tank farms. With reliable models, a major cost reduction in remediation efforts may be achieved by selecting sites that present the greatest environmental threat and designing remediation methods with the greatest efficacy.
Download or read book Identification of the Non pertechnetate Species in Hanford Waste Tanks Tc I Carbonyl Complexes written by and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Immobilization of the high-level nuclear waste stored at the Hanford Reservation has been complicated by the presence of soluble, lower-valent technetium species. Previous work by Schroeder and Blanchard has shown that these species cannot be removed by ion-exchange and are difficult to oxidize. The Tc-K edge XANES spectra of the species in Tanks SY-101 and SY-103 were reported by Blanchard, but they could not be assigned to any known technetium complex. We report that the XANES spectra are most likely those of Tc(I) carbonyl species, especially fac-Tc(CO)3(gluconate)2−. This is further supported by EXAFS and 99Tc-NMR studies in nonradioactive simulants of these tank wastes.
Download or read book Experimental and Theoretical Approaches to Actinide Chemistry written by John K. Gibson and published by John Wiley & Sons. This book was released on 2018-03-19 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of contemporary actinide research that focuses on new advances in experiment and theory, and the interplay between these two realms Experimental and Theoretical Approaches to Actinide Chemistry offers a comprehensive review of the key aspects of actinide research. Written by noted experts in the field, the text includes information on new advances in experiment and theory and reveals the interplay between these two realms. The authors offer a multidisciplinary and multimodal approach to the nature of actinide chemistry, and explore the interplay between multiple experiments and theory, as well as between basic and applied actinide chemistry. The text covers the basic science used in contemporary studies of the actinide systems, from basic synthesis to state-of-the-art spectroscopic and computational techniques. The authors provide contemporary overviews of each topic area presented and describe the current and anticipated experimental approaches for the field, as well as the current and future computational chemistry and materials techniques. In addition, the authors explore the combination of experiment and theory. This important resource: Provides an essential resource the reviews the key aspects of contemporary actinide research Includes information on new advances in experiment and theory, and the interplay between the two Covers the basic science used in contemporary studies of the actinide systems, from basic synthesis to state-of-the-art spectroscopic and computational techniques Focuses on the interplay between multiple experiments and theory, as well as between basic and applied actinide chemistry Written for academics, students, professionals and researchers, this vital text contains a thorough review of the key aspects of actinide research and explores the most recent advances in experiment and theory.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1993 with total page 1452 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research and Technology written by Goddard Space Flight Center and published by . This book was released on 1990 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INIS Atomindex written by and published by . This book was released on 1996 with total page 794 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radioactive Waste Forms for the Future written by Werner Lutze and published by North Holland. This book was released on 1988 with total page 802 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents a compilation of important information on the full range of radioactive waste forms that have been developed, or at least suggested, for the incorporation of high-level nuclear waste. Many of the results were published in the ''gray literature'' of final reports of national laboratories or in various, generally less available, proceedings volumes. This is the first publication to draw information on nuclear waste forms for high-level wastes together into a single volume. Although borosilicate glass has become the standard waste form, additional research in this compound is still necessary. With improved technology (particularly processing technologies) and with a more detailed knowledge of repository conditions, glasses and second generation waste forms with improved performance properties can be developed. Sustained research programs on nuclear waste form development will yield results that can only add to public confidence and the final, safe disposal of nuclear waste. The aim of this volume is to provide a 'spring board' for these future research efforts. A detailed presentation is given on the properties and performance of non-crystalline waste forms (borosilicate glass, sintered glass, and lead-iron phosphate glass), and crystalline waste forms (Synroc, tailored ceramics, TiO 2 - ceramic matrix, glass-ceramics and FUETAP concrete). A chapter on Novel Waste Forms reviews a number of methods that warrant further development because of their potential superior performance and unique applications. The final chapter includes a tabulated comparison of important waste form properties and an extended discussion on the corrosion process and radiation damage effects for each waste form. Of particular interest is a performance assessment of nuclear waste borosilicate glass and the crystalline ceramic Synroc. This is the first detailed attempt to compare these two important waste forms on the basis of their materials properties. The discussion emphasizes the difficulties in making such a comparison and details the types of data that are required. Each chapter has been written by an expert and includes a current compilation of waste form properties with an extensive list of references. This volume will provide a stimulus for future research as well as useful reference material for scientists working in the field of nuclear waste disposal and materials science.
Download or read book Application of Ion Exchange Processes for the Treatment of Radioactive Waste and Management of Spent Ion Exchangers written by and published by . This book was released on 2002 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ion exchange is one of the most common and effective treatment methods for liquid radioactive waste. This book reviews the current literature on the subject and reports on the existing state of the art of the application of ion exchange processes for liquid radioactive waste treatments and of the management of spent ion exchange media.
