Download or read book INTERNATIONAL STUDY OF ALUMINUM IMPACTS ON CRYSTALLIZATION IN U S HIGH LEVEL WASTE GLASS written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this task was to develop glass formulations for (Department of Energy) DOE waste streams with high aluminum concentrations to avoid nepheline formation while maintaining or meeting waste loading and/or waste throughput expectations as well as satisfying critical process and product performance related constraints. Liquidus temperatures and crystallization behavior were carefully characterized to support model development for higher waste loading glasses. The experimental work, characterization, and data interpretation necessary to meet these objectives were performed among three partnering laboratories: the V.G. Khlopin Radium Institute (KRI), Pacific Northwest National Laboratory (PNNL) and Savannah River National Laboratory (SRNL). Projected glass compositional regions that bound anticipated Defense Waste Processing Facility (DWPF) and Hanford high level waste (HLW) glass regions of interest were developed and used to generate glass compositions of interest for meeting the objectives of this study. A thorough statistical analysis was employed to allow for a wide range of waste glass compositions to be examined while minimizing the number of glasses that had to be fabricated and characterized in the laboratory. The glass compositions were divided into two sets, with 45 in the test matrix investigated by the U.S. laboratories and 30 in the test matrix investigated by KRI. Fabrication and characterization of the US and KRI-series glasses were generally handled separately. This report focuses mainly on the US-series glasses. Glasses were fabricated and characterized by SRNL and PNNL. Crystalline phases were identified by X-ray diffraction (XRD) in the quenched and canister centerline cooled (CCC) glasses and were generally iron oxides and spinels, which are not expected to impact durability of the glass. Nepheline was detected in five of the glasses after the CCC heat treatment. Chemical composition measurements for each of the glasses were conducted following an analytical plan. A review of the individual oxides for each glass revealed that there were no errors in batching significant enough to impact the outcome of the study. A comparison of the measured compositions of the replicates indicated an acceptable degree of repeatability as the percent differences for most of the oxides were less than 5% and percent differences for all of the oxides were less than 10 wt%. Chemical durability was measured using the Product Consistency Test (PCT). All but two of the study glasses had normalized leachate for boron (NL [B]) values that were well below that of the Environmental Assessment (EA) reference glass. The two highest NL [B] values were for the CCC versions of glasses US-18 and US-27 (10.498 g/L and 15.962 g/L, respectively). Nepheline crystallization was identified by qualitative XRD in five of the US-series glasses. Each of these five glasses (US-18, US-26, US-27, US-37 and US-43) showed a significant increase in NL [B] values after the CCC heat treatment. This reduction in durability can be attributed to the formation of nepheline during the slow cooling cycle and the removal of glass formers from the residual glass network. The liquidus temperature (T{sub L}) of each glass in the study was determined by both optical microscopy and XRD methods. The correlation coefficient of the measured XRD TL data versus the measured optical TL data was very good (R2 = 0.9469). Aside from a few outliers, the two datasets aligned very well across the entire temperature range (829 C to 1312 C for optical data and 813 C to 1310 C for XRD crystal fraction data). The data also correlated well with the predictions of a PNNL T{sub L} model. The correlation between the measured and calculated data had a higher degree of merit for the XRD crystal fraction data than for the optical data (higher R2 value of 0.9089 versus 0.8970 for the optical data). The SEM-EDS analysis of select samples revealed the presence of undissolved RuO2 in all glasses due to the low solubility of RuO2 in borosilicate glass. These particles tended to form agglomerates with varying sizes and shapes that were located close to the bottom of crucibles. The results of this study provide further insight into the ability of borosilicate waste glass to incorporate increased (>16 wt %) concentrations of aluminum. The glass composition and properties data will be incorporated into a database of glass composition-property relationships (ComPro) to support further optimization of waste glass compositions at DOE sites.

Download or read book Advances in Materials Science for Environmental and Nuclear Technology written by Kevin M. Fox and published by John Wiley & Sons. This book was released on 2010-10-01 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Materials Science and Technology 2009 Conference and Exhibition (MS&T’09) was held October 25-29, 2009, in Pittsburgh, Pennsylvania. A major theme of the conference was Environmental and Energy Issues. Papers from three of the symposia held under that theme are included in this volume. These symposia include Materials Solutions for the Nuclear Renaissance; Green Engineering and Environmental Stewardship; and Nanotechnology for Energy. These symposia included a variety of presentations with sessions focused on sustainable energy, photovoltaics, nanowires and composites, energy harvesting, catalysts, thin films, corrosion, nuclear fuels, materials in aggressive environments, glass and ceramics for waste disposition, modeling and thermal properties, and education. Also included was a series of invited presentations and an international panel discussion on cement waste forms. The Green Engineering and Environmental Stewardship symposium was sponsored by the Nuclear and Environmental Technology Division (NETD) of The American Ceramic Society while the Materials Solutions for the Nuclear Renaissance symposium was sponsored by NETD and ASM International.

Download or read book Advances in Materials Science for Environmental and Energy Technologies II written by Josef Matyáš and published by John Wiley & Sons. This book was released on 2013-08-12 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings contains a collection of 24 papers from five 2012Materials Science and Technology (MS&T’12)symposia. Green Technologies for Materials Manufacturing and ProcessingIII Materials Development for Nuclear Applications and ExtremeEnvironments Materials Issues in Nuclear Waste Management in the21st Century Energy Conversion – Photovoltaic, Concentrating SolarPower, and Thermoelectric Energy Storage: Materials, Systems and Applications

Download or read book Crystallization in Simulated Glasses from Hanford High level Nuclear Waste Composition Range written by and published by . This book was released on 1993 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Glass crystallization was investigated as part of a property-composition relationship study of Hanford waste glasses. Non-radioactive glass samples were heated in a gradient furnace over a wide range of temperatures. The liquidus temperature was measured, and primary crystalline phases were determined using optical microscopy and Scanning Electron Microscopy with Energy Dispersive Spectrometry (SEM/EDS). Samples have also been heat treated according to a simulated canister centerline cooling curve. The crystalline phases in these samples have been identified by optical microscopy, SEM/EDS, and X-ray diffraction (XRD). Major components of the borosilicate glasses that were melted at approximately 1150°C were SiO2, B2O3, Na2O, Li2O, CaO, MgO, Fe2O3, Al2O3, ZrO2, and ''Others'' (sum of minor components). The major crystalline phases identified in this study were zircon, nepheline, calcium silicate, lithium silicate, and a range of solid solutions from clinopyroxenes, orthopyroxenes, olivines, and spiners.

Download or read book CRYSTALLIZATION IN HIGH LEVEL WASTE GLASSES U S DEPARTMENT OF ENERGY OFFICE OF RIVER PROTECTION WTP ENGINEERING DIVISION written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Various circumstances influence crystallization in glassmaking, for example: (1) crystals nucleate and grow before the glass-forming melt occurs; (2) crystals grow or dissolve in flowing melt and during changing temperature; (3) crystals move under the influence of gravity; (4) crystals agglomerate and interact with gas bubbles; (5) high-level wastes (HLW) are mixtures of a large number of components in unusual proportions; (6) melter processing of HLW and the slow cooling of HLW glass in canisters provides an opportunity for a variety of crystalline forms to precipitate; (7) settling of crystals in a HLW glass melter may produce undesirable sludge at the melter bottom; and (8) crystallization of the glass product may increase, but also ruin chemical durability. The conclusions are: (1) crystal growth and dissolution typically proceed in a convective medium at changing temperature; (2) to represent crystallization or dissolution the kinetics must be expressed in the form of rate equations, such as dC/dt = f(C, T) and the temperature dependence of kinetic coefficients and equilibrium concentrations must be accounted for; and (3) non-equilibrium phenomena commonly occur - metastable crystallization, periodic distribution of crystals; and dendritic crystal growth.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Environmental Issues and Waste Management Technologies in the Materials and Nuclear Industries XII written by Alex Cozzi and published by John Wiley & Sons. This book was released on 2009-09-24 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book documents a special collection of articles from a select group of invited prominent scientists from academia, national laboratories and industry who presented their work at the symposia on Environmental and Energy Issues at the 2008 Materials Science and Technology (MS&T’08) conference held in Pittsburgh, PA. These articles represent a summary of the presentations focusing on topics in nuclear, environmental, and green engineering were held, including a discussion of Waste Glass Leach Testing and Modeling.

Download or read book Crystallization in High level Waste Glass written by and published by . This book was released on 2015 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a fundamental need to continue research aimed at understanding nepheline and spinel crystal formation in high-level waste (HLW) glass. Specifically, the formation of nepheline solids (K/NaAlSiO4) during slow cooling of HLW glass can reduce the chemical durability of the glass, which can cause a decrease in the overall durability of the glass waste form. The accumulation of spinel solids ((Fe, Ni, Mn, Zn)(Fe, Cr)2O4), while not detrimental to glass durability, can cause an array of processing problems inside HLW glass melters. In this review, the fundamental differences between glass and solid-crystals are explained using kinetic, thermodynamic, and viscosity arguments, and several highlights of glass-crystallization research, as it pertains to high-level waste vitrification, are described. In terms of mitigating spinel in the melter and both spinel and nepheline formation in the canister, the complexity of HLW glass and the intricate interplay between thermal, chemical, and kinetic factors further complicates this understanding. However, new experiments seeking to elucidate the contributing factors of crystal nucleation and growth in waste glass, and the compilation of data from older experiments, may go a long way towards helping to achieve higher waste loadings while developing more efficient processing strategies. Higher waste loadings and more efficient processing strategies will reduce the overall HLW Hanford Tank Waste Treatment and Immobilization Plant (WTP) vitrification facilities mission life.

Download or read book Handbook of Advanced Radioactive Waste Conditioning Technologies written by Michael I. Ojovan and published by Elsevier. This book was released on 2011-01-24 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radioactive wastes are generated from a wide range of sources, including the power industry, and medical and scientific research institutions, presenting a range of challenges in dealing with a diverse set of radionuclides of varying concentrations. Conditioning technologies are essential for the encapsulation and immobilisation of these radioactive wastes, forming the initial engineered barrier required for their transportation, storage and disposal. The need to ensure the long term performance of radioactive waste forms is a key driver of the development of advanced conditioning technologies. The Handbook of advanced radioactive waste conditioning technologies provides a comprehensive and systematic reference on the various options available and under development for the treatment and immobilisation of radioactive wastes. The book opens with an introductory chapter on radioactive waste characterisation and selection of conditioning technologies. Part one reviews the main radioactive waste treatment processes and conditioning technologies, including volume reduction techniques such as compaction, incineration and plasma treatment, as well as encapsulation methods such as cementation, calcination and vitrification. This coverage is extended in part two, with in-depth reviews of the development of advanced materials for radioactive waste conditioning, including geopolymers, glass and ceramic matrices for nuclear waste immobilisation, and waste packages and containers for disposal. Finally, part three reviews the long-term performance assessment and knowledge management techniques applicable to both spent nuclear fuels and solid radioactive waste forms. With its distinguished international team of contributors, the Handbook of advanced radioactive waste conditioning technologies is a standard reference for all radioactive waste management professionals, radiochemists, academics and researchers involved in the development of the nuclear fuel cycle. Provides a comprehensive and systematic reference on the various options available and under development for the treatment and immobilisation of radioactive wastes Explores radioactive waste characterisation and selection of conditioning technologies including the development of advanced materials for radioactive waste conditioning Assesses the main radioactive waste treatment processes and conditioning technologies, including volume reduction techniques such as compaction

Download or read book Optical Basicity and Nepheline Crystallization in High Alumina Glasses written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this study was to find compositions that increase waste loading of high-alumina wastes beyond what is currently acceptable while avoiding crystallization of nepheline (NaAlSiO4) on slow cooling. Nepheline crystallization has been shown to have a large impact on the chemical durability of high-level waste glasses. It was hypothesized that there would be some composition regions where high-alumina would not result in nepheline crystal production, compositions not currently allowed by the nepheline discriminator. Optical basicity (OB) and the nepheline discriminator (ND) are two ways of describing a given complex glass composition. This report presents the theoretical and experimental basis for these models. They are being studied together in a quadrant system as metrics to explore nepheline crystallization and chemical durability as a function of waste glass composition. These metrics were calculated for glasses with existing data and also for theoretical glasses to explore nepheline formation in Quadrant IV (passes OB metric but fails ND metric), where glasses are presumed to have good chemical durability. Several of these compositions were chosen, and glasses were made to fill poorly represented regions in Quadrant IV. To evaluate nepheline formation and chemical durability of these glasses, quantitative X-ray diffraction (XRD) analysis and the Product Consistency Test were conducted. A large amount of quantitative XRD data is collected here, both from new glasses and from glasses of previous studies that had not previously performed quantitative XRD on the phase assemblage. Appendix A critically discusses a large dataset to be considered for future quantitative studies on nepheline formation in glass. Appendix B provides a theoretical justification for choice of the oxide coefficients used to compute the OB criterion for nepheline formation.

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 Compositional Dependence of Glass Corrosion Due to the Crystallization of Nepheline written by Jose Marcial and published by . This book was released on 2017 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vitrification of Hanford high-level nuclear waste is a complex process, which is of great significance to those residing in the state of Washington. One characteristic of the vitrified product, the chemical durability, can be high impacted by the deleterious crystallization of aluminosilicates and lead to a large decrease in the corrosion resistance of the vitrified product. Therefore, this work seeks to understand the influence of starting glass composition on the crystallization behavior of quaternary, quinary, and complex glasses. Techniques employed through with work include X-ray diffraction, Raman Spectroscopy, electron probe microanalysis, nuclear magnetic resonance, and synchrotron X-ray and neutron total scattering. It was determined that nepheline composition and microstructure was influence by starting melt composition and heat treatment temperature schedule. Additionally, mixed alkali effects influence crystallization extent and phase assemblage, boron speciation varies upon large fraction of crystallization, and a comparison of cation coordination number between glass and crystalline reference offers a metric for crystallization behavior for a wide range of silicate glasses.

Download or read book Towards Increased Waste Loading in High Level Waste Glasses written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A number of waste components in US defense high level radioactive wastes (HLW) have proven challenging for current Joule heated ceramic melter (JHM) operations and have limited the ability to increase waste loadings beyond already realized levels. Many of these "troublesome" waste species cause crystallization in the glass that can negatively impact product quality or have a deleterious effect on melter processing. Recent efforts at US Department of Energy laboratories have focused on understanding crystallization behavior within HLW glasses and investigating approaches to mitigate the impacts of crystallization so that increases in waste loading can be realized. Advanced glass formulations have been developed to highlight the unique benefits of next-generation melter technologies such as the Cold Crucible Induction Melter (CCIM). Crystal-tolerant HLW glasses have been investigated to allow sparingly soluble components such as chromium to crystallize in the melter but pass out of the melter before accumulating. The Hanford site AZ-101 composition represents a waste group that is waste loading limited primarily due to high concentration of Fe2O3. Systematic glass formulation development utilizing slightly higher process temperatures and higher tolerance to spinel crystals demonstrated that an increase in waste loading of more than 20% could be achieved for this waste group.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book QUALIFICATION OF A RADIOACTIVE HIGH ALUMINUM GLASS FOR PROCESSINGIN THE DEFENSE WASTE PROCESSING FACILITY AT THE SAVANNAH RIVER SITE written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: At the Savannah River Site (SRS) the Defense Waste Processing Facility (DWPF) has been immobilizing SRS's radioactive high level waste (HLW) sludge into a borosilicate glass for approximately eleven years. Currently the DWPF is immobilizing HLW sludge in Sludge Batch 4 (SB4). Each sludge batch is nominally two million liters of HLW and produces nominally five hundred stainless steel canisters 0.6 meters in diameter and 3 meters tall filled with the borosilicate glass. In SB4 and earlier sludge batches, the Al concentration has always been rather low, (less than 9.5 weight percent based on total dried solids). It is expected that in the future the Al concentrations will increase due to the changing composition of the HLW. Higher Al concentrations could introduce problems because of its known effect on the viscosity of glass melts and increase the possibility of the precipitation of nepheline in the final glass and decrease its durability. In 2006 Savannah River National Laboratory (SRNL) used DWPF processes to immobilize a radioactive HLW slurry containing 14 weight percent Al to ensure that this waste is viable for future DWPF processing. This paper presents results of the characterization of the high Al glass prepared in that demonstration. At SRNL, a sample of the processed high Al HLW slurry was mixed with an appropriate glass frit as performed in the DWPF to make a waste glass containing nominally 30% waste oxides. The glass was prepared by melting the frit and waste remotely at 1150 C. The glass was then characterized by: (1) determining the chemical composition of the glass including the concentrations of several actinide and U-235 fission products; (2) calculating the oxide waste loading of the glass based on the chemical composition and comparing it to that of the target; (3) determining if the glass composition met the DWPF processing constraints such as glass melt viscosity and liquidus temperature along with a waste form affecting constraint that prevents the precipitation of nepheline (NaAlSiO4) crystals in the glass melt; (4) measuring the durability of the glass using the ASTM Standard Product Consistency Test (PCT) leach test to determine if the durability of the glass based on B, Li, and Na releases met the requirements for acceptance in a US geologic repository; (5) measuring the leachability of several radionuclides using the ASTM Standard PCT leach test and comparing them to the B, Li, and Na releases; and (6) examining the glass by scanning electron microscopy and energy dispersive X-ray spectrometry to determine if any crystals had formed in the glass melt. Results indicate that the high Al glass met all the requirements for processing and product quality in the DWPF.

Download or read book Research Needs for High Level Waste Stored in Tanks and Bins at U S Department of Energy Sites written by National Research Council and published by National Academies Press. This book was released on 2001-10-05 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States Department of Energy (DOE) has approximately 400 million liters (100 million gallons) of liquid high-level waste (HLW) stored in underground tanks and approximately 4,000 cubic meters of solid HLW stored in bins. The current DOE estimate of the cost of converting these liquid and solid wastes into stable forms for shipment to a geological repository exceeds $50 billion to be spent over several decades (DOE, 2000). The Committee on Long-Term Research Needs for Radioactive High-Level Waste at Department of Energy Sites was appointed by the National Research Council (NRC) to advise the Environmental Management Science Program (EMSP) on a long-term research agenda addressing the above problems related to HLW stored in tanks and bins at DOE sites.

Download or read book Radioactive Waste Processing and Disposal written by U.S. Nuclear Regulatory Commission and published by . This book was released on 1980 with total page 908 pages. Available in PDF, EPUB and Kindle. Book excerpt: