Download or read book Thermal History and Crystallization Characteristics of the DWPF Glass Waste Form written by and published by . This book was released on 1992 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Defense Waste Processing Facility (DWPF) at the Savannah River Site will immobilize high-level radioactive waste by incorporating it in a stable borosilicate glass waste form suitable for long term storage in a geologic repository. The thermal history of the canistered waste form to be produced in DWPF was determined during filling and subsequent cooldown operations by simulating DWPF production conditions. Samples of simulated waste glass of projected compositions for the DWPF have been exposed to the thermal regimen recorded during this simulation of canister production. These glass samples have been characterized using scanning electron microscopy to identify any crystalline phases that are present.

Download or read book Radioactive Waste Management written by and published by . This book was released on 1981 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Phase Stability Determinations of DWPF Waste Glasses Defense Waste Processing Facility written by and published by . This book was released on 1992 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The high-level radioactive wastes stored at Savannah River, will be immobilized in borosilicate glass in the Defense Waste Processing Facility (DWPF). Waste Acceptance Preliminary Specifications require that time-temperature-transformation (TTT) curves be provided for expected DWPF compositions, in order to predict the durability of the waste form. In order to derive these TTT curves, samples of simulated glasses are being heat treated and then analyzed. The seven simulated glasses include blend, high aluminum (HM) and high iron (Purex). X-ray diffraction show minimal crystallization for the heat treatments at 400, 1000 and 1100 C; 600 and 700 C produce the greatest amount of crystallization. Scanning electron microscopy show heterogeneous crystallization with the spinel forming on melt insolubles and the acmite nucleating on the spinel. Initial leaching results show that the glass durability decreases with increasing crystallinity for the 700 C glasses. Future plans are outlined. 2 tables, 9 refs. (DLC).

Download or read book High Level Radioactive Waste Management written by and published by . This book was released on 1992 with total page 1248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ASCE Combined Index written by American Society of Civil Engineers and published by . This book was released on 1993 with total page 916 pages. Available in PDF, EPUB and Kindle. Book excerpt: Indexes materials appearing in the Society's Journals, Transactions, Manuals and reports, Special publications, and Civil engineering.

Download or read book Government Reports Annual Index written by and published by . This book was released on 1992 with total page 1848 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Impacts of Small Column Ion Exchange Streams on DWPF Glass Formulation written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report is the fourth in a series of studies of the impacts of the addition of Crystalline Silicotitanate (CST) and Monosodium Titanate (MST) from the Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) glass waste form and the applicability of the DWPF process control models. MST from the Salt Waste Processing Facility (SWPF) is also considered in the study. The KT08-series of glasses was designed to evaluate any impacts of the inclusion of uranium and thorium in glasses containing the SCIX components. The KT09-series of glasses was designed to study the effect of increasing Al2O3 and K2O concentrations on the propensity for crystallization of titanium containing phases in high TiO2 concentration glasses. Earlier work on the KT05-series glasses recommended that the impact of these two components be studied further. Increased Al2O3 concentrations have been shown to improve the properties and performance of high waste loading glasses, and K2O has been reported to improve the retention of TiO2 in silicate glasses. The KT10-series of compositions was designed to evaluate any impacts of the SCIX components at concentrations 50% higher than currently projected.a The glasses were fabricated in the laboratory and characterized to identify crystallization, to verify chemical compositions, to measure viscosity, and to measure durability. Liquidus temperature measurements for the KT10-series glasses are underway and will be reported separately. All but one of the KT08-series glasses were found to be amorphous by X-ray diffraction (XRD). One of the slowly cooled glasses contained a small amount of trevorite, which had no practical impact on the durability of the glass and is typically found in DWPF-type glasses. The measured Product Consistency Test (PCT) responses for the KT08-series glasses are well predicted by the DWPF models. The viscosities of the KT08-series glasses were generally well predicted by the DWPF model. No unexpected issues were encountered when uranium and thorium were added to the glasses with SCIX components. Increased Al2O3 concentrations were not successful in preventing the formation of iron titanate crystals in the KT09-series glasses. Increased K2O concentrations were successful in hindering the formation of iron titanates in some of the glasses after the canister centerline cooled (CCC) heat treatment. However, this result did not apply to all of the CCC versions of the glasses, indicating a compositional dependence of this effect. In addition, high concentrations of K2O have been shown to hinder the ability of the DWPF durability and viscosity models to predict the performance of these glasses. The usefulness of increased K2O concentrations in preventing the formation of iron titanates may therefore be limited. Further characterization was not performed for the KT09-series glasses since the type of crystallization formed was the characteristic of interest for these compositions. All of the KT10-series glasses were XRD amorphous, regardless of heat treatment. Chemical composition measurements showed that the glasses met the targeted concentrations for each oxide. In general, the measured PCT responses of the KT10-series glasses were well predicted by the DWPF models. The measured, normalized release values for silicon for some of the glasses fell above the 95% confidence interval for the predicted values; however, the PCT responses for these glasses remain considerably lower than that of the benchmark Environmental Assessment (EA) glass. The viscosities of the KT10-series glasses were generally well predicted by the DWPF model. The next step in this study will be to compile all of the data developed and further compare the measured properties and performance with those predicted by the current DWPF Product Composition Control System (PCCS) models. Recommendations will then be made as to which models, if any, may need to be modified in order to accommodate the material from SCIX into DWPF glass production.

Download or read book IMPACTS OF SMALL COLUMN ION EXCHANGE STREAMS ON DWPF GLASS FORMULATION KT07 SERIES GLASS COMPOSITIONS written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report is the third in a series of studies of the impacts of the addition of Crystalline Silicotitanate (CST) and Monosodium Titanate (MST) from the Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) glass waste form and the applicability of the DWPF process control models. MST from the Salt Waste Processing Facility is also considered in the study. The KT07-series glasses were selected to evaluate any potential impacts of noble metals on their properties and performance. The glasses characterized thus far for the SCIX study have not included noble metals since they are not typically tracked in sludge batch composition projections. However, noble metals can act as nucleation sites in glass melts, leading to enhanced crystallization. This crystallization can potentially influence the properties and performance of the glass, such as chemical durability, viscosity, and liquidus temperature. The noble metals Ag, Pd, Rh, and Ru were added to the KT07-series glasses in concentrations based on recent measurements of Sludge Batch 6, which was considered to contain a high concentration of noble metals. The KT04-series glasses were used as the baseline compositions. After fabrication, the glasses were characterized to determine their homogeneity, chemical composition, durability, and viscosity. Liquidus temperature measurements are also underway but were not complete at the time of this report. The liquidus temperature results for the KT07-series glasses, along with several of the earlier glasses in the SCIX study, will be documented separately. All of the KT07-series glasses, both quenched and slowly cooled, were found to be amorphous by X-ray diffraction. Chemical composition measurements showed that all of the glasses met their targeted compositions. The Product Consistency Test (PCT) results showed that all of the glasses had chemical durabilities that were far better than that of the Environmental Assessment benchmark glass. The measured PCT responses were well predicted by the current DWPF Product Composition Control System (PCCS) durability models. The measured viscosity values for each KT07-series glass were acceptable for DWPF processing and were well predicted by the current PCCS model. Overall, the results show that the inclusion of relatively high concentrations of noble metals (in terms of expected values for a DWPF sludge batch) had no significant impact on the properties and performance of these glass compositions. There were no significant differences in the measured properties when compared to those of the KT04-series glasses, which did not contain noble metals. Liquidus temperature measurements are still underway and there may be an impact of the noble metals on those measurements. However, no adverse effects were noted in terms of crystallization after slow cooling. At the completion of these studies, all of the data generated will be reviewed with regard to the applicability of the DWPF PCCS models and recommendations will be made as to whether the validation ranges of the current models can be extended, or whether some or all of the models need to be refit to allow for the incorporation of the SCIX streams. As changes are made to the projected sludge compositions and the volume of the SCIX material, additional evaluations should be performed.

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1992-12 with total page 2022 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book IMPACTS OF SMALL COLUMN ION EXCHANGE STREAMS ON DWPF GLASS FORMULATION written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report is the second in a series of studies of the impacts of the addition of Crystalline Silicotitanate (CST) and Monosodium Titanate (MST) from the Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) glass waste form and the applicability of the DWPF process control models. The KT05-series glasses were selected, fabricated, and characterized to further study glass compositions where iron titanate crystals had been previously found to form. The intent was to better understand the mechanisms and compositions that favored the formation of crystals containing titanium. Formation of these crystalline phases was confirmed. Increased Na2O concentrations had little if any impact on reducing the propensity for the formation of the iron titanate crystalline phases. Other physical properties of these glasses were not measured since the intent was to focus on crystallization. Additional studies are suggested to investigate the potential impacts of Al2O3 and K2O on crystallization in glasses with high TiO2 concentrations. The KT06-series glasses were selected, fabricated, and characterized to further study glass compositions that, while broader than the current projections for DWPF feeds with SCIX material, are potential candidates for future processing (i.e., the compositions are acceptable for processing by the Product Composition Control System (PCCS) with the exception of the current TiO2 concentration constraint). The chemical compositions of these glasses matched well with the target values. The chemical durabilities of all the glasses were acceptable relative to the Environmental Assessment (EA) benchmark. Minor crystallization was identified in some of the slowly cooled glasses, although this crystallization did not impact chemical durability. Several of the KT06-series compositions had durability values that, while acceptable, were not accurately predicted by the current durability models. It was shown that for these high TiO2 concentration glasses, relatively high Fe2O3 concentrations combined with relatively high Al2O3 concentrations led to durabilities that were unpredictable. Several of the KT06-series glasses also had measured viscosity values that were not well predicted by the current model. A statistical partitioning routine showed that the measured viscosities became unpredictable by the current model when the Fe2O3 concentration in the glasses was less than about 8.2 wt % at the elevated TiO2 concentrations. The current durability and viscosity models will have to be further evaluated should compositions in these regions become necessary for DWPF processing. Overall, the results presented for the KT06-series glasses show that TiO2 from the SCIX streams can be incorporated into DWPF-type glasses at concentrations of 6 wt % (in glass) without any detrimental impacts on crystallization or chemical durability that are of practical importance. The measured values for chemical durability and viscosity were acceptable for processing; however, not all of the values were predictable by the current PCCS models. Since the compositions selected for the KT06-series glasses were outside the current projections for DWPF processing with the SCIX streams (in terms of waste components other than TiO2), these results help identify compositional regions that, if necessary for processing, would require modifications to the current models. Additional experiments are currently underway. Once completed, all of the measured data will be reviewed and compared to model predictions to better determine whether the validation range of the DWPF process control models can be confidently extended, or whether refitting of the models will be necessary.

Download or read book Time Temperature Transformation Diagrams for DWPF Projected Glass Compositions written by and published by . This book was released on 1993 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Department of Energy's Waste Acceptance Product Specifications (WAPS) require that time-temperature-transformation diagrams be developed for each of the DWPF high-level waste glass compositions. This information will be useful in understanding the crystallization behavior during melter idling, accident scenarios, and storage. Simulated high level waste glass samples were annealed at temperatures varying from 400-1100°C for times varying from 45 minutes to 32 days. The glasses were characterized by x-ray diffraction to identify and quantify the crystalline phases present. The results were used to construct the diagrams.

Download or read book Hydrothermal Crystallization of a Radioactive Waste Storage Glass written by D. Savage and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Melter Residence Time and Temperature on Defense Waste Processing Facility Glass Durability written by and published by . This book was released on 1994 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Defense Waste Processing Facility (DWPF) located at the Savannah River Site (SRS) in Aiken, South Carolina, is currently scheduled to vitrify more than 130 million liters of High Level Waste (HLW). The glass product that will be produced must meet certain specifications, as defined in the Waste Acceptance Product Specifications (WAPS), in order for the DWPF canistered waste forms to be sent to the Civilian Radioactive Waste Management System (repository). WAPS 1.3 requires that the DWPF produce a consistent product, which is better than the Environmental Assessment (EA) glass as measured by the B, Na, and Li release from the Product Consistency Test (PCT).

Download or read book Strategy and Methodology for Radioactive Waste Characterization written by International Atomic Energy Agency and published by IAEA. This book was released on 2007 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past decade significant progress has been achieved in the development of waste characterization and control procedures and equipment as a direct response to ever-increasing requirements for quality and reliability of information on waste characteristics. Failure in control procedures at any step can have important, adverse consequences and may result in producing waste packages which are not compliant with the waste acceptance criteria for disposal, thereby adversely impacting the repository. The information and guidance included in this publication corresponds to recent achievements and reflects the optimum approaches, thereby reducing the potential for error and enhancing the quality of the end product. -- Publisher's description.

Download or read book Waste Forms Technology and Performance written by National Research Council and published by National Academies Press. This book was released on 2011-09-05 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

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