Download or read book Glass Fabrication and Product Consistency Testing of Lanthanide Borosilicate Glass for Plutonium Disposition written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Department of Energy Office of Environmental Management (DOE/EM) plans to conduct the Plutonium Disposition Project at the Savannah River Site (SRS) in Aiken, SC, to disposition excess weapons-usable plutonium. A plutonium glass waste form is a leading candidate for immobilization of the plutonium for subsequent disposition in a geologic repository. The objectives of this present task were to fabricate plutonium-loaded lanthanide borosilicate (LaBS) Frit B glass and perform testing to provide near-term data that will increase confidence that LaBS glass product is suitable for disposal in the proposed Federal Repository. Specifically, testing was conducted in an effort to provide data to Yucca Mountain Project (YMP) personnel for use in performance assessment calculations. Plutonium containing LaBS glass with the Frit B composition with a 9.5 wt% PuO2 loading was prepared for testing. Glass was prepared to support glass durability testing via the ASTM Product Consistency Testing (PCT) at Savannah River National Laboratory (SRNL). The glass was characterized with X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) prior to performance testing. This characterization revealed some crystalline PuO2 inclusions with disk-like morphology present in the as fabricated, quench-cooled glass. A series of PCTs was conducted at SRNL with varying exposed surface area and test durations. Filtered leachates from these tests were analyzed to determine the dissolved concentrations of key elements. The leachate solutions were also ultrafiltered to quantify colloid formation. Leached solids from select PCTs were examined in an attempt to evaluate the Pu and neutron absorber release behavior from the glass and to investigate formation of alteration phases on the glass surface. A series of PCTs was conducted at 90 C in ASTM Type 1 water to compare the Pu LaBS Frit B glass durability to current requirements for High Level Waste (HLW) glass in a geologic repository. The PCT (7-day static test with powdered glass) results on the Pu-containing LaBS Frit B glass at SA/V of ≈ 2000 m−1 showed that the glass was very durable with an average normalized elemental release value for boron of 0.013 g/m2. This boron release value is ≈ 640X lower than normalized boron release from current Environmental Assessment (EA) glass used for repository acceptance. The PCT-B (7, 14, 28 and 56-day, static test with powdered glass) normalized elemental releases were similar to the normalized elemental release values from PCT-A testing, indicating that the LaBS Frit B glass is very durable as measured by the PCT. Normalized plutonium releases were essentially the same within the analytical uncertainty of the ICP-MS methods used to quantify plutonium in the 0.45 [mu]m-filtered leachates and ultra-filtered leachates, indicating that colloidal plutonium species do not form under the PCT conditions used in this study.

Download or read book GLASS FABRICATION AND PRODUCT CONSISTENCY TESTING OF LANTHANIDE BOROSILICATE FRIT B COMPOSITION FOR PLUTONIUM DISPOSITION written by J. Marra and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Department of Energy Office of Environmental Management (DOE/EM) plans to conduct the Plutonium Disposition Project at the Savannah River Site (SRS) to disposition excess weapons-usable plutonium. A plutonium glass waste form is a leading candidate for immobilization of the plutonium for subsequent disposition in a geologic repository. A reference glass composition (Lanthanide Borosilicate (LaBS) Frit B) was developed during the Plutonium Immobilization Program (PIP) to immobilize plutonium. A limited amount of performance testing was performed on this baseline composition before efforts to further pursue Pu disposition via a glass waste form ceased. Therefore, the objectives of this present task were to fabricate plutonium loaded LaBS Frit B glass and perform additional testing to provide near-term data that will increase confidence that LaBS glass product is suitable for disposal in the Yucca Mountain Repository. Specifically, testing was conducted in an effort to provide data to Yucca Mountain Project (YMP) personnel for use in performance assessment calculations. Plutonium containing LaBS glass with the Frit B composition with a 9.5 wt% PuO{sub 2} loading was prepared for testing. Glass was prepared to support Product Consistency Testing (PCT) at Savannah River National Laboratory (SRNL) and for additional performance testing at Argonne National Laboratory (ANL) and Pacific Northwest National Laboratory (PNNL). The glass was characterized using x-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) prior to performance testing. A series of PCTs were conducted at SRNL with varying exposed surface area and test durations. The leachates from these tests were analyzed to determine the dissolved concentrations of key elements. Acid stripping of leach vessels was performed to determine the concentration of the glass constituents that may have sorbed on the vessels during leach testing. Additionally, the leachate solutions were ultrafiltered to quantify colloid formation. The leached solids from select PCTs were examined in an attempt to evaluate the Pu and neutron absorber release behavior from the glass and to identify the formation of alteration phases on the glass surface. Characterization of the glass prior to testing revealed that some undissolved plutonium oxide was present in the glass. The undissolved particles had a disk-like morphology and likely formed via coarsening of particles in areas compositionally enriched in plutonium. Similar disk-like PuO{sub 2} phases were observed in previous LaBS glass testing at PNNL. In that work, researchers concluded that plutonium formed with this morphology as a result of the leaching process. It was more likely that the presence of the plutonium oxide crystals in the PNNL testing was a result of glass fabrication. A series of PCTs were conducted at 90 C in ASTM Type 1 water. The PCT-Method A (PCT-A) was conducted to compare the Pu LaBS Frit B glass durability to current requirements for High Level Waste (HLW) glass in a geologic repository. The PCT-A test has a strict protocol and is designed to specifically be used to evaluate whether the chemical durability and elemental release characteristics of a nuclear waste glass have been consistently controlled during production and, thus, meet the repository acceptance requirements. The PCT-A results on the Pu containing LaBS Frit B glass showed that the glass was very durable with a normalized elemental release value for boron of approximately 0.02 g/L. This boron release value was better than two orders of magnitude better from a boron release standpoint than the current Environmental Assessment (EA) glass used for repository acceptance. The boron release value for EA glass is 16.7 g/L.

Download or read book GLASS FABRICATION AND PRODUCT CONSISTENCY TESTING OF LANTHANIDE BOROSILICATE FRIT X COMPOSITION FOR PLUTONIUM DISPOSITION written by J. Marra and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Department of Energy Office of Environmental Management (DOE/EM) plans to conduct the Plutonium Disposition Project at the Savannah River Site (SRS) to disposition excess weapons-usable plutonium. A plutonium glass waste form is the preferred option for immobilization of the plutonium for subsequent disposition in a geologic repository. A reference glass composition (Lanthanide Borosilicate (LaBS) Frit B) was developed during the Plutonium Immobilization Program (PIP) to immobilize plutonium in the late 1990's. A limited amount of performance testing was performed on this baseline composition before efforts to further pursue Pu disposition via a glass waste form ceased. Recent FY05 studies have further investigated the LaBS Frit B formulation as well as development of a newer LaBS formulation denoted as LaBS Frit X. The objectives of this present task were to fabricate plutonium loaded LaBS Frit X glass and perform corrosion testing to provide near-term data that will increase confidence that LaBS glass product is suitable for disposal in the Yucca Mountain Repository. Specifically, testing was conducted in an effort to provide data to Yucca Mountain Project (YMP) personnel for use in performance assessment calculations. Plutonium containing LaBS glass with the Frit X composition with a 9.5 wt% PuO{sub 2} loading was prepared for testing. Glass was prepared to support Product Consistency Testing (PCT) at Savannah River National Laboratory (SRNL). The glass was thoroughly characterized using x-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) prior to performance testing. A series of PCTs were conducted at SRNL using quenched Pu Frit X glass with varying exposed surface areas. Effects of isothermal and can-in-canister heat treatments on the Pu Frit X glass were also investigated. Another series of PCTs were performed on these different heat-treated Pu Frit X glasses. Leachates from all these PCTs were analyzed to determine the dissolved concentrations of key elements. Acid stripping of leach vessels was performed to determine the concentration of the glass constituents that may have sorbed on the vessels during leach testing. Additionally, the leachate solutions were ultrafiltered to quantify colloid formation.

Download or read book GLASS FABRICATION AND PRODUCT CONSISTENCY TESTING OF LANTHANIDE BOROSHILICATE FRIT X COMPOSITION FOR PLUTONIUM DISPOSITION written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Department of Energy Office of Environmental Management (DOE/EM) plans to conduct the Plutonium Disposition Project at the Savannah River Site (SRS) to disposition excess weapons-usable plutonium. A plutonium glass waste form is the preferred option for immobilization of the plutonium for subsequent disposition in a geologic repository. A reference glass composition (Lanthanide Borosilicate (LaBS) Frit B) was developed during the Plutonium Immobilization Program (PIP) to immobilize plutonium in the late 1990's. A limited amount of performance testing was performed on this baseline composition before efforts to further pursue Pu disposition via a glass waste form ceased. Recent FY05 studies have further investigated the LaBS Frit B formulation as well as development of a newer LaBS formulation denoted as LaBS Frit X. The objectives of this present task were to fabricate plutonium loaded LaBS Frit X glass and perform corrosion testing to provide near-term data that will increase confidence that LaBS glass product is suitable for disposal in the Yucca Mountain Repository. Specifically, testing was conducted in an effort to provide data to Yucca Mountain Project (YMP) personnel for use in performance assessment calculations. Plutonium containing LaBS glass with the Frit X composition with a 9.5 wt% PuO2 loading was prepared for testing. Glass was prepared to support Product Consistency Testing (PCT) at Savannah River National Laboratory (SRNL). The glass was thoroughly characterized using x-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) prior to performance testing. A series of PCTs were conducted at SRNL using quenched Pu Frit X glass with varying exposed surface areas. Effects of isothermal and can-in-canister heat treatments on the Pu Frit X glass were also investigated. Another series of PCTs were performed on these different heat-treated Pu Frit X glasses. Leachates from all these PCTs were analyzed to determine the dissolved concentrations of key elements. Acid stripping of leach vessels was performed to determine the concentration of the glass constituents that may have sorbed on the vessels during leach testing. Additionally, the leachate solutions were ultrafiltered to quantify colloid formation. Characterization of the quenched Pu Frit X glass prior to testing revealed that some crystalline plutonium oxide was present in the glass. The crystalline particles had a disklike morphology and likely formed via coarsening of particles in areas compositionally enriched in plutonium. Similar results had also been observed in previous Pu Frit B studies. Isothermal 1250 C heat-treated Pu Frit X glasses showed two different crystalline phases (PuO2 and Nd2Hf2O-- ), as well as a peak shift in the XRD spectra that is likely due to a solid solution phase PuO2-HfO2 formation. Micrographs of this glass showed a clustering of some of the crystalline phases. Pu Frit X glass subjected to the can-in-canister heating profile also displayed the two PuO2 and Nd2Hf2O-- phases from XRD analysis. Additional micrographs indicate crystalline phases in this glass were of varying forms (a spherical PuO2 phase that appeared to range in size from submicron to (almost equal to)5 micron, a dendritic-type phase that was comprised of mixed lanthanides and plutonium, and a minor phase that contained Pu and Hf), and clustering of the phases was also observed.

Download or read book Pu Glass Fabrication and Product Consistency Testing written by James Marra and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The DOE/EM plans to conduct the Plutonium Vitrification Project at the Savannah River Site (SRS). An important part of this project is to reduce the attractiveness of the plutonium by fabricating a plutonium glass form and immobilizing the Pu form within the high level waste (HLW) glass prepared in the Defense Waste Processing Facility (DWPF). This requires that a project schedule that is consistent with EM plans for DWPF and cleanup of the SRS be developed. Critical inputs to key decisions in the vitrification project schedule are near-term data that will increase confidence that lanthanide borosilicate (LaBS) glass product is suitable for disposal in the Yucca Mountain Repository. A workshop was held on April 28, 2005 at Bechtel SAIC Company facility in Las Vegas, NV to define the near term data needs. Dissolution rate data and the fate of plutonium oxide and the neutron absorbers during the dissolution process were defined as key data needs. A suite of short-term tests were defined at the workshop to obtain the needed data. The objectives of these short-term tests are to obtain data that can be used to show that the dissolution rate of a LaBS glass is acceptable and to show that the extent of Pu separation from neutron absorbers, as the glass degrades and dissolves, is not likely to lead to criticality concerns. An additional data need was identified regarding the degree of macroscopic cracking that occurs during processing of the Pu glass waste form and subsequent pouring of HLW glass in the DWPF. A final need to evaluate new frit formulations that may increase the durability of the plutonium glass and/or decrease the degree to which neutron absorbers separate from the plutonium during dissolution was identified. This task plan covers testing to support a near term data need regarding glass dissolution performance. Separate task plans will be developed for testing to address the degree of macroscopic cracking and the development of alternative frit formulations. The Product Consistency Test (PCT) was identified as a means to provide some of the near term performance data. The PCT is a static test method in which known masses of crushed glass and demineralized water are reacted for a desired duration [1]. There are two reasons to perform the PCT. The first is that the results are used as a measure of acceptance in the Waste Acceptance Product Specifications Document (WAPS) [2]. The second is the need for long-term static test results that can be used to verify the applicability of the degradation model. Thus, the primary focus will be on the use of the PCT Method B (PCT-B) to study the formation and stability of colloids and to study alteration phases formed on the glass surface. The standard 7-day PCT in demineralized water (PCT-A) will be included to demonstrate compliance with the waste acceptance criterion and determine the value of the k{sub E} rate parameter for comparison with the Defense HLW Glass Degradation Model [3].

Download or read book Waste Immobilization in Glass and Ceramic Based Hosts written by Ian W. Donald and published by John Wiley & Sons. This book was released on 2010-04-01 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: The safe storage in glass-based materials of both radioactiveand non-radioactive hazardous wastes is covered in a single book,making it unique Provides a comprehensive and timely reference source at thiscritical time in waste management, including an extensive andup-to-date bibliography in all areas outlined to waste conversionand related technologies, both radioactive and non-radioactive Brings together all aspects of waste vitrification, drawscomparisons between the different types of wastes and treatments,and outlines where lessons learnt in the radioactive waste fieldcan be of benefit in the treatment of non-radioactive wastes

Download or read book Ceramics for Environmental and Energy Applications written by Aldo R. Boccaccini and published by John Wiley & Sons. This book was released on 2010-09-21 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is a collection of 17 papers from six symposia held during the 8th Pacific Rim Conference on Ceramic and Glass Technology (PACRIM-8) in Vancouver, British Columbia, Canada, May 31-June 5, 2009. These symposia include: Glasses and Ceramics for Nuclear and Hazardous Waste Treatment Solid Oxide Fuel Cells and Hydrogen Technology Ceramics for Electric Energy Generation, Storage and Distribution Photocatalytic Materials: Reaction, Processing, and Applications Direct Thermal to Electrical Energy Conversion Materials and Applications PACRIM-8 is the eight in a series of international conferences on emerging ceramic technologies that began in 1993. PACRIM-8 was organized and sponsored by The American Ceramic Society and was endorsed by The Australian Ceramic Society, The Ceramic Society of Japan, The Chinese Ceramic Society, and The Korean Ceramic Society. A total of 862 experts, practitioners, and end users from forty-one countries attended PACRIM-8, making it one of the most successful ceramic science and engineering events in recent years.

Download or read book VARIABILITY STUDY TO DETERMINE THE SOLUBILITY OF IMPURITIES IN PLUTONIUM BEARING LANTHANIDE BOROSILICATE GLASS written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study focuses on the development of a compositional envelope that describes the retention of various impurities in lanthanide borosilicate (LaBS) glass for vitrification and immobilization of excess, defense-related plutonium. A limited amount of impurity data for the various plutonium sources is available and projections were made through analysis of the available information. These projections were used to define types and concentrations of impurities in the LaBS glass compositions to be fabricated and tested. Sixty surrogate glass compositions were developed through a statistically designed approach to cover the anticipated ranges of concentrations for several impurity species expected in the plutonium feeds. An additional four glass compositions containing actual plutonium oxide were selected based on their targeted concentrations of metals and anions. The glasses were fabricated and characterized in the laboratory and shielded cells facility to determine the degree of retention of the impurity components, the impact of the impurities on the durability of each glass, and the degree of crystallization that occurred, both upon quenching and slow cooling. Overall, the LaBS glass system appears to be very tolerant of most of the impurity types and concentrations projected in the plutonium waste stream. For the surrogate glasses, the measured CuO, Ga2O3, Na2O, NiO, and Ta2O5 concentrations fell very close to their target values across the ranges of concentrations targeted in this study for each of these components. The measured CaO and PbO concentrations were consistently higher than the targeted values. The measured Cr2O3 and Fe2O3 concentrations were very close to the targets except for the one highest targeted value for each of these components. A solubility limit may have been approached in this glass system for K2O and MgO. The measured Cl−, F−, SeO2 and SO42− concentrations were well below their target values for all of the study glasses. This is likely due to volatilization of these species during melting of the glass batch. Note that the degree of volatilization that occurred in this crucible-scale study may differ from the full-scale melter. The measured HfO2 concentrations were below their target values for all of the surrogate glasses. It is likely that for HfO2, the solubility limit in the glass was exceeded and some of the HfO2 batch material remained in the bottom of the crucibles after pouring the glasses. X-ray diffraction and scanning electron microscopy (SEM) results indicated that some crystalline HfO2 remained in some of the surrogate glasses with the lowest concentration of impurities. No other crystalline phases were identified. The Product Consistency Test (PCT) results showed that all 60 of the surrogate glass compositions tested were very durable, regardless of thermal history, with the highest normalized release for boron being 0.041 g/L. The pH of the leachate solutions was generally lower than that of conventional waste glasses due to the lack of alkali in the LaBS glass, which likely impacted the PCT results. The normalized release rates for the elements measured were generally too small to attempt to correlate the results with the compositions of the test glasses. The Toxicity Characteristic Leaching Procedure results showed that no hazardous metals were leached from the surrogate glasses in any measurable concentration. A plutonium-containing crystalline phase with a cross-shaped morphology was identified via SEM in the glasses fabricated with plutonium oxide. This phase was identified in a previous study of plutonium-bearing LaBS glasses and may provide an opportunity to intentionally crystallize some of the plutonium oxide into a highly insoluble form with an intrinsic neutron absorber. Additional work is necessary to better characterize the influence that this phase has on durability of the glass. The PCT results for the plutonium-containing LaBS glasses with impurities were similar to previous tests conducted on PuO2-containing glasses without impurities added. The highest normalized release for boron was 0.02 g/L, which bounded the highest normalized release for plutonium of 0.01 g/L.

Download or read book EVALUATION OF IMPURITY EXTREMES IN A PLUTONIUM LOADED BOROSILICATE GLASS written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A vitrification technology utilizing a lanthanide borosilicate (LaBS) glass appears to be a viable option for the disposition of excess weapons-useable plutonium that is not suitable for processing into mixed oxide (MOX) fuel. A significant effort to develop a glass formulation and vitrification process to immobilize plutonium was completed in the mid-1990s. The LaBS glass formulation was found to be capable of immobilizing in excess of 10 wt % Pu and to be tolerant of a range of impurities. To confirm the results of previous testing with surrogate Pu feeds containing impurities, four glass compositions were selected for fabrication with actual plutonium oxide and impurities. The four compositions represented extremes in impurity type and concentration. The homogeneity and durability of these four compositions were measured. The homogeneity of the glasses was evaluated using x-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS). The XRD results indicated that the glasses were amorphous with no evidence of crystalline species in the glass. The SEM/EDS analyses did show the presence of some undissolved PuO2 material. The EDS spectra indicated that some of the PuO2 crystals also contained hafnium oxide. The SEM/EDS analyses showed that there were no heterogeneities in the glass due to the feed impurities. The durability of the glasses was measured using the Product Consistency Test (PCT). The PCT results indicated that the durability of Pu impurity glasses was comparable with Pu glasses without impurities and significantly more durable than the Environmental Assessment (EA) glass used as the benchmark for repository disposition of high-level waste (HLW) glasses.

Download or read book Corrosion Testing of a Plutonium loaded Lanthanide Borosilicate Glass Made with Frit B written by W. L. Ebert and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Laboratory tests were conducted with a lanthanide borosilicate (LaBS) glass made with Frit B and added PuO2 (the glass is referred to herein as Pu LaBS-B glass) to measure the dependence of the glass dissolution rate on pH and temperature. These results are compared with the dependencies used in the Defense HLW Glass Degradation Model that was developed to account for HLW glasses in total system performance assessment (TSPA) calculations for the Yucca Mountain repository to determine if that model can also be used to represent the release of radionuclides from disposed Pu LaBS glass by using either the same parameter values that are used for HLW glasses or parameter values specific for Pu LaBS glass. Tests were conducted by immersing monolithic specimens of Pu LaBS-B glass in six solutions that imposed pH values between about pH 3.5 and pH 11, and then measuring the amounts of glass components released into solution. Tests were conducted at 40, 70, and 90 C for 1, 2, 3, 4, and 5 days at low glass-surface-area-to-solution volume ratios. As intended, these test conditions maintained sufficiently dilute solutions that the impacts of solution feedback effects on the dissolution rates were negligible in most tests. The glass dissolution rates were determined from the concentrations of Si and B measured in the test solutions. The dissolution rates determined from the releases of Si and B were consistent with the 'V' shaped pH dependence that is commonly seen for borosilicate glasses and is included in the Defense HLW Glass Degradation Model. The rate equation in that model (using the coefficients determined for HLW glasses) provides values that are higher than the Pu LaBS-B glass dissolution rates that were measured over the range of pH and temperature values that were studied (i.e., an upper bound). Separate coefficients for the rate expression in acidic and alkaline solutions were also determined from the test results to model Pu LaBS-B glass dissolution directly. The releases of Gd, Hf, and Pu from the glass were also measured. The release of Pu was significantly less than Si at all temperatures and pH values (on a normalized basis). More Gd than Pu or Hf was released from the glass in acidic solutions, but more Pu than Gd or Hf was released in alkaline solutions. Almost all of the released Gd remained in solution in tests conducted in Teflon vessels, whereas about half of the released Pu and Hf became fixed to the Teflon. In tests conducted in Type 304L stainless steel vessels, most of the released Gd, Hf, and Pu became fixed to the steel. The aqueous concentrations of Gd, Hf, and Pu decreased from about 2 x 10{sup -5}, 2 x 10{sup -8}, and 1 x 10{sup -7} M in tests solutions near pH 3.7 to about 1 x 10{sup -9}, 8 x 10{sup -10}, and 1 x 10{sup -8} M in test solutions near pH 10.8, respectively, in the 90 C tests in Teflon vessels (the solutions were not filtered prior to analysis). Vapor hydration tests (VHTs) were conducted at 120 and 200 C with Pu LaBS-B glass and SRL 418 glass, which was made to represent the HLW glass that will be used to macro-encapsulate LaBS glass within the waste form. Some VHTs were conducted with specimens of Pu LaBS-B and SRL 418 glasses that were in contact to study the effect of the solution generated as HLW glass dissolves on the corrosion behavior of Pu LaBS-B glass. Other VHTs were conducted in which the glasses were not in contact. The Pu LaBS-B glass is more durable than the HLW glass under these accelerating test conditions, even when the glasses are in contact. The presence of the SRL 418 glass did not promote the dissolution of the Pu LaBS-B glass significantly. However, Gd, Hf, and Pu were detected in alteration phases formed on the Pu LaBS-B glass surface and in (or on) phases formed by SRL 418 glass degradation, such as analcime. This indicates that Gd, Hf, and Pu were transported from the LaBS glass, through the water film formed on the specimens, and to the SRL 418 glass during the test. The disposition of the PuO{sub 2} inclusion phases as the Pu LaBS-B glass dissolved was not determined. They were observed in the glass underlying the alteration layers, but were not detected among the alteration phases.

Download or read book Scientific Basis for Nuclear Waste Management written by and published by . This book was released on 2008 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Homogeneous Glass Processing Region Defined for a Lanthanide Borosilicate Glass Composition for the Mobilization of Plutonium Using Thorium as a Surrogate written by and published by . This book was released on 1996 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: A ternary diagram showing the homogeneous glass processing region of a base frit, rare earth oxide and thorium oxide has been developed for a residence temperature of 1475 C. Thorium oxide was used as a plutonium surrogate. All ThO2 glasses that were processed included a 1:1 mole ratio of Th to Gd. Gadolinium is added to the glass as a neutron absorber. Forty individual glass compositions were melted at 1475 C for 4 to 6 hours with periodic stirring. Two glasses (B-20-25 and B-25-25) were processed with a ThO2 loading of 25 weight percent (oxide) without amorphous phase separation or crystalline species detected by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) or Transmission Electron Microscopy (TEM). These were processed with 55 weight percent frit, 20 weight percent rare earth oxides and 50 percent frit, 25 percent rare earth oxides. Crystalline species that formed outside of the homogeneous glass processing region due to solubility limits or insufficient processing temperature were identified. Amorphous phase separation was detected and examined by TEM at high ThO2 loadings (20 to 30 weight percent oxide). The base frit was able to dissolve up to 65 weight percent rare earth oxides when thorium oxide was not present. Durability testing will be performed on three glasses from three different regions of the homogeneous glass processing region. Product Consistency Test (PCT) results are pending and will be added to this document under a future revision.

Download or read book Development of an ASTM Standard Glass Durability Test the Product Consistency Test PCT for High Level Radioactive Waste Glass written by and published by . This book was released on 1994 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nation's first, and the world's largest, facility to immobilize high-level nuclear waste in durable borosilicate glass has started operation at the Savannah River Site (SRS) in Aiken, South Carolina. The product specifications on the glass wasteform produced in the Defense Waste Processing Facility (DWPF) required extensive characterization of the glass product before actual production began and for continued characterization during production. To aid in this characterization, a glass durability (leach) test was needed that was easily reproducible, could be performed remotely on highly radioactive samples, and could yield results rapidly. Several standard leach tests were examined with a variety of test configurations. Using existing tests as a starting point, the DWPF Product Consistency Test (PCT was developed in which crushed glass samples are exposed to 90 " 2°C deionized water for seven days. Based on extensive testing, including a seven-laboratory round robin and confirmatory testing with radioactive samples, the PCT is very reproducible, yields reliable results rapidly, and can be performed in shielded cell facilities with radioactive samples.

Download or read book Performing a Chemical Durability Test on Radioactive High level Nuclear Waste Glass written by and published by . This book was released on 1990 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Savannah River Site (SRS), currently is storing (approximately)30 million gallons of highly radioactive nuclear wastes. The Defense Waste Processing Facility (DWPF) nearing completion at SRS will incorporate the radionuclides in these wastes into solid borosilicate glass for final disposal in a geologic repository. Because of the variability of the wastes in the tanks, borosilicate glasses of different compositions will be produced by the DWPF during the 20--25 years required to solidify all the wastes at SRS. A chemical durability test, the Product Consistency Test (PCT), has been developed at SRS to measure the consistency of the durability of these glasses. This paper describes the remote and hands-on procedures for performing the PCT on these radioactive glasses. Results will be presented that indicate the good precision of the PCT and indicate some of the chemistry involved in leaching radioactive elements from the glass. 9 refs., 1 fig., 4 tabs.

Download or read book FABRICATION AND CHARACTERIZATION OF BOROSILICATE GLASSES CONTAINING ALPHA RADIONUCLIDES AND SILVER FROM CONVERSION AND MIXED OXIDE FACILITIES PROPOSED FOR RUSSIA written by L. Jardine and published by . This book was released on 2005 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid and solid radioactive wastes are formed during conversion of plutonium metal to oxide and during fabrication of weapons-grade plutonium into mixed-oxide (MOX) fuel. In Russia, these wastes are to be processed for disposition by immobilization in either borosilicate glass or cement matrices depending upon the waste stream-specific radionuclide contents. Vitrification is planned for the liquid high-level waste raffinate stream containing the bulk of the Am-241 produced from Pu-241 decay. Previous work on the Russian MOX Fuel Fabrication Facility (R-MFFF) by the Public Joint Stock Corporation (TVEL) [1] showed that this waste stream may contain significant amounts of silver derived from the electrochemical dissolution of PuO2 using a Ag(II) catalyst. The work reported here further investigated silver solubility limits, which, if exceeded in a production glass melter, allow discrete silver grains to form in the glass and also deposit over time on the bottom of a joule-heated ceramic melter. In melters with immersed electrodes, such as the Russian EP-100 for phosphate glasses or the US Duratek DP-100 type melters for borosilicate glasses that are being considered for use at the Siberian Chemical Combine (SCC) Tomsk site, the undissolved silver could cause a short circuit and an unacceptable production melter failure. The silver solubility limit of 3.85 wt% Ag{sub 2}O in liquid, alpha-bearing wastes determined in this work will guide the production scale use of borosilicate glass compositions, and effectively increase the capacity of the ceramic melters and reduce the total volume of solidified vitrified wastes at SCC Tomsk that require storage prior to geologic disposal.

Download or read book Glass Macrocracking Determination in Prototypic Canisters Containing Lanthanide Borosilicate Glass written by TIMOTHY. JONES and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nuclear Waste Conditioning written by France. Commissariat à l'énergie atomique (CEA) and published by Le Moniteur Editions. This book was released on 2009 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: