Download or read book Defense HLW Glass Degradation Model written by D. Strachan and published by . This book was released on 2004 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this report is to document the development of a model for calculating the release rate for radionuclides and other key elements from high-level radioactive waste (HLW) glasses under exposure conditions relevant to the performance of the repository. Several glass compositions are planned for the repository, some of which have yet to be identified (i.e., glasses from Hanford and Idaho National Engineering and Environmental Laboratory). The mechanism for glass dissolution is the same for these glasses and the glasses yet to be developed for the disposal of DOE wastes. All of these glasses will be of a quality consistent with the glasses used to develop this report.
Download or read book Defense High Level Waste Glass Degradation written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this Analysis/Model Report (AMR) is to document the analyses that were done to develop models for radionuclide release from high-level waste (HLW) glass dissolution that can be integrated into performance assessment (PA) calculations conducted to support site recommendation and license application for the Yucca Mountain site. This report was developed in accordance with the ''Technical Work Plan for Waste Form Degradation Process Model Report for SR'' (CRWMS M & O 2000a). It specifically addresses the item, ''Defense High Level Waste Glass Degradation'', of the product technical work plan. The AP-3.15Q Attachment 1 screening criteria determines the importance for its intended use of the HLW glass model derived herein to be in the category ''Other Factors for the Postclosure Safety Case-Waste Form Performance'', and thus indicates that this factor does not contribute significantly to the postclosure safety strategy. Because the release of radionuclides from the glass will depend on the prior dissolution of the glass, the dissolution rate of the glass imposes an upper bound on the radionuclide release rate. The approach taken to provide a bound for the radionuclide release is to develop models that can be used to calculate the dissolution rate of waste glass when contacted by water in the disposal site. The release rate of a particular radionuclide can then be calculated by multiplying the glass dissolution rate by the mass fraction of that radionuclide in the glass and by the surface area of glass contacted by water. The scope includes consideration of the three modes by which water may contact waste glass in the disposal system: contact by humid air, dripping water, and immersion. The models for glass dissolution under these contact modes are all based on the rate expression for aqueous dissolution of borosilicate glasses. The mechanism and rate expression for aqueous dissolution are adequately understood; the analyses in this AMR were conducted to provide models and parameter values that can be used to calculate the dissolution rates for the different modes of water contact. The analyses were conducted to identify key aspects of the mechanistic model for glass dissolution to be included in the abstracted models used for PA calculations, evaluate how the models can be used to calculate bounding values of the glass dissolution rates under anticipated water contact modes in the disposal. system, and determine model parameter values for the range of potential waste glass compositions and anticipated environmental conditions. The analysis of a bounding rate also considered the effects of the buildup of glass corrosion products in the solution contacting the glass and potential effects of alteration phase formation. Note that application of the models and model parameter values is constrained to the anticipated range of HLW glass compositions and environmental conditions. The effects of processes inherent to exposure to humid air and dripping water were not modeled explicitly. Instead, the impacts of these processes on the degradation rate were taken into account by using empirically measured parameter values. These include the rates at which water sorbs onto the glass, drips onto the glass, and drips off of the glass. The dissolution rates of glasses that were exposed to humid air and dripping water measured in laboratory tests are used to estimate model parameter values for contact by humid air and dripping water in the disposal system.
Download or read book Comprehensive Nuclear Materials written by Todd R Allen and published by Elsevier. This book was released on 2011-05-12 with total page 3552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Nuclear Materials, Five Volume Set discusses the major classes of materials suitable for usage in nuclear fission, fusion reactors and high power accelerators, and for diverse functions in fuels, cladding, moderator and control materials, structural, functional, and waste materials. The work addresses the full panorama of contemporary international research in nuclear materials, from Actinides to Zirconium alloys, from the worlds' leading scientists and engineers. Critically reviews the major classes and functions of materials, supporting the selection, assessment, validation and engineering of materials in extreme nuclear environment Fully integrated with F-elements.net, a proprietary database containing useful cross-referenced property data on the lanthanides and actinides Details contemporary developments in numerical simulation, modelling, experimentation, and computational analysis, for effective implementation in labs and plants
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 Final Environmental Impact Statement for a Geologic Repository for the Disposal of Spent Nuclear Fuel and High level Radioactive Waste at Yucca Mountain Nye County Nevada written by and published by . This book was released on 2002 with total page 1204 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this environmental impact statement (EIS) is to provide information on potential environmental impacts that could result from a Proposed Action to construct, operate and monitor, and eventually close a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste at the Yucca Mountain site in Nye County, Nevada. The EIS also provides information on potential environmental impacts from an alternative referred to as the No-Action Alternative, under which there would be no development of a geologic repository at Yucca Mountain.
Download or read book DEVELOPMENT OF GLASS MATRICES FOR HLW RADIOACTIVE WASTES written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. Most of the nations that have generated HLW are immobilizing in either borosilicate glass or phosphate glass. One of the primary reasons that glass has become the most widely used immobilization media is the relative simplicity of the vitrification process, e.g. melt waste plus glass forming frit additives and cast. A second reason that glass has become widely used for HLW is that the short range order (SRO) and medium range order (MRO) found in glass atomistically bonds the radionuclides and governs the melt properties such as viscosity, resistivity, sulphate solubility. The molecular structure of glass controls contaminant/radionuclide release by establishing the distribution of ion exchange sites, hydrolysis sites, and the access of water to those sites. The molecular structure is flexible and hence accounts for the flexibility of glass formulations to waste variability. Nuclear waste glasses melt between 1050-1150 C which minimizes the volatility of radioactive components such as Tc99, Cs137, and I129. Nuclear waste glasses have good long term stability including irradiation resistance. Process control models based on the molecular structure of glass have been mechanistically derived and have been demonstrated to be accurate enough to control the world's largest HLW Joule heated ceramic melter in the US since 1996 at 95% confidence.
Download or read book Scientific Basis for Nuclear Waste Management written by and published by . This book was released on 2004 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book System Analyses on Advanced Nuclear Fuel Cycle and Waste Management written by Myeongguk Cheon and published by . This book was released on 2005 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radioactive Waste Management and Contaminated Site Clean Up written by William E Lee and published by Elsevier. This book was released on 2013-10-31 with total page 925 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radioactive waste management and contaminated site clean-up reviews radioactive waste management processes, technologies, and international experiences. Part one explores the fundamentals of radioactive waste including sources, characterisation, and processing strategies. International safety standards, risk assessment of radioactive wastes and remediation of contaminated sites and irradiated nuclear fuel management are also reviewed. Part two highlights the current international situation across Africa, Asia, Europe, and North America. The experience in Japan, with a specific chapter on Fukushima, is also covered. Finally, part three explores the clean-up of sites contaminated by weapons programmes including the USA and former USSR. Radioactive waste management and contaminated site clean-up is a comprehensive resource for professionals, researchers, scientists and academics in radioactive waste management, governmental and other regulatory bodies and the nuclear power industry. Explores the fundamentals of radioactive waste including sources, characterisation, and processing strategies Reviews international safety standards, risk assessment of radioactive wastes and remediation of contaminated sites and irradiated nuclear fuel management Highlights the current international situation across Africa, Asia, Europe, and North America specifically including a chapter on the experience in Fukushima, Japan
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 Package Performance Evaluation written by D. Lester and published by . This book was released on 1983 with total page 178 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 HIGH LEVEL WASTE HLW VITRIFICATION EXPERIENCE IN THE US written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. At the Savannah River Site (SRS) actual HLW tank waste has successfully been processed to stringent product and process constraints without any rework into a stable borosilicate glass waste since 1996. A unique 'feed forward' statistical process control (SPC) has been used rather than statistical quality control (SQC). In SPC, the feed composition to the melter is controlled prior to vitrification. In SQC, the glass product is sampled after it is vitrified. Individual glass property models form the basis for the 'feed forward' SPC. The property models transform constraints on the melt and glass properties into constraints on the feed composition. The property models are mechanistic and depend on glass bonding/structure, thermodynamics, quasicrystalline melt species, and/or electron transfers. The mechanistic models have been validated over composition regions well outside of the regions for which they were developed because they are mechanistic. Mechanistic models allow accurate extension to radioactive and hazardous waste melts well outside the composition boundaries for which they were developed.
Download or read book Department of Defense Authorization for Appropriations for Fiscal Year 1994 and the Future Years Defense Program Nuclear deterrence arms control and defense intelligence written by United States. Congress. Senate. Committee on Armed Services and published by . This book was released on 1999 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Wastes written by National Research Council and published by National Academies Press. This book was released on 1996-02-23 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: Disposal of radioactive waste from nuclear weapons production and power generation has caused public outcry and political consternation. Nuclear Wastes presents a critical review of some waste management and disposal alternatives to the current national policy of direct disposal of light water reactor spent fuel. The book offers clearcut conclusions for what the nation should do today and what solutions should be explored for tomorrow. The committee examines the currently used "once-through" fuel cycle versus different alternatives of separations and transmutation technology systems, by which hazardous radionuclides are converted to nuclides that are either stable or radioactive with short half-lives. The volume provides detailed findings and conclusions about the status and feasibility of plutonium extraction and more advanced separations technologies, as well as three principal transmutation concepts for commercial reactor spent fuel. The book discusses nuclear proliferation; the U.S. nuclear regulatory structure; issues of health, safety and transportation; the proposed sale of electrical energy as a means of paying for the transmutation system; and other key issues.
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 Glass as a Matrix for SRP High level Defense Waste written by and published by . This book was released on 19?? with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
