Download or read book Investigation of Lead iron phosphate Glass for SRP Waste written by Carol M. Jantzen and published by . This book was released on 1986 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Lead iron phosphate Glass as a High level Waste Form written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The lead-iron-phosphate (Pb-Fe-P) glass developed at Oak Ridge National Laboratory was evaluated for its potential as an improvement over the current reference nuclear waste form, borosilicate (B-Si) glass. The evaluation was conducted as part of the Second Generation HLW Technology Subtask of the Nuclear Waste Treatment Program at Pacific Northwest Laboratory. The purpose of this work was to investigate possible alternatives to B-Si glass as second-generation waste forms. While vitreous Pb-Fe-P glass appears to have substantially better chemical durability than B-Si glass, severe crystallization or devitrification leading to deteriorated chemical durability would result if this glass were poured into large canisters as is the procedure with B-Si glass. Cesium leach rates from this crystallized material are orders of magnitude greater than those from B-Si glass. Therefore, to realize the potential performance advantages of the Pb-Fe-P material in a nuclear waste form, the processing method would have to cool the material rapidly to retain its vitreous structure.
Download or read book Physical and Chemical Characteristics of Lead iron Phosphate Nuclear Waste Glasses written by B. C. Sales and published by . This book was released on 1985 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Iron Phosphate Glasses as a Potential Nuclear Waste Disposal Medium written by Milissa Gay Mesko and published by . This book was released on 1995 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Iron Phosphate Glass as an Alternative Waste Form for Hanford LAW written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Although the current baseline Hanford flowsheet for immobilizing low-activity waste (LAW) assumes borosilicate-based glass, opportunities exist to improve or change this baseline to reduce the current schedule and cost requirements of accomplishing the mission of site cleanup. Development of an alternative glass-forming system can lead to this goal of cost and schedule reduction through enhanced waste loading and higher plant throughput. The purpose of this project is to investigate the iron-phosphate glass system as an alternative for immobilizing Hanford LAW. Previous studies on the iron phosphate glass systems and their potential advantages for immobilizing Hanford LAW have been reviewed and technical uncertainties and data required before implementing this technology have been presented. A team of researchers and engineers from the MO-SCI Corporation, the Pacific Northwest National Laboratory, the Savannah River Technology Center, and the University of Missouri at Rolla has performed a series of tests to address some of the open questions about the potential use of iron phosphate glass for immobilizing Hanford LAW. The results of this team effort are summarized along with recommendations regarding the further laboratory study needs. Additional longer-term testing requirements for implementing the iron phosphate glass-based immobilization process at Hanford are also presented.
Download or read book An Investigation of Iron Phosphate Glasses written by Xiangyu Fang and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The effect of melting history on the iron redox equilibrium, structure, crystallization and properties of a binary iron phosphate glass with a 40Fe2O3-60P2O5 mol%, batch composition were investigated. The structure and properties of single and mixed alkali iron phosphate glasses were also studied. Mössbauer, Raman and infrared spectroscopy were used to determine the changes in the concentration of iron ions and phosphate units in the structure. Differential thermal analysis, X-ray diffraction and thermogravimetric analysis were used to investigate crystallization. Density, molar volume, thermal expansion, dc electrical conductivity and dielectric constant and loss tangent were measured. The heat capacity and glass transition behavior of the glasses was also measured by the differential scanning calorimeter method. The effect of the melting temperature is stronger than the melting time on the concentration of Fe2 ions in iron phosphate glasses. The pyrophosphate network in iron phosphate glasses and their general properties do not change either with melting temperature and time or with adding up to 20 mol% of single and mixed alkali oxides. The dissolution rate (in deionized water) of these glasses is generally very low (~10−9 g/cm2/min) and nearly independent of the relative concentration of Fe2 or Fe3+ ions. The dissolution rate of the iron phosphate glasses containing 20 mol% of single or mixed alkali oxide can be comparable to that of window glass. There is no mixed alkali effect in the iron phosphate glasses. The crystallization tendency indicates that the glass structure becomes closer to that of crystalline Fe3(P2O-- )2 with increasing concentration of Fe2+ ions in the glass. The large fragility parameters indicates that the iron phosphate glasses belong in the category of the fragile glass-forming liquids"--Abstract, leaf v
Download or read book Iron Phosphate Glass for the Vitrification of INEEL Sodium Bearing Waste and Hanford Low Activity Waste written by Robert Douglas Leerssen and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The current study investigates the feasibility of using iron phosphate glass for the immobilization of nuclear wastes that have limited solubility in the current borosilicate glass used for vitrification. These wastes contain elements such as sulfur and phosphorus, which have proven problematic (causing phase separation at>1 wt%) for vitrification in borosilicate glasses, as well as having a high soda content (50-75 wt%) which also limits wasteloading"--Abstract, p. iv
Download or read book A Review of Iron Phosphate Glasses and Recommendations for Vitrifying Hanford Waste written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report contains a comprehensive review of the research conducted, world-wide, on iron phosphate glass over the past ~30 years. Special attention is devoted to those iron phosphate glass compositions which have been formulated for the purpose of vitrifying numerous types of nuclear waste, with special emphasis on the wastes stored in the underground tanks at Hanford WA. Data for the structural, chemical, and physical properties of iron phosphate waste forms are reviewed for the purpose of understanding their (a) outstanding chemical durability which meets all current DOE requirements, (b) high waste loadings which can exceed 40 wt% (up to 75 wt%) for several Hanford wastes, (c) low melting temperatures, can be as low as 900°C for certain wastes, and (d) high tolerance for "problem" waste components such as sulfates, halides, and heavy metals (chromium, actinides, noble metals, etc.). Several recommendations are given for actions that are necessary to smoothly integrate iron phosphate glass technology into the present waste treatment plans and vitrification facilities at Hanford.
Download or read book Iron Phosphate Glass Containing Hanford Waste Simulant written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Resolution of the nation's high-level tank waste legacy requires the design, construction, and operation of large and technically complex one-of-a-kind processing waste treatment and vitrification facilities. While the ultimate limits for waste loading and melter efficiency have yet to be defined or realized, significant reductions in glass volumes for disposal and mission life may be possible with advancements in melter technologies and/or glass formulations. This test report describes the experimental results from a small-scale test using the research-scale melter (RSM) at Pacific Northwest National Laboratory (PNNL) to demonstrate the viability of iron-phosphate-based glass with a selected waste composition that is high in sulfate (4.37 wt% SO3). The primary objective of the test was to develop data to support a cost-benefit analysis related to the implementation of phosphate-based glasses for Hanford low-activity waste (LAW) and/or other high-level waste streams within the U.S. Department of Energy complex. The testing was performed by PNNL and supported by Idaho National Laboratory, Savannah River National Laboratory, Missouri University of Science and Technology, and Mo-Sci Corporation.
Download or read book Immobilization of Radioactive Materials in Iron Phosphate Glass written by Melissa G. Mesko and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The current study investigates the feasibility of using iron phosphate glass for the immobilization of radioactive wastes considered incompatible with borosilicate glass. Wastes may be incompatible with borosilicate glass due to high phosphorus content (Hanford tank sludges), the presence of halides (CsCl and SrF2 capsules), or large amounts of uranium (SNF). Between 20 and 60 wt% Hanford tank sludge was vitrified with an iron phosphate glass at ̲1200°C in 1 hour. The chemical durability of iron phosphate glassy wasteforms was as good as, or better than a reference borosilicate glass (10−9 g/cm2/min) in distilled water at 90°C. Adding 7 wt% CaF2 to the batch decreased the melt temperature by 50°C and the melt viscosity without affecting the chemical durability of the glassy wasteform. Iron phosphate glasses made with CsCl and SrF2 were prepared at̲ 950°C in 2 hours. Chemical analysis indicates neither Cs or Sr are volatilized from the batch. The chemical durability of glasses made with CsCl or SrF2 was as good as, or better than a reference borosilicate glass (10−9 g/cm2/min) in distilled water at 90°C. Glasses made with both CsCl and SrF2 had a better chemical durability from pH 2 to pH 12. Iron phosphate glasses containing 15 wt% SNF were produced by melting at 1150°C for 2 hours. Adding a small amount (as little as 2.5 wt%) of Na2O decreased melt viscosity and reduced devitrification tendency. The chemical durability of all but one of the glassy wasteforms containing SNF was as good as, or better than a borosilicate reference glass (10−9 g/cm2/min) in distilled water at 90°C. The chemical durability of all of the iron phosphate compositions in the current study increased as the amount of iron and aluminum in the batch increased. The durability of the iron phosphate glasses was further improved by the formation of an iron-rich surface layer and the buffering action which occurs as a phosphate glass reacts with water"--Abstract, leaf iv
Download or read book Lieder f r die Schw bische Volksjugend written by and published by . This book was released on 1946 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Iron Phosphate Glasses written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: A high priority has been given to investigating the vitrification of three specific nuclear wastes in iron phosphate glasses (IPG). These wastes, which were recommended by the Tank Focus Area (TFA) group of Hanford, are poorly suited for vitrification in the currently DOE-approved borosilicate (BS) glasses. They include (1) a sodium bearing waste (SBW) at INEEL, (2) a high chrome waste (HCW) at Hanford, and (3) a high sodium/sulfate waste (HSSW), also known as low activity waste (LAW) at Hanford. A simulated composition for each waste, which was simplified by neglecting components present in quantities
Download or read book An Alternative Host Matrix Based on Iron Phosphate Glasses for the Vitrification of Specialized Nuclear Waste Forms written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Certain high level wastes (HLW) in the U.S. contain components such as phosphates, heavy metals, and halides which make them poorly suited for disposal in borosilicate glasses. Iron phosphate glasses appear to be a technically feasible alternative to borosilicate glasses for vitrifying these HLWs. The iron phosphate glasses mentioned above and their nuclear wasteforms are relatively new, so little is known about their atomic structure, redox equilibria, structure-property relationships, and crystallization products and characteristics. The objective of this research is to gain such information for the binary iron-phosphate glasses as well as iron phosphate wasteforms so that a comprehensive scientific assessment can be made of their usefulness in nuclear waste disposal.
Download or read book An Alternative Host Matrix Based on Iron Phosphate Glasses for the Vitrification of Specialized Nuclear Waste Forms 1998 Annual Progress Report written by and published by . This book was released on 1998 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Certain high level wastes (HLW) in the US contain components such as phosphates, heavy metals, and halides which make them poorly suited for disposal in borosilicate glasses. Iron phosphate glasses appear to be a technically feasible alternative to borosilicate glasses for vitrifying these HLWs. The iron phosphate glasses mentioned above and their nuclear wasteforms are relatively new, so little is known about their atomic structure, redox equilibria, structure-property relationships, and crystallization products and characteristics. The objective of this research is to gain such information for the binary iron-phosphate glasses as well as iron phosphate wasteforms so that a comprehensive scientific assessment can be made of their usefulness in nuclear waste disposal. This report summarizes the work undertaken and completed in the first 20 months of a three year project. Approximately 250 samples, binary iron phosphate glasses and iron phosphate glasses containing one or two common nuclear waste components such as UO2, Na2O, Bi2O3, Cs2O, SrO, and MoO3, have been prepared. Weight loss has been used to measure the chemical durability and the redox equilibria between Fe(II) and Fe(III) has been investigated using Moessbauer spectroscopy. The atomic structure has been investigated using a variety of techniques including Mossbauer, Raman, X-ray absorption (XAS), and X-ray photoelectron (XPS) spectroscopies and neutron/high energy X-ray scattering. Glass forming and crystallization characteristics have been investigated using differential thermal analysis (DTA). In addition, information necessary for glass manufacturing such as suitable refractories and Joule heating parameters also have been obtained.
Download or read book Novel Lead iron Phosphate Glass written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The invention described and claimed in the specification relates to the discovery that effective addition of Fe.sub. 2 O.sub. 3 to a lead phosphate glass results in a glass having enhanced chemical durability and physical stability, and consists essentially of the glass resulting from melting a mixture consisting essentially of, in weight percent, 40-66 percent PbO, 30-55 percent P.sub. 2 O.sub. 5 and an effective concentration up to 12 percent Fe.sub. 2 O.sub. 3.
Download or read book Iron Phosphate Glass as Potential Waste Matrix for High Level Radioactive Waste written by K. Suzuki and published by . This book was released on 2003 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently, Iron Phosphate Glass (IPG) is investigated as the alternative final waste form for High-Level Radioactive Waste (HLW) in U.S. This study is aimed to investigate feasibility of IPG to HLW arising from commercial reprocessing in Japan. In order to evaluate favorable preparation conditions, maximum waste loading and property of IPG, the melting tests were carried. From the results of melting tests, the favorable preparation conditions was with matrix of Fe/P 0.43 (mole ratio in products) and melting at 1200{sup o} for 4h. The products of 10-20mass% waste loading of simulated HLW were glassy and had no crystal peaks, however the product of 30mass% waste loading showed some crystal peaks by XRD analysis. IPG and Borosilicate glass (BG) had about the same thermal properties. As a result, IPG had enough potential for high waste loading and the extremely good chemical durability for consideration as a waste form for Japanese HLW.
Download or read book The Effects of Uranium Oxide High level Waste on the Structure of Iron Phosphate Glasses written by and published by . This book was released on 1998 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because of their unusually good chemical durability, iron phosphate glasses are a natural candidate for a nuclear waste disposal glass. We have studied the effects of UO2 high-level waste on the structure of iron phosphate glasses with both neutron and high-energy x-ray diffraction using the GLAD instrument of the Intense Pulsed Neutron Source and the 1-BM bending magnet beamline of the Advanced Photon Source, respectively. The results of neutron scattering, which is mostly sensitive to correlations involving light atoms i.e. O-O, Fe-O and P-O, suggest the main structural features of the base glass are largely unaffected by the addition of UO2. The nearest-neighbor P-O, Fe-O and O-O peaks remain at the same position in real space and their intensities scale approximately with concentration. These findings are consistent with the earlier results of Raman scattering and EXAFS on the Fe-K edge wherein both cases the spectra remain similar to the base glass. High-energy x-ray scattering which is sensitive to correlations involving the heavier atoms and thus complements the neutron measurements, is also consistent with uranium occupying interstitial sites in the relatively undisturbed base glass structure. However, important questions remain as to the precise local structure and oxidation state of uranium in these glasses.
