Download or read book TIME TEMPERATURE TRANSFORMATION TTT DIAGRAMS FOR FUTURE WASTE COMPOSITIONS written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As a part of the Waste Acceptance Product Specifications (WAPS) for Vitrified High-Level Waste Forms defined by the Department of Energy - Office of Environmental Management, the waste form stability must be determined for each of the projected high-level waste (HLW) types at the Savannah River Site (SRS). Specifically, WAPS 1.4.1 requires the glass transition temperature (T{sub g}) to be defined and time-temperature-transformation (TTT) diagrams to be developed. The T{sub g} of a glass is an indicator of the approximate temperature where the supercooled liquid converts to a solid on cooling or conversely, where the solid begins to behave as a viscoelastic solid on heating. A TTT diagram identifies the crystalline phases that can form as a function of time and temperature for a given waste type or more specifically, the borosilicate glass waste form. In order to assess durability, the Product Consistency Test (PCT) was used and the durability results compared to the Environmental Assessment (EA) glass. The measurement of glass transition temperature and the development of TTT diagrams have already been performed for the seven Defense Waste Processing Facility (DWPF) projected compositions as defined in the Waste Form Compliance Plan (WCP) and in SRNL-STI-2009-00025. Additional phase transformation information exists for other projected compositions, but overall these compositions did not cover composition regions estimated for future waste processing. To develop TTT diagrams for future waste types, the Savannah River National Laboratory (SRNL) fabricated two caches of glass from reagent grade oxides to simulate glass compositions which would be likely processed with and without Al dissolution. These were used for glass transition temperature measurement and TTT diagram development. The glass transition temperatures of both glasses were measured using differential scanning calorimetry (DSC) and were recorded to be 448 C and 452 C. Using the previous TTT diagrams as guidance, subsamples of each glass were isothermally heat treated for 1 to 768 hours at temperatures between 500 C to 1000 C. Each of the heat treated samples, along with quenched and centerline canister cooled (CCC) treated samples, were analyzed using X-ray diffraction (XRD) and the PCT. Maximum crystallization was detected in samples treated at 700 C and 600 C for more than 96 hours in both glasses. Phases crystallized were similar in composition if not the same as those found in the previous TTT studies. Six different crystalline phases were detected, including nepheline, aegirine, lithium silicate, trevorite (spinel based), krinovite, and calcium magnesium iron silicon oxide. Overall, phases were spinel (iron) based, lithium metasilicate, sodium aluminosilicate or alkali transition metal silicate in composition. No new crystalline families were detected. Durability, as measured by the PCT, decreased when lithium silicate or nepheline crystals were present. The conclusions of this study were consistent with previous studies. In order to continue to meet the requirements of the WCP, a simplified strategy is suggested for the generation of future TTT diagrams. Only extremely significant changes in composition resulting from processing strategy changes would require generating more TTT diagrams.

Download or read book TIME TEMPERATURE TRANSFORMATION DIAGRAMS FOR THE SLUDGE BATCH 3 FRIT 418 GLASS SYSTEM written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As a part of the Waste Acceptance Product Specifications (WAPS) for Vitrified High-Level Waste Forms defined by the Department of Energy - Office of Environmental Management, the phase stability must be determined for each of the projected high-level waste (HLW) types at the Savannah River Site (SRS). Specifically, WAPS 1.4.1 requires the glass transition temperature (Tg) to be defined and time-temperature-transformation (TTT) diagrams to be developed. The Tg of a glass is an indicator of the approximate temperature where the supercooled liquid converts to a solid on cooling or conversely, where the solid begins to behave as a viscoelastic solid on heating. A TTT diagram identifies the crystalline phases that can form as a function of time and temperature for a given waste type or more specifically, the borosilicate glass waste form. In order to assess durability, the Product Consistency Test (PCT) was used and the durability results compared to the Environmental Assessment (EA) glass. The measurement of glass transition temperature and the development of TTT diagrams have already been performed for the seven Defense Waste Processing Facility (DWPF) projected compositions as defined in the Waste Form Compliance Plan (WCP). These measurements were performed before DWPF start-up and the results were incorporated in Volume 7 of the Waste Form Qualification Report (WQR). Additional information exists for other projected compositions, but overall these compositions did not consider some of the processing scenarios now envisioned for DWPF to accelerate throughput. Changes in DWPF processing strategy have required this WAPS specification to be revisited to ensure that the resulting phases have been bounded. Frit 418 was primarily used to process HLW Sludge Batch 3 (SB3) at 38% waste loading (WL) through the DWPF. The Savannah River National Laboratory (SRNL) fabricated a cache of glass from reagent grade oxides to simulate the SB3-Frit 418 system at a 38 wt % WL for glass transition temperature measurement and TTT diagram development. The glass transition temperature (Tg) was measured using differential scanning calorimetry (DSC) and was recorded to be 443 ± 3 C. Using the previous TTT diagrams as guidance, subsamples of the glass were isothermally heat treated for 0.5 to 768 hours at temperatures between 400 C to 1100 C. Each of the 56 heat treated samples, along with quenched and centerline canister cooled (CCC) treated samples, were analyzed using Xray diffraction (XRD) and the PCT. Crystallization was detected only in samples treated at 600 C for more than 192 hours, and 700, 800, and 900 C for more than 48 hours. Phases crystallized were similar in composition if not the same as those found in the previous TTT studies. Six different crystalline phases were detected, including nepheline, acmite, lithium silicate, trevorite, krinovite, and albite. Overall, phases were spinel (iron) based, lithium metasilicate, sodium aluminosilicate or sodium transition metal silicate in composition. No new crystalline families were detected. Durability, as measured by the PCT, decreased when lithium silicate or nepheline crystals were present. Only one heat treated sample had a measured PCT response exceeding the benchmark EA glass, which was a sample treated at 600 C for 768 hours. During normal processing at the DWPF these conditions would be highly unlikely to occur, even in an extreme accident scenario. In order to continue to meet the requirements of the WCP, a simplified strategy is suggested for the generation of future TTT diagrams. A strategy has been developed that would require completing two more TTT diagrams for two averaged, future, predicted waste types. By creating diagrams for the resulting glass compositions of encompassing waste types, it will give insight to the crystallization regions possible for those averages. As discussed in the report, 'Initial MAR Assessments to Access the Impact of Al-Dissolution on DWPF Operating Windows' (WSRC-STI 2007-00688), the majority of waste compositions could be grouped into two future flowsheet scenarios, with and without Al-dissolution. Compositions Cluster 2 and Cluster 4 represent these waste projections. MAR assessments were completed on the two clusters and possible frits and windows of operation were selected for each projected waste type. It is recommended that a TTT diagram be developed for the following: (1) Cluster 2 combined with Frit-510 at a 34 wt % WL; and (2) Cluster 4 combined with Frit-418 at a 38 wt % WL. Given the results of the current study showed little change in the types of crystalline phases formed after heat treatment as compared to the TTT diagrams for the WCP glasses, it is unlikely that extreme differences will occur in the TTT diagram for future waste forms, as long as extreme waste stream changes or new frit components are not introduced.

Download or read book Atlas of Time temperature Diagrams for Irons and Steels written by George F. Vander Voort and published by ASM International(OH). This book was released on 1991 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt: Worldwide Participation: Fourteen countries represented.

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 Waste Management and Valorization written by Elena Cristina Rada and published by CRC Press. This book was released on 2017-03-16 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: This title includes a number of Open Access chapters. Edited by a leading researcher in the field, this book provides an overview of waste valorization and includes the editor’s research in addition to other experts and recent and relevant studies on this critical topic. It covers treatment and pretreatment technologies and methodologies, energy recovery from solid wastes, recycling and reuse, additional cutting-edge valorization methodologies. Primarily aimed at researchers and advanced students in biochemical, engineering, and environmental fields, this book should also provide a valuable reference for municipal legislators and industry practitioners.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1992 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 30th Plasmadynamics and Lasers Conference written by and published by . This book was released on 1999 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atlas of Time temperature Diagrams for Irons and Steels written by George F. Vander Voort and published by . This book was released on 1991 with total page 766 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1993-02 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific Basis for Nuclear Waste Management written by and published by . This book was released on 2003 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ceramic Abstracts written by and published by . This book was released on 1998 with total page 1040 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book INIS Atomindex written by and published by . This book was released on 1985 with total page 1364 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1983 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

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 Introduction to Glass Science and Technology written by James E Shelby and published by Royal Society of Chemistry. This book was released on 2015-11-06 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a concise and inexpensive introduction for an undergraduate course in glass science and technology. The level of the book has deliberately been maintained at the introductory level to avoid confusion of the student by inclusion of more advanced material, and is unique in that its text is limited to the amount suitable for a one term course for students in materials science, ceramics or inorganic chemistry. The contents cover the fundamental topics of importance in glass science and technology, including glass formation, crystallization, phase separation and structure of glasses. Additional chapters discuss the most important properties of glasses, including discussion of physical, optical, electrical, chemical and mechanical properties. A final chapter provides an introduction to a number of methods used to form technical glasses, including glass sheet, bottles, insulation fibre, optical fibres and other common commercial products. In addition, the book contains discussion of the effects of phase separation and crystallization on the properties of glasses, which is neglected in other texts. Although intended primarily as a textbook, Introduction to Glass Science and Technology will also be invaluable to the engineer or scientist who desires more knowledge regarding the formation, properties and production of glass.

Download or read book Materials for Nuclear Plants written by Wolfgang Hoffelner and published by Springer Science & Business Media. This book was released on 2012-09-21 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: The clamor for non-carbon dioxide emitting energy production has directly impacted on the development of nuclear energy. As new nuclear plants are built, plans and designs are continually being developed to manage the range of challenging requirement and problems that nuclear plants face especially when managing the greatly increased operating temperatures, irradiation doses and extended design life spans. Materials for Nuclear Plants: From Safe Design to Residual Life Assessments provides a comprehensive treatment of the structural materials for nuclear power plants with emphasis on advanced design concepts. Materials for Nuclear Plants: From Safe Design to Residual Life Assessments approaches structural materials with a systemic approach. Important components and materials currently in use as well as those which can be considered in future designs are detailed, whilst the damage mechanisms responsible for plant ageing are discussed and explained. Methodologies for materials characterization, materials modeling and advanced materials testing will be described including design code considerations and non-destructive evaluation concepts. Including models for simple system dynamic problems and knowledge of current nuclear power plants in operation, Materials for Nuclear Plants: From Safe Design to Residual Life Assessments is ideal for students studying postgraduate courses in Nuclear Engineering. Designers on courses for code development, such as ASME or ISO and nuclear authorities will also find this a useful reference.