Vitrification of High Sulfate Wastes
Vitrification of High Sulfate Wastes

Author:

Publisher:

Published: 1994

Total Pages: 5

ISBN-13:

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The US Department of Energy (DOE) through the Mixed Waste Integrated Program (MWIP) is investigating the application of vitrification technology to mixed wastes within the DOE system This work involves identifying waste streams, laboratory testing to identify glass formulations and characterize the vitrified product, and demonstration testing with the actual waste in a pilot-scale system. Part of this program is investigating process limits for various waste components, specifically those components that typically create problems for the application of vitrification, such as sulfate, chloride, and phosphate. This work describes results from vitrification testing for a high-sulfate waste, the 183-H Solar Evaporation Basin waste at Hanford. A low melting phosphate glass formulation has been developed for a waste stream high in sodium and sulfate. At melt temperatures in the range of 1,000 C to 1,200 C, sulfate in the waste is decomposed to gaseous oxides and driven off during melting, while the remainder of the oxides stay in the melt. Decomposition of the sulfates eliminates the processing problems typically encountered in vitrification of sulfate-containing wastes, resulting in separation of the sulfate from the remainder of the waste and allowing the sulfate to be collected in the off-gas system and treated as a secondary waste stream. Both the vitreous product and intentionally devitrified samples are durable when compared to reference glasses by TCLP and DI water leach tests. Simple, short tests to evaluate the compatibility of the glasses with potential melter materials found minimal corrosion with most materials.

RETENTION OF SULFATE IN HIGH LEVEL RADIOACTIVE WASTE GLASS.
RETENTION OF SULFATE IN HIGH LEVEL RADIOACTIVE WASTE GLASS.

Author:

Publisher:

Published: 2010

Total Pages:

ISBN-13:

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High level radioactive wastes are being vitrified at the Savannah River Site for long term disposal. Many of the wastes contain sulfate at concentrations that can be difficult to retain in borosilicate glass. This study involves efforts to optimize the composition of a glass frit for combination with the waste to improve sulfate retention while meeting other process and product performance constraints. The fabrication and characterization of several series of simulated waste glasses are described. The experiments are detailed chronologically, to provide insight into part of the engineering studies used in developing frit compositions for an operating high level waste vitrification facility. The results lead to the recommendation of a specific frit composition and a concentration limit for sulfate in the glass for the next batch of sludge to be processed at Savannah River.

Laboratory-scale Vitrification and Leaching of Hanford High-level Waste for the Purpose of Simulant and Glass Property Models Validation
Laboratory-scale Vitrification and Leaching of Hanford High-level Waste for the Purpose of Simulant and Glass Property Models Validation

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Publisher:

Published: 1993

Total Pages: 12

ISBN-13:

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The Hanford Waste Vitrification Plant (HWVP) is being built to process the high-level and TRU waste into canistered glass logs for disposal in a national repository. Testing programs have been established within the Project to verify process technology using simulated waste. A parallel testing program with actual radioactive waste is being performed to confirm the validity of using simulates and glass property models for waste form qualification and process testing. The first feed type to be processed by and the first to be tested on a laboratory-scale is pretreated neutralized current acid waste (NCAW). The NCAW is a neutralized high-level waste stream generated from the reprocessing of irradiated nuclear fuel in the Plutonium and Uranium Extraction (PUREX) Plant at Hanford. As part of the fuel reprocessing, the high-level waste generated in PUREX was denitrated with sugar to form current acid waste (CAW). Sodium hydroxide and sodium nitrite were added to the CAW to minimize corrosion in the tanks, thus yielding neutralized CAW. The NCAW contains small amounts of plutonium, fission products from the irradiated fuel, stainless steel corrosion products, and iron and sulfate from the ferrous sulfamate reductant used in the PUREX process. This paper will discuss the results and status of the laboratory-scale radioactive testing.

Vitrification Studies for Savannah River Plant Radioactive Wastes
Vitrification Studies for Savannah River Plant Radioactive Wastes

Author:

Publisher:

Published: 1977

Total Pages:

ISBN-13:

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Borosilicate glass is being studied as a possible matrix for solidification of Savannah River Plant radioactive waste. Glass compositions, radiation and thermal stabilities, radionuclide volatility, sulfate solubility, and glass dissolution were studied. Up to 40 wt. percent simulated or radioactive wastes have been vitrified at 1150°C.

Research Needs for High-Level Waste Stored in Tanks and Bins at U.S. Department of Energy Sites
Research Needs for High-Level Waste Stored in Tanks and Bins at U.S. Department of Energy Sites

Author: National Research Council

Publisher: National Academies Press

Published: 2001-10-05

Total Pages: 146

ISBN-13: 0309075653

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The United States Department of Energy (DOE) has approximately 400 million liters (100 million gallons) of liquid high-level waste (HLW) stored in underground tanks and approximately 4,000 cubic meters of solid HLW stored in bins. The current DOE estimate of the cost of converting these liquid and solid wastes into stable forms for shipment to a geological repository exceeds $50 billion to be spent over several decades (DOE, 2000). The Committee on Long-Term Research Needs for Radioactive High-Level Waste at Department of Energy Sites was appointed by the National Research Council (NRC) to advise the Environmental Management Science Program (EMSP) on a long-term research agenda addressing the above problems related to HLW stored in tanks and bins at DOE sites.

Energy, Waste and the Environment
Energy, Waste and the Environment

Author: R. Gieré

Publisher: Geological Society of London

Published: 2004

Total Pages: 694

ISBN-13: 9781862391673

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This book provides incentives for further development of sustainable fuel cycles through a novel and interdisciplinary approach to an Earth science-related topic. The main focus is on geochemical concepts in immobilizing, isolating or neutralizing waste derived from energy production and consumption. The book also addresses the issue of using some types of energy-derived waste as alternative raw materials. Moreover, it highlights research on how certain wastes can be used for energy production, an increasingly important aspect of modern integrated waste management strategies. The main objectives are to: (a) identify the most serious environmental problems related to various types of power generation and associated waste accumulation; (b) present strategies, based on natural analogue materials, for the immobilization of toxic and radioactive waste components through mineralogical barriers; (c) discuss modern procedures for reuse of waste or certain waste components; and (d) review the importance of geochemical modelling in describing and predicting the interaction between waste and the environment.