Testing of Low Temperature Stabilization Alternatives for Salt-containing Mixed Wastes -- Approach and Results to Date
Testing of Low Temperature Stabilization Alternatives for Salt-containing Mixed Wastes -- Approach and Results to Date

Author:

Publisher:

Published: 1998

Total Pages: 8

ISBN-13:

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Through its annual process of identifying technology deficiencies associated with waste treatment, the Department of Energys̀ (DOE) Mixed Waste Focus Area (MWFA) determined that the former DOE weapons complex lacks efficient mixed waste stabilization technologies for salt containing wastes. The current method used to stabilize salt waste for compliant disposal is grouting with Portland cement. This method is inefficient since the highly soluble and reactive chloride, nitrate, and sulfate salts interfere with the hydration and setting processes associated with grouting. The following five alternative salt waste stabilization technologies were selected for MWFA development funding in FY97 and FY98: (1) Phosphate Bonded Ceramics, (2) Sol-gel, (3) Polysiloxane, (4) Polyester Resin, and (5) Enhanced Concrete. Comparable evaluations were planned for the stabilization development efforts. Under these evaluations each technology stabilized the same type of salt waste surrogates as specified by the MWFA. Final waste form performance data such as compressive strength, waste loading, and leachability can then be equally compared to the requirements originally specified. In addition to the selected test results provided in this paper, the performance of each alternative stabilization technology, will be documented in formal MWFA Innovative Technology Summary Reports (ITSRs).

The Office of Environmental Management Technical Reports: A Bibliography
The Office of Environmental Management Technical Reports: A Bibliography

Author:

Publisher: DIANE Publishing

Published: 2001

Total Pages: 245

ISBN-13: 1428918744

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The Office of Environmental Management's (EM) technical reports bibliography is an annual publication that contains information on scientific and technical reports sponsored by the Office of Environmental Management added to the Energy Science and Technology Database from July 1, 1994 through June 30, 1995. This information is divided into the following categories: Focus Areas, Cross-Cutting Programs, and Support Programs. In addition, a category for general information is included. EM's Office of Science and Technology sponsors this bibliography.

Environmental Issues and Waste Management Technologies in the Ceramic and Nuclear Industries IX
Environmental Issues and Waste Management Technologies in the Ceramic and Nuclear Industries IX

Author: John D. Vienna

Publisher: John Wiley & Sons

Published: 2012-04-05

Total Pages: 384

ISBN-13: 1118407024

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In today's world of increasingly stringent environmental regulations, it is critical to identify and adequately address environmental issues in the ceramic industry to ensure success. In addition, ceramics and glasses play a critical role in the nuclear industry. Nuclear fuels and waste forms for low-level and high-level radioactive, mixed, and hazardous wastes are primarily either ceramic of glass. Effective and responsible environmental stewardship is becoming increasingly more important in the world. These proceedings detail the results of the ongoing effort in these areas. Proceedings of the symposium held at the 105th Annual Meeting of The American Ceramic Society, April 27-30, in Nashville, Tennessee; Ceramic Transactions, Volume 155.

Stability High Salt Content Waste Using Sol Gel Process. Mixed Waste Focus Area. OST Reference Number 0236
Stability High Salt Content Waste Using Sol Gel Process. Mixed Waste Focus Area. OST Reference Number 0236

Author:

Publisher:

Published: 1999

Total Pages: 27

ISBN-13:

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Mixed waste sludges, soils, and homogeneous solids containing high levels of salt (~ greater than 15% by weight) have proven to be difficult to stabilize due to the soluble nature of the salts. The current stabilization technique for high salt waste, grouting with Portland cement, is limited to low waste loadings. The presence of salts interfere with the hydration and curing of the cement, cause waste form deteriorating mineral expansions, or result in an undesirable separate phase altogether. Improved technologies for the stabilization of salt waste must be able to accommodate higher salt loadings, while maintaining structural integrity, chemical durability, and leach resistance. In a joint collaboration supported by the Department of Energy's (DOE's) Mixed Waste Focus Area (MWFA), the Pacific Northwest National Laboratory (PNNL) and the Arizona Materials Laboratory (AML) at the University of Arizona have developed a sol-gel (wet-chemical) based, low-temperature-processing route for the stabilization of salt-containing mixed wastes. By blending and reacting liquid precursors at room temperature with salt waste, strong, impermeable "polyceram" matrices have been formed that encapsulate the environmentally hazardous waste components. As depicted by Figure 1, polycerams are hybrid organic/inorganic materials with unique properties derived from the chemical combination of polymer (organic) and ceramic (inorganic) components. For this application, the stabilizing polyceram matrices contain polybutadiene-based polymer components and silicon dioxide (SiO2) as the inorganic component. Polybutadiene (PBD) is a strong, tough, waterresistant plastic and its use in the polyceram promotes these same characteristics in the waste form. The PBD polymer component is modified to increase its reactivity with the SiO2 precursor during sol-gel processing. When combined, the polymer and SiO2 precursors react, gel, solidify, and encapsulate the salt waste components. The toxicity characterization leaching procedure (TCLP), Compressive Strength (ASTM C 39-94) and leachability tests (ANSI/ANS 16.1) confirm the efficacy of this approach, indicating that polyceram-based salt waste forms have the potential to provide end users with unique capabilities for disposing of salt-containing mixed wastes.

Alternatives for High-Level Waste Salt Processing at the Savannah River Site
Alternatives for High-Level Waste Salt Processing at the Savannah River Site

Author: National Research Council

Publisher: National Academies Press

Published: 2000-10-30

Total Pages: 154

ISBN-13: 030917158X

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The Second World War introduced the world to nuclear weapons and their consequences. Behind the scene of these nuclear weapons and an aspect of their consequences is radioactive waste. Radioactive waste has varying degrees of harmfulness and poses a problem when it comes to storage and disposal. Radioactive waste is usually kept below ground in varying containers, which depend on how radioactive the waste it. High-level radioactive waste (HLW) can be stored in underground carbon-steel tanks. However, radioactive waste must also be further immobilized to ensure our safety. There are several sites in the United States where high-level radioactive waste (HLW) are stored; including the Savannah River Site (SRS), established in 1950 to produce plutonium and tritium isotopes for defense purposes. In order to further immobilize the radioactive waste at this site an in-tank precipitation (ITP) process is utilized. Through this method, the sludge portion of the tank wastes is being removed and immobilized in borosilicate glass for eventual disposal in a geological repository. As a result, a highly alkaline salt, present in both liquid and solid forms, is produced. The salt contains cesium, strontium, actinides such as plutonium and neptunium, and other radionuclides. But is this the best method? The National Research Council (NRC) has empanelled a committee, at the request of the U.S. Department of Energy (DOE), to provide an independent technical review of alternatives to the discontinued in-tank precipitation (ITP) process for treating the HLW stored in tanks at the SRS. Alternatives for High-Level Waste Salt Processing at the Savannah RIver Site summarizes the finding of the committee which sought to answer 4 questions including: "Was an appropriately comprehensive set of cesium partitioning alternatives identified and are there other alternatives that should be explored?" and "Are there significant barriers to the implementation of any of the preferred alternatives, taking into account their state of development and their ability to be integrated into the existing SRS HLW system?"

Stabilization Using Phosphate Bonded Ceramics. Salt Containing Mixed Waste Treatment. Mixed Waste Focus Area. OST Reference #117
Stabilization Using Phosphate Bonded Ceramics. Salt Containing Mixed Waste Treatment. Mixed Waste Focus Area. OST Reference #117

Author:

Publisher:

Published: 1999

Total Pages: 26

ISBN-13:

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Throughout the Department of Energy (DOE) complex there are large inventories of homogeneous mixed waste solids, such as wastewater treatment residues, fly ashes, and sludges that contain relatively high concentrations (greater than 15% by weight) of salts. The inherent solubility of salts (e.g., nitrates, chlorides, and sulfates) makes traditional treatment of these waste streams difficult, expensive, and challenging. One alternative is low-temperature stabilization by chemically bonded phosphate ceramics (CBPCs). The process involves reacting magnesium oxide with monopotassium phosphate with the salt waste to produce a dense monolith. The ceramic makes a strong environmental barrier, and the metals are converted to insoluble, low-leaching phosphate salts. The process has been tested on a variety of surrogates and actual mixed waste streams, including soils, wastewater, flyashes, and crushed debris. It has also been demonstrated at scales ranging from 5 to 55 gallons. In some applications, the CBPC technology provides higher waste loadings and a more durable salt waste form than the baseline method of cementitious grouting. Waste form test specimens were subjected to a variety of performance tests. Results of waste form performance testing concluded that CBPC forms made with salt wastes meet or exceed both RCRA and recommended Nuclear Regulatory Commission (NRC) low-level waste (LLW) disposal criteria. Application of a polymer coating to the CBPC may decrease the leaching of salt anions, but continued waste form evaluations are needed to fully assess the deteriorating effects of this leaching, if any, over time.

Method for Stabilizing Low-level Mixed Wastes at Room Temperature
Method for Stabilizing Low-level Mixed Wastes at Room Temperature

Author:

Publisher:

Published: 1997

Total Pages:

ISBN-13:

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A method to stabilize solid and liquid waste at room temperature is provided comprising combining solid waste with a starter oxide to obtain a powder, contacting the powder with an acid solution to create a slurry, said acid solution containing the liquid waste, shaping the now-mixed slurry into a predetermined form, and allowing the now-formed slurry to set. The invention also provides for a method to encapsulate and stabilize waste containing cesium comprising combining the waste with Zr(OH).sub. 4 to create a solid-phase mixture, mixing phosphoric acid with the solid-phase mixture to create a slurry, subjecting the slurry to pressure; and allowing the now pressurized slurry to set. Lastly, the invention provides for a method to stabilize liquid waste, comprising supplying a powder containing magnesium, sodium and phosphate in predetermined proportions, mixing said powder with the liquid waste, such as tritium, and allowing the resulting slurry to set.

Energy Research Abstracts
Energy Research Abstracts

Author:

Publisher:

Published: 1993

Total Pages: 724

ISBN-13:

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Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.