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Melter performance during surrogate vitrification campaigns at the DOE/Industrial Center for Vitrification Research at Clemson University

Description: This report summarizes the results from seven melter campaigns performed at the DOE/Industrial Center for Vitrification Research at Clemson University. A brief description of the EnVitco EV-16 Joule heated glass melter and the Stir-Melter WV-0.25 stirred melter are included for reference. The report discusses each waste stream examined, glass formulations developed and utilized, specifics relating to melter operation, and a synopsis of the results from the campaigns. A `lessons learned` section is included for each melter to emphasize repeated processing problems and identify parameters which are considered extremely important to successful melter operation
Date: October 5, 1995
Creator: Marra, J.C. & Overcamp, T.J.
Partner: UNT Libraries Government Documents Department

Vitrification of simulated radioactive Rocky Flats plutonium containing ash residue with a Stir Melter System

Description: A demonstration trial has been completed in which a simulated Rocky Flats ash consisting of an industrial fly-ash material doped with cerium oxide was vitrified in an alloy tank Stir-Melter{trademark} System. The cerium oxide served as a substitute for plutonium oxide present in the actual Rocky Flats residue stream. The glass developed falls within the SiO{sub 2} + Al{sub 2}O{sub 3}/{Sigma}Alkali/B{sub 2}O{sub 3} system. The glass batch contained approximately 40 wt% of ash, the ash was modified to contain {approximately} 5 wt% CeO{sub 2} to simulate plutonium chemistry in the glass. The ash simulant was mixed with water and fed to the Stir-Melter as a slurry with a 60 wt% water to 40 wt% solids ratio. Glass melting temperature was maintained at approximately 1,050 C during the melting trials. Melting rates as functions of impeller speed and slurry feed rate were determined. An optimal melting rate was established through a series of evolutionary variations of the control variables` settings. The optimal melting rate condition was used for a continuous six hour steady state run of the vitrification system. Glass mass flow rates of the melter were measured and correlated with the slurry feed mass flow. Melter off-gas was sampled for particulate and volatile species over a period of four hours during the steady state run. Glass composition and durability studies were run on samples collected during the steady state run.
Date: October 1, 1996
Creator: Marra, J.C.; Kormanyos, K.R. & Overcamp, T.J.
Partner: UNT Libraries Government Documents Department

Vitrification demonstration with surrogate Oak Ridge Reservation K-25 B and C pond sludge

Description: Surrogate Oak Ridge Reservation (ORR) K-25 B&C Pond sludge was vitrified in a pilot-scale EnVit Co melter operated by Clemson University at the DOE/Industrial Center for Vitrification Research Center. This demonstration was performed for the Savannah River Technology Center (SRTC) in support of a Department of Energy (DOE) - Office of Technology Development (OTD) Technical Task Plan. The intent of the demonstration was to determine the feasibility of vitrifying actual K-25 B&C Pond sludge in an EnVitCo type melter. B&C Pond sludge is a mixed waste consisting primarily of various amounts of Ca, Fe, and Si, with Ni and U as the principal hazardous and radioactive components. The demonstration was successfully completed and homogeneous, durable glass was produced. Characterization of the glass product, as well as details of the demonstration, will be discussed.
Date: July 1, 1996
Creator: Cicero, C.A.; Overcamp, T.J. & Erich, D.L.
Partner: UNT Libraries Government Documents Department

The effect of compositional parameters on the TCLP and PCT durability of environmental glasses

Description: The relationship between glass composition and the chemical durability of environmental waste glass is very important for both the development of glass formulations and the prediction of glass durability for process control. The development of such a model is extremely difficult for several reasons. Firstly, chemical durability is dependent upon the type of leach test employed; the leach tests themselves being only crude approximations of actual environmental conditions or long term behavior. Secondly, devitrification or crystallinity can also play a major role in durability, but is much more difficult to quantify. Lastly, the development of any one model for all glass types is impractical because of the wide variety of wastestreams, the heterogeneity of the wastestreams, and the large variety of components within each wastestream. Several ongoing efforts have been directed toward this goal, but as yet, no model has been proven acceptable.
Date: December 1, 1995
Creator: Resce, J.L.; Overcamp, T.J.; Cicero, C.A. & Bickford, D.F.
Partner: UNT Libraries Government Documents Department

Elemental analysis of waste glass by x-ray fluorescence spectrometry

Description: An X-ray fluorescence (XRF) technique is reported which shows promise for the elemental analysis of low-level mixed waste glasses. This technique can be used for both quantitative laboratory analysis and process control. The glass-forming melts are cast into graphite molds and resulting disks are annealed and polished. The disk is then analyzed with a wavelength dispersive X-ray fluorescence spectrometer and the elemental intensities are converted into concentration with a fundamental parameters routine without the use of matrix-matched standards. Precision of elemental determinations are all better than one percent relative standard deviation. The XRF analysis has been compared with a reference method utilizing conventional wet chemical dissolution techniques followed by atomic spectroscopic determination. Results show that there is no significant difference between these two techniques, however, the XRF technique is much simpler and faster than the wet chemical methods.
Date: May 1, 1995
Creator: Bickford, D.F.; Jurgensen, A.R.; Resce, J.L.; Ragsdale, R.G. & Overcamp, T.J.
Partner: UNT Libraries Government Documents Department

The effect of chemical composition on the PCT durability of mixed waste glasses from wastewater treatment sludges

Description: An experimental program has been designed to examine the chemical durability of glass compositions derived from the vitrification of simulated wastewater treatment sludges. These sludges represent the majority of low-level mixed wastes currently in need of treatment by the US DOE. The major oxides in these model glasses included SiO{sub 2}, Al{sub 2}O{sub 3}, B{sub 2}O{sub 3}, Na{sub 2}O, CaO and Fe{sub 2}O{sub 3}. In addition, three minor oxides, BaO, NiO, and PbO, were added as hazardous metals. The major oxides were each varied at two levels resulting in 32 experimental glasses. The chemical durability was measured by the 7-Day Product Consistency Test (PCT). The normalized sodium release rates (NRR{sub Na}) of these glasses ranged from 0.01 to 4.99 g/m{sup 2}. The molar ratio of the glass-former to glass-modifier (F/M) was found to have the greatest effect on PCT durability. Glass-formers included SiO{sub 2}, Al{sub 2}O{sub 3}, and B{sub 2}O{sub 3}, while Na{sub 2}O, CaO, BaO, NiO, and PbO were glass-modifiers. As this ratio increased from 0.75 to 2.0, NRR{sub Na} was found to decrease between one and two orders of magnitude. Another important effect on NRR{sub Na} was the Na{sub 2}O/CaO ratio. As this ratio increased from 0.5 to 2.0, NRR{sub Na} increased up to two orders of magnitude for the glasses with the low F/M ratio but almost no effect was observed for the glasses with the high F/M ratio. Increasing the iron oxide content from 2 to 18 mole% was found to decrease NRR{sub Na} one order of magnitude for the glasses with low F/M but iron had little effect on the glasses with the high F/M ratio. The durability also increased when 10 mole percent Al{sub 2}O{sub 3} was included in low iron oxide glasses but no effect was observed with the high iron glasses. The ...
Date: January 25, 1995
Creator: Resce, J.L.; Ragsdale, R.G.; Overcamp, T.J.; Bickford, D.F. & Cicero, C.A.
Partner: UNT Libraries Government Documents Department

Vitrification of Cesium-Laden Organic Ion Exchange Resin in a Stirred Melter

Description: The goal of this research was a feasibility study for vitrifying the organic ion exchange resin in a stirred-tank melter. Tests were conducted to determine the fate of cesium including the feed, exit glass, and offgas streams and to assess any impact of feeding the resin on the melter or its performance.
Date: July 9, 1997
Creator: Cicero-Herman, C.A; Sargent, T.N.; Overcamp, T.J. & Bickford, D.F.
Partner: UNT Libraries Government Documents Department

Transportable Vitrification System: Operational experience gained during vitrification of simulated mixed waste

Description: The Transportable Vitrification System (TVS) is a large-scale, fully-integrated, transportable, vitrification system for the treatment of low-level nuclear and mixed wastes in the form of sludges, soils, incinerator ash, and similar waste streams. The TVS was built to demonstrate the vitrification of actual mixed waste at U. S. Department of Energy (DOE) sites. Currently, Westinghouse Savannah River Company (WSRC) is working with Lockheed Martin Energy Systems (LMES) to apply field scale vitrification to actual mixed waste at Oak Ridge Reservation`s (ORR) K-25 Site. Prior to the application of the TVS to actual mixed waste it was tested on simulated K-25 B and C Pond waste at Clemson University. This paper describes the results of that testing and preparations for the demonstration on actual mixed waste.
Date: November 21, 1996
Creator: Whitehouse, J.C.; Burket, P.R.; Crowley, D.A.; Hansen, E.K.; Jantzen, C.M.; Smith, M.E. et al.
Partner: UNT Libraries Government Documents Department