Standard and modified electrode engineering-scale in situ vitrification tests

Technical Report · Tue Sep 01 00:00:00 EDT 1992

DOI:https://doi.org/10.2172/7023669· OSTI ID:7023669

Thompson, L E; Tixier, J S ^[1]; Winkelman, R G ^[2]

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1. Pacific Northwest Lab., Richland, WA (United States)
2. Geosafe Corp., Richland, WA (United States)

This report describes engineering-scale in situ vitrification (ISV) electrode tests conducted by Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE).(a) The purpose of these tests was to establish baseline data to serve as a foundation on which to improve the design of standard graphite rod electrodes, which are currently used in all applications. Changes in electrode design are proposed as one method to increase ISV melt depths that typically reach about 5 m. Melt depths of 10 m are needed to remediate some contaminated soil sites within the DOE complex. To establish baseline data, we performed a thermal distribution analysis and tested three electrode designs: (1) the standard graphite rod electrodes, (2) a modified design referred to as the composite graphite/molybdenum electrode, and (3) a second modified design, the dilated-tip graphite electrode. In total we performed six tests, two of each design. Within the scope of these tests, there were four specific objectives. Our first objective was to determine the influence of electrode design on monolith mass and shape. Our second objective was to determine the correlation between the actual test results and the results of the numerical heat distribution analysis using the TEMPEST code. Our third objective was to qualitatively evaluate the melt resistance and the electrode contact resistance that resulted from the three electrode designs. Finally, our fourth objective was to verify the reproducibility of the engineering-scale test results.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 7023669
• Report Number(s): PNL-8294; ON: DE93000479
• Country of Publication: United States
• Language: English

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