Depth enhancement techniques for the in situ vitrification process
- Pacific Northwest Lab., Richland, WA (United States)
- Geosafe Corp., Richland, WA (United States)
In-situ vitrification (ISV) is a process by which electrical energy is supplied to a soil/waste matrix. The resulting Joule heat raises the temperature of the soil/waste matrix, producing a pool of molten soil. Since its inception, there have been many successful applications of the technology to both staged and actual waste sites. However, there has been some difficulty in extending the attainable treatment melt depth to levels greater than 5 m. Results obtained from application of two novel approaches for extending the ultimate treatment depth attainable with in-situ vitrification (ISV) are presented. In the first, the electrode design is modified to concentrate the Joule heat energy delivered to the soil/waste matrix in the lower region of the target melt zone. This electrode design has been dubbed the hot-tip electrode. Results obtained from both computational and experimental investigations of this design concept indicate that some benefit toward ISV depth enhancement was realized with these hot-tip electrodes. A second, alternative approach to extending process depth with ISV involves initiating the melt at depth and propagating it in either vertical direction (e.g., downward, upward, or both) to treat the target waste zone. A series of engineering-scale experiments have been conducted to assess the benefits of this approach. The results from these tests indicate that ISV may be effectively initiated and sustained using this subsurface start-up technique. A survey of these experiments and the associated results are presented herein, together with brief discussion of some considerations regarding setup and implementation of this subsurface start-up technique.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 28246
- Report Number(s):
- PNL-SA-24899; CONF-941124-20; ON: DE95007802; TRN: 95:008395
- Resource Relation:
- Conference: 33. Hanford symposium on health and the environment: symposium on in-situ remediation--scientific basis for current and future technologies, Richland, WA (United States), 7-11 Nov 1994; Other Information: PBD: Nov 1994
- Country of Publication:
- United States
- Language:
- English
Similar Records
Subsidence above in situ vitrification: Evaluation for Hanford applications
In situ vitrification of transuranic wastes: An updated systems evaluation and applications assessment