Nuclear waste process monitoring using transient infrared spectroscopy
- Ames Lab., IA (United States); and others
Low level radioactive wastes that contain hazardous metals, as defined by Resource Conservation and Recovery Act (RCRA) regulations, are Low Level Mixed Wastes (LLMW). Effective treatment of LLMW so that the wastes pass waste acceptance criteria, such as Toxicity Characteristic Leaching Procedures (TCLP), is imperative for safe disposal of the waste in landfills. Polymer microencapsulation has been shown to be the most efficient way to treat many types of LLMW, and Transient Infrared Spectroscopy (TIRS) has been shown to be an effective process development tool, as well as a necessary process control system. Polymer microencapsulation isolates and stabilizes wastes by intimately mixing the dried waste with polyethylene in commercially available extruders at temperatures less than 200{degrees}C. The encapsulated waste cools into a form that will meet appropriate waste acceptance criteria. TIRS has been successfully used to monitor the polymer microencapsulation of LLMW at DOE`s Rocky Flats Environmental Technology Site. TIRS is uniquely qualified to perform on-line monitoring because the measurement can be made on moving, IR-opaque viscous liquids, the technique requires only a jet of room temperature air, and data can be updated every 5-10s. Additionally, the rich mid-IR spectrum can be displayed and stored as a permanent record along with the plot of waste loading vs time. The optimization of parameters for TIRS monitoring and its use in the development of the polymer microencapsulation process will be discussed. TIRS has brought the power of IR spectroscopy to the process line.
- OSTI ID:
- 466552
- Report Number(s):
- CONF-951017--
- Country of Publication:
- United States
- Language:
- English
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