Equipment evaluation for low density polyethylene encapsulated nitrate salt waste at the Rocky Flats Plant
Mixed wastes at the Rocky Flats Plant (RFP) are subject to regulation by the Resource Conservation and Recovery Act (RCRA). Polymer solidification is being developed as a final treatment technology for several of these mixed wastes, including nitrate salts. Encapsulation nitrate salts with low density polyethylene (LDPE) has been the preliminary focus of the RFP polymer solidification effort. Literature reviews, industry surveys, and lab-scale and pilot-scale tests have been conducted to evaluate several options for encapsulating nitrate salts with LDPE. Most of the effort has focused on identifying compatible drying and extrusion technologies. Other processing options, specifically meltration and non-heated compounding machines, were also investigated. The best approach appears to be pretreatment of the nitrate salt waste brine in either a vertical or horizontal thin film evaporator followed by compounding of the dried waste with LDPE in an intermeshing, co-rotating, twin-screw extruder. Additional pilot-scale tests planned for the fall of 1993 should further support this recommendation. Preliminary evaluation work indicates that meltration is not possible at atmospheric pressure with the LDPE (Chevron PE-1409) provided by RFP. However, meltration should be possible at atmospheric pressure using another LDPE formulation with altered physical and rheological properties: Lower molecular weight and lower viscosity (Epoline C-15). Contract modifications are now in process to allow a follow-on pilot scale demonstration. Questions regarding changed safety and physical properties of the resultant LDPE waste form due to use of the Epoline C-15 will be addressed. No additional work with non-heated mixer compounder machines is planned at this time.
- Research Organization:
- EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC34-90DP62349
- OSTI ID:
- 10190164
- Report Number(s):
- RFP-4779; ON: DE94001769; TRN: 93:023091
- Resource Relation:
- Other Information: PBD: 30 Aug 1993
- Country of Publication:
- United States
- Language:
- English
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Review of the radioactive and thermal stability of low density polyethylene encapsulated nitrate salt waste
Review of the radioactive and thermal stability of low density polyethylene encapsulated nitrate salt waste
Related Subjects
ROCKY FLATS PLANT
RADIOACTIVE WASTE PROCESSING
NITRATES
ENCAPSULATION
POLLUTION CONTROL EQUIPMENT
EVALUATION
WASTES
SOLIDIFICATION
RESOURCE CONSERVATION
RADIOACTIVE WASTES
SALTS
EXTRUSION
POLYETHYLENES
WASTE MANAGEMENT
BRINES
EVAPORATORS
NONRADIOACTIVE WASTES
POLLUTION CONTROL
NONRADIOACTIVE WASTE MANAGEMENT
052001
WASTE PROCESSING