Thermoplastic encapsulation of commercial reactor low level radioactive, hazardous and mixed wastes
Conventional hydraulic cement solidification is the primary technology employed by the U.S. Department of Energy (DOE) and commercial nuclear facilities for treatment of low-level radioactive (LLW), hazardous and mixed wastes. The extensive use of cement as a solidification binder has been based on its availability, relative low cost, processability, and high alkalinity (beneficial for immobilizing toxic metals). However, a chemical hydration reaction necessary to set and cure the waste form limits the type and quantity of waste that can be incorporated due to possible interferences between the waste and binder material. Alternative encapsulation technologies have been sought under DOE sponsorship that provide increases in waste stream compatibility, waste loading potential, and waste form performance at lower costs. The Environmental & Waste Technology Center (E&WTC) at Brookhaven National Laboratory (BNL) has developed several low temperature encapsulation processes for improved treatment of commercial reactor and DOE waste streams, using low-density polyethylene and sulfur polymer. Process development studies have shown successful process applicability to a wide range of wastes including evaporator concentrates, such as sodium sulfate and borate salts, incinerator ash and ion exchange resins. Waste form performance studies have been conducted to characterize waste form behavior under disposal conditions in accordance with testing criteria specified by the Nuclear Regulatory Commission (NRC) and the Environmental Protection Agency (EPA). Based on processing and performance considerations, dramatic waste loading improvements compared with conventional hydraulic cement have been achieved. For example, the polyethylene process has been shown to encapsulate up to 70 dry wt% evaporator salt concentrates, compared with a maximum of about 12 dry wt% for the best hydraulic cement formation.
- Research Organization:
- Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Williams (Paul) and Associates, Medina, OH (United States)
- OSTI ID:
- 133023
- Report Number(s):
- EPRI-TR-105134; CONF-940746-; TRN: 96:005320
- Resource Relation:
- Conference: International conference on low-level waste (LLW), Norfolk, VA (United States), 24-26 Jul 1994; Other Information: PBD: May 1995; Related Information: Is Part Of Proceedings: 1994 EPRI International Low Level Waste Conference; PB: 825 p.
- Country of Publication:
- United States
- Language:
- English
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