RCRA CLOSURES AT THE INEEL'S WASTE EXPERIMENTAL REDUCTION FACILITY

摘要

This paper discusses the current, ongoing project to perform Resource Conservation and Recovery Act (RCRA) closure on a number of mixed low-level waste (MLLW) treatment processes installed within the Waste Reduction Operations Complex at the Idaho National Engineering and Environmental Laboratory (INEEL). The process units currently being closed include three units at the Waste Experimental Reduction Facility (WERF): ? A hazardous/mixed waste incinerator unit ? Two stabilization units (both paddle mixer and drum tumbler) ? A sort, size, and segregation unit. A RCRA closure plan was developed for each unit and submitted to the Idaho Department of Environmental Quality (IDEQ). The proposed strategy presented in each closure plan established a clearly defined path for completing the closures and was critical to their successful completion. Each plan established the following: ? The system boundary affected by closure ? Waste residuals (bottom ash, baghouse dust, etc.) requiring removal prior to equipment dismantlement ? Process equipment requiring dismantlement and removal ? Closure performance standards ? Methods for achieving closure performance standards ? Waste disposition. The closure activities for WERF were performed by an in-house dedicated deactivation, decontamination, and dismantlement (DD&D) organization. Typically, the DD&D organization performs field activities in a facility that is no longer operational or manned. The WERF is unique in that the facility must remain operational to support MLLW storage operations. The strategy for performing the fieldwork on these closures was to first isolate the utilities that serviced only the units that were being removed. After isolations were complete, the uncontaminated equipment was removed, followed by removal of residual waste and contaminated equipment. The DD&D-planned removal activities were modified throughout the closure process as more innovative removal techniques were developed. For example, the incinerator chambers and baghouses were removed using air module systems (air pallets) instead of removing the facility roof and using a crane to remove the equipment. Final decontamination activities of the facility walls and floors were performed on the affected areas, following the dismantlement and removal activities. To verify clean closure, samples of the final rinse water were collected and analyzed for the constituents of concern. Upon receipt of these analyses, an independent professional engineer will certify the closure. Mixed hazardous low-level radioactive waste was sent to an off-Site permitted Treatment, Storage, and Disposal Facility (TSDF) for treatment (macroencapsulation, stabilization, etc.) and was disposed of in a RCRA Subtitle C landfill. Ancillary equipment that is industrial waste was disposed of in the INEEL Landfill Complex and low-level radioactive waste was disposed of at the Radioactive Waste Management Complex (RWMC) located at the INEEL.