Laboratory Optimization Tests of Technetium Decontamination of Hanford Waste Treatment Plant Low Activity WastenOff-Gas Condensate Stimulant.

摘要

The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Off-Gas Condensate) from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. An alternate start-up scenario that is under evaluation is to decontaminate tank waste in another facility, called the LAW Pretreatment System, and send the LAW directly to the LAW melters in WTP without starting up the Pretreatment Facility. This “Direct Feed LAW” (DFLAW) scenario will have a different chemical and radionuclide composition, and thus will have a different Off-Gas condensate composition. To examine the options for disposal of this stream, a simulant is needed for testing. This LAW Off-Gas Condensate stream contains components that are volatile at melter temperatures and are problematic for incorporating into the glass waste form. Under the DFLAW scenario where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, identifying a disposition path becomes vitally important. This report describes the preparation and characterization of a simulant that can be used to examine the potential treatment of this stream to remove radionuclides for subsequent disposition. Options being considered include sending the decontaminated stream to the Effluent Treatment Facility (ETF), for example.