Characterization of radioactive hazardous waste

Abstract

The characterization of radioactive hazardous waste, also known as transuranic "mixed waste" has to be completed before it can be classified for proper treatment (incinerator, mechanical compaction or thermal treatment), packing, and transport. The characterization of the TRU mixed waste is not only complex process but rather an expensive undertaking. The process knowledge is the basic foundation of characterization. It is the documented knowledge of processes and materials that generated the waste. The transuranic waste Quality Assurance Program Plan (QAPP) defines the Data Quality Objectives (DQO's) and provides the scope of analytical parameters and methods required to accurately characterize the radioactive mixed waste. Based on the historical data and process knowledge a sampling and analysis plan can be developed to characterize the radioactive hazardous waste. Based on the characterization, an assessment of the regulatory status can be made before the waste could be accepted for disposal at the WIPP facility. The Waste Acceptance Criteria (WAC) developed by WIPP defines the parameters for receiving and final disposal of the TRU waste. The sets of criteria, such as: heat generated, fissile gram equivalent (FGE), plutonium-equivalent (PE) curies, and specifications of a dose rate have to be met before the waste is accepted for deep geological disposal. The characterization of radioactive waste becomes even more complex due to the presence of iron base metals/alloys, aluminum base metals/alloys, organic, chelating agents that are mixed with plastic, rubber, cellulose, soils and cement. Some of the modern characterization technologies that are under development and currently used for TRU mixed wastes are: nondestructive examination, nondestructive assay, headspace gas analysis, and drum coring for Resources Conservation Recovery Act (RCRA) sampling.