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CHARACTERISTICS OF LOW-LEVEL RADIOACTIVE WASTE
Waste characterization is the determination of the radiological, chemical and physical properties of waste to establish the need for treatment, handling, processing, storage, or disposal of radioactive materials. Typically, characterization is helpful in assessing what must be done to meet the requirements regarding transportation and disposal of radioactive waste.
Radiological waste characterization involves quantifying and detecting the radiation characteristics for the principal radionuclides used in clinical and biomedical research and found in hospital and research-institution waste.
Chemical waste characterization involves the determination of chemical components and properties. It can be accomplished by analyzing waste samples or on the basis of knowledge of the process that generated the waste.
Physical waste characterization involves inspection to determine physical form (solid, liquid, or gas) and other physical properties such as dispersability, and other properties such as compressive strength that might be needed to meet disposal requirements.
Some LLRW contains hazardous materials as defined in 40 CFR 261 (USEPA, 2000). Such LLRW is called mixed waste. Hazardous wastes are defined as wastes that are toxic, corrosive, flammable, or reactive. Mixed waste is regulated as LLRW under 10 CFR 61, and as hazardous waste under 40 CFR 261 (USEPA, 2000). A 1990 survey which profiled commercially generated low-level mixed waste (NUREG/CR-5938), indicated that 140,000 ft3 of mixed wastes was generated in the United States (data from http://www.epa.gov/radiation/mixed-waste/nat_prof.htm ) during that one year. This current generation rate is not related to inventories of mixed waste generated from past generation. Typically, the annual amount of mixed waste generated by the commercial sector which included the biomedical users as small contributors, is much smaller than the amount generated by the Department of Energy. Several effective steps have been taken by generators to reduce the amount of mixed waste (CORAR, 1993).
