Waste classification system applicability

This Report is concerned with classification of hazardous waste for purposes of disposal. However, the principles and concepts embodied in the waste classification system could be applied in classifying hazardous materials for any other purpose. The classification system is intended to be applied to hazardous waste prior to disposal. It is not intended to be applied to screening or ranking of contaminated sites, including existing hazardous waste disposal sites, because these activities involve site-specific considerations that cannot be included in a generally applicable waste classification system. However, any wastes exhumed from contaminated sites that then require disposal would be included in the waste classification system. 

This Report presents the foundations and technical principles for development of a generally applicable and risk-based hazardous waste classification system. Recommendations on suitable approaches to establishing boundaries of different waste classes are discussed these boundaries could be expressed, for example, in terms of limits on concentrations of hazardous substances. However, a particular implementation of the proposed waste classification system in terms of quantifying the boundaries of different waste classes is not presented. 

Thus, NCRP s recommendations focus on the technical foundations for a generally applicable and risk-based waste classification system. 

Development of a waste classification system based on considerations of risks to the public requires assumptions about generic exposure scenarios (i.e., exposure scenarios that are generally applicable at any disposal site). 

In most cases, evaluations of ecological impacts are site-specific and, as a consequence, are not considered when establishing a generally applicable waste classification system. These impacts normally are addressed in disposal site selection, design, and operation, and they may be used in establishing waste acceptance criteria for the site. To the extent that ecological impacts can be evaluated generi-cally, NCRP believes that the principles and framework for risk-based waste classification presented in this Report are sufficiently flexible to take them into account. 

Generally applicable waste classification system proposed by Kocher and Croff. In response to the definition of high-level waste in Clause (B) of NWPA (1982) discussed in Section 4.1.2.3.1, Kocher and Croff (1987 1988) developed a proposal for a quantitative, generally applicable, and risk-based radioactive waste classification system that addresses the definitions of high-level waste in... 

Application of NCRP Recommendations to Waste Classification. NCRP s recommendations on dose limits and a negligible dose for individual members of the public, and their associated cancer risks, could be used in developing a risk-based waste classification system. Specifically, the dose limits applicable to all man-made sources of exposure combined could be used in establishing concentration limits of radionuclides or hazardous chemicals in dedicated hazardous waste disposal facilities based on assumed scenarios for exposure of the public. Similarly, the negligible individual dose could be used in establishing concentration limits of radionuclides in disposal facilities for nonhazardous waste. These applications are discussed in Sections 6.2 and 6.3 where NCRP s recommendations on risk-based waste classification are presented. 

The provision of the National Energy Policy Act (NEPA, 1992) that prohibits NRC from establishing dose criteria that could be used to exempt radioactive wastes from licensing requirements for disposal clearly is an impediment to development of generally applicable exemption levels for radioactive waste. An exempt class of radioactive and hazardous chemical waste is the cornerstone of the risk-based waste classification system developed in this Report, and any legal and regulatory impediments to establishment of generally applicable exemption levels would need to be removed. 

Example Applications of the Risk-Based Waste Classification System... 

This Section provides example applications of the recommended risk-based waste classification system to a variety of hazardous wastes to illustrate its implementation and potential ramifications. Disposal is the only disposition of waste considered in these examples. In Section 7.1.1, a general set of assumptions for assessing the appropriate classification of hazardous wastes is developed, including a variety of assumed exposure scenarios for inadvertent intruders at waste disposal sites and assumed negligible and acceptable risks or doses from exposure to radionuclides and hazardous chemicals. Subsequent sections apply the methodology to several example wastes. 

An ideal system for classifying hazardous wastes should be risk-based, applicable to all wastes that contain radionuclides or hazardous chemicals, internally consistent, based on intrinsic waste properties, comprehensible, quantitative, and compatible with existing or feasible data and methods. To the extent that these attributes are lacking in a waste classification system, undesirable consequences are likely to result. 

DORNSIFE, W.P. (1995). Practical applications of a risk-based waste classification system, pages 113 to 145 in Radioactive and Mixed Waste—Risk as a Basis for Waste Classification, NCRP Symposium Proceedings No. 2 (National Council on Radiation Protection and Measurements, Bethesda, Maryland). 

NCRFs recommendations on classification of hazardous wastes are based on two principles. First, a classification system should be generally applicable to any waste that contains radionuclides, hazardous chemicals, or mixtures of the two (i.e., the system should be comprehensive). Second, waste that contains hazardous substances should be classified based on considerations of health risks to the public that arise from waste disposal, because permanent disposal is the intended disposition of materials having no further use. 

Many other individual applications for decanters exist, outside the classifications already covered. In the agricultural sector, decanters are used to dewater pig manure, as well as other farming wastes. In the mechanical engineering sector, as well as the cutting and lubricating oil recycle systems, there is the removal of accumulated impurities from electroplating and electrochemical machining solutions. 

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