Other Radioactive Waste Classification Systems

As part of this study, proposed radioactive waste classification systems that differ from the existing classification system in the United States were reviewed and evaluated. Of particular interest is the classification system currently recommended by the International Atomic Energy Agency (IAEA). This classification system and the disposal options for each waste class are summarized in Table 1.2. The basic waste classification system consists of exempt waste, low-and intermediate-level waste, and high-level waste. 

The radioactive waste classification system recommended by IAEA differs from the existing classification system in the United States in the following respects. 

Concentrations of radionuclides at or below levels corresponding to annual dose to members of the public from waste disposal of 10 p.Sv 

Concentrations of radionuclides above exempt levels and thermal power density less than about 2 kWm  

Concentrations of long-lived, alpha-emitting radionuclides restricted to 4 kBq g 1 in individual waste packages and average of 0.4 kBq g 1 over all waste packages 

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This Section discusses the historical development and current approaches to classification and disposal of radioactive waste. Classification and requirements for disposal of different radioactive wastes in the United States are emphasized, particularly the relationship between waste classification and requirements for disposal much of this discussion is adapted from a previous paper (Kocher, 1990). Proposals for alternative radioactive waste classification systems are reviewed. Classification systems developed by the International Atomic Energy Agency (IAEA) and the relationship between waste classification and disposal requirements in IAEA recommendations are discussed in some detail. Waste classification systems developed in other countries are briefly mentioned. 

Not discussed in this Section are radioactive waste classification systems developed in other countries, particularly in Europe. Waste classification systems in European countries are discussed, for example, in a report of the Commission of the European Communities (CEC, 1990), and waste classification systems in a number of countries have been reviewed by Numark et al. (1995). The waste classification systems developed in other countries often have been based, at least in part, on the source-based classification system in the United States or the various IAEA recommendations discussed in this Section they generally do not include any new concepts of waste classification. 

The basic waste classification system does not distinguish between radioactive waste associated with the nuclear fuel-cycle and other waste i.e., fuel-cycle and NARM wastes are included in the same classification system. 

DOE s high-level wastes as if they were among the most hazardous of all radioactive wastes. However, the concentrations of hazardous substances in some of these wastes are similar to those in low-level radioactive waste that is normally intended for disposal in near-surface facilities. In contrast, some chemical wastes that are highly hazardous, compared with other wastes, and nondegradable are being sent to near-surface disposal facilities. Both of these situations occur largely because of the source-based aspects of existing waste classification systems. 

KOCHER, D.C. and CROFF, A.G. (1987). A Proposed Classification System for High-Level and Other Radioactive Wastes, Oak Ridge National Laboratory Report ORNL/TM-10289 (National Technical Information Service, Springfield, Virginia). 

There also are two important differences. First, the classification system for radioactive waste from the nuclear fuel cycle includes different classes that are defined based essentially on the source of the waste. In addition, some classes of fuel-cycle waste (e.g., high-level waste) often, but not always, contain higher concentrations of radionuclides than other classes (e.g., low-level waste) and, thus, pose a greater hazard in waste management and disposal. The classification system for hazardous chemical waste does not distinguish between hazardous wastes based on their source, with the exception of the K list of wastes from specific sources. Additionally, hazardous chemical wastes are not further classified based on their relative hazard (i.e., there is only one class of hazardous chemical waste). 

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