Radioactive waste definition

Review work for future updates of our data base should focus on iron compounds and complexes. The iron system is thought to be of crucial importance for characterizing the redox behaviour of radioactive waste repositories. Preliminary applications have indicated that the lack of data for the iron system is a source of major uncertainties associated with the definition of an oxidation potential. Hence, there is little use in developing sophisticated redox models for radionuclides as long as the dominant redox processes in a repository are poorly known. 

Conceptual design studies for WIPP have been completed and architect engineering definition is now underway. A DOE Preliminary Environmental Impact Statement will be released by January, 1979. Present schedules call for construction to start in 1981 and for completion in 1985. First radioactive waste shipments could be accomodated in the spring of 1986. 

The use of inorganic ion exchangers to solidify liquid radioactive waste followed by pressure sintering to produce a ceramic waste form appears to be a viable alternative to calcina-tion/vitrification processes. Both the process and waste form are relatively insensitive to changes in the composition of the waste feed. The stability of the ceramic waste form has been shown to be superior to vitrified wastes in leaching studies at elevated temperatures. Further studies on the effects of radiation and associated transmutation and the influence of temperature regimes associated with potential geologic repositories are needed for a more definitive comparison of crystalline and amorphous waste forms. 

Table 1.1—Summary of current definitions of radioactive waste classes and intended disposal systems for... 

Some wastes are defined by exclusion (i.e., by what they are not), not on the basis of their properties or associated risks. Low-level radioactive waste is defined as waste that is not high-level waste, spent fuel, transuranic waste, or uranium or thorium mill tailings. Because the excluded wastes are defined by their source, rather than their properties, the definition of low-level waste is not based on properties of the waste and wastes in this class can vary from essentially innocuous to highly hazardous over long time frames. 

Early Descriptions of Radioactive Waste Categories. The following sections discuss the earliest categories of radioactive waste that were developed prior to the current legal and regulatory definitions of waste classes. These categories applied only to waste that arises from operations of the nuclear fuel cycle. 

Statutory and Regulatory Definitions. The earliest statutory definitions of transuranic waste were contained in AEA (1954), the National Security and Military Applications of Nuclear Energy Authorization Act (NSMA, 1980), and the Low-Level Radioactive Waste Policy Act (LLRWPA, 1980). All of these laws defined transuranic waste in terms of concentrations of long-lived, alpha-emitting... 

Statutory and Regulatory Definitions. Current statutory definitions of low-level waste are contained in NWPA (1982) and the Low-Level Radioactive Waste Policy Amendments Act (LLRWPAA, 1986). In the Nuclear Waste Policy Act, low-level waste is defined as radioactive waste that ... 

The statutory definitions of low-level waste apply only to radioactive waste that arises from operations of the nuclear fuel cycle i.e., to waste that contains source, special nuclear, or byproduct material as defined in AEA (see Section 4.1.2.1). This restriction, although not explicit in the definitions, is indicated by the applicability of NWPA and LLRWPAA to fuel-cycle waste only and by the reference to NRC, which can only regulate fuel-cycle waste. Thus, low-level waste does not include NARM waste. 

NRC has developed licensing criteria for near-surface disposal of waste that contains source, special nuclear, or byproduct materials in 10 CFR Part 61 (NRC, 1982a). These regulations are intended to apply primarily to disposal of commercial low-level waste. They do not include a definition of low-level waste but essentially defer to the current statutory definition in the Low-Level Radioactive Waste Policy Amendments Act of 1985. Thus, low-level waste can include wastes with high concentrations of radionuclides that are not generally acceptable for near-surface disposal in accordance with the licensing criteria in 10 CFR Part 61 (NRC, 1982a). 

Some definitions of low-level waste differ from the one summarized above. In particular, transuranic waste is not excluded in the definition in the Low-Level Radioactive Waste Policy Amendments Act of 1985, and transuranic waste thus is a form of low-level waste. However, this inconsistency has little practical significance, because the Amendments Act governs disposal of commercial low-level waste only, unless DOE waste is sent to a commercial facility, and there is very little commercial transuranic waste requiring disposal. 

Concepts and definitions. Two concepts are potentially useful in establishing exemption levels for radioactive waste. The first is the concept of a generally applicable negligible (de minimis) dose or risk, and the second is the concept of amounts of radionuclides that are exempt or below regulatory concern (BRC) for particular practices or sources. 

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... 

Clauses (A) and (B) of the Act, as well as the definitions of other waste classes. In this proposal, all radioactive waste would be placed into one of three classes, which are defined conceptually as follows ... 

It is highly desirable that a waste classification system be expressed in quantitative terms. More specifically, the intrinsic waste characteristics that define the boundaries between waste classes should be stated numerically. Qualitative definitions of waste classes, such as the definition of high-level radioactive waste discussed in Section 4.1.2.3.1, simply defer the issue of waste classification to a subsequent definition of the qualitative terms or to case-by-case determinations that typically occur after waste is generated. 

In addition, the reliance on generic scenarios for inadvertent intrusion in classifying waste cannot, by definition, represent site-specific risks. However, this is not a serious shortcoming because such scenarios have been used in establishing subclasses of low-level radioactive waste for disposal in near-surface facilities (NRC, 1982a). Furthermore, as emphasized in this Report, establishment of a risk-based waste classification system using particular exposure scenarios does not obviate the need to perform site-specific risk assessments for the purpose of establishing waste acceptance criteria at each disposal site. 

A striving to embody all the desired attributes of the new system, while recognizing that this may take many years and that a number of important benefits can be obtained by interim implementation of parts of the system. The most important areas in which interim implementations are likely to be beneficial include the establishment of exemption levels for radionuclides and hazardous chemicals in waste, to allow hazardous wastes to be managed as nonhazardous material or to allow mixed waste to be managed as radioactive or hazardous chemical waste only, and the elimination of source-based definitions of hazardous wastes, especially radioactive wastes. 

NRC (1987). U.S. Nuclear Regulatory Commission. 10 CFR Part 60—Definition of high-level radioactive waste , Advance notice of proposed rule-making, 52 FR 5992 (U.S. Government Printing Office, Washington). 

This volume covers ongoing research and, thus, leaves many questions unanswered and many problems unsolved. The geochemistry of disposed radioactive wastes involves many complex issues that will require years of additional research to resolve. High-priority problems include integration of geochemical data with computer models of chemical interaction and transport, definition of environmental conditions that affect the behavior of radionuclides at specific disposal sites, evaluation of complex formation of dissolved radionuclides with inorganic and organic complexants, and determination of radionuclide solubilities in natural waters. 

For a sample volume of 0.5 L, a counting efficiency 7790-2 of 49 %, and a chemical yield around 80 %, the calculated LLD is approximately 0.02 Bq/L (k=2). This value is definitely lower than the maximum concentration of Sr authorized in Belgium in the rejections of aqueous radioactive waste (max. 36 Bq/L). ... 

Radioactive waste is any material that contains, or is contaminated with, radionuclides at concentrations of radionuclides greater than the exempted quantities established by the regulatory body and for which no future use is foreseen. This is after a definition by IAEA. 

Regulatory Definition of Hazardous, Radioactive, and Mixed Waste. Existing federal regulations give specific regulatory definitions for all waste types. Wastes that are of most Interest to environmental restoration and waste management are hazardous waste, radioactive waste, and mixed waste. 

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