Characteristics and Classification of Solid Radioactive Waste From the Front-End of the Uranium Fuel Cycle.

The proper classification of radioactive waste is the basis upon which to define its disposal method. In view of differences between waste containing artificial radionuclides and waste with naturally occurring radionuclides, the scientific definition of the properties of waste arising from the front end of the uranium fuel cycle (UF Waste) is the key to dispose of such waste. This paper is intended to introduce briefly the policy and practice to dispose of such waste in China and some foreign countries, explore how to solve the dilemma facing such waste, analyze in detail the compositions and properties of such waste, and finally put forward a new concept of classifying such waste as waste with naturally occurring radionuclides.

[Problems of safety regulation under radioactive waste management in Russia].

Analysis of the requirements of Federal Law N 190 "About radioactive waste management and incorporation of changes into some legislative acts of the Russian Federation", as well as normative-legislative documents actual and planned to be published related to provision of radiation protection of the workers and the public have been done. Problems of safety regulation raised due to different approaches of Rospotrebnadzor, FMBA of Russia, Rostekhnadzor and Minprirody with respect to classification and categorization of the radioactive wastes, disposal, exemption from regulatory control, etc. have been discussed in the paper. Proposals regarding improvement of the system of safety regulation under radioactive waste management and of cooperation of various regulatory bodies have been formulated.

[Systemic approach to ecologic safety at objects with radiation jeopardy, involved into localization of low and medium radioactive waste].

The article deals with specifying systemic approach to ecologic safety of objects with radiation jeopardy. The authors presented stages of work and algorithm of decisions on preserving reliability of storage for radiation jeopardy waste. Findings are that providing ecologic safety can cover 3 approaches: complete exemption of radiation jeopardy waste, removal of more dangerous waste from present buildings and increasing reliability of prolonged localization of radiation jeopardy waste at the initial place. The systemic approach presented could be realized at various radiation jeopardy objects.

Risk-informed radioactive waste classification and reclassification.

Radioactive waste classification systems have been developed to allow wastes having similar hazards to be grouped for purposes of storage, treatment, packaging, transportation, and/or disposal. As recommended in the National Council on Radiation Protection and Measurements' Report No. 139, Risk-Based Classification of Radioactive and Hazardous Chemical Wastes, a preferred classification system would be based primarily on the health risks to the public that arise from waste disposal and secondarily on other attributes such as the near-term practicalities of managing a waste, i.e., the waste classification system would be risk informed. The current U.S. radioactive waste classification system is not risk informed because key definitions--especially that of high-level waste--are based on the source of the waste instead of its inherent characteristics related to risk. A second important reason for concluding the existing U.S. radioactive waste classification system is not risk informed is there are no general principles or provisions for exempting materials from being classified as radioactive waste which would then allow management without regard to its radioactivity. This paper elaborates the current system for classifying and reclassifying radioactive wastes in the United States, analyzes the extent to which the system is risk informed and the ramifications of its not being so, and provides observations on potential future direction of efforts to address shortcomings in the U.S. radioactive waste classification system as of 2004.

International standards related to the classification and deregulation of radioactive waste.

Although solid radioactive waste management is mainly a national concern, there are some aspects that have international implications. One important example is the decommissioning of nuclear facilities, which results in the release of materials that could be reused and recycled. It is possible that these materials could enter international trade, especially if the material is a metal. It is clearly desirable, therefore, to have appropriate international standards to help regulate trade. This paper describes recent international developments relating to the establishment of radiological criteria for the release of materials from regulatory control (clearance). There have already been some experiences of clearance and the transfer of recycled materials within Europe, and this paper reviews that experience. It also discusses recent developments in relation to the international classification of radioactive waste.

Radionuclide speciation in effluent from La Hague reprocessing plant in France.

Effluent from the La Hague nuclear fuel reprocessing plant was mixed with seawater in order to investigate the fate of the various radionuclides. Thus, a major objective of the present work is to characterize the effluent from La Hague reprocessing plant and to study how the radionuclide speciation changes with time when discharged into the marine environment. Discharges from the La Hague nuclear reprocessing plant represent an important source of artificially produced radionuclides to the North Sea. The transport, distribution, and biological uptake of radionuclides in the marine environment depends, however, on the physicochemical forms of radionuclides in the discharged effluents and on transformation processes that occur after entering the coastal waters. Information of these processes is needed to understand the transport and long-term distribution of the radionuclides. In the present work, a weekly discharged effluent from the nuclear fuel reprocessing plant at Cap La Hague in France was mixed with coastal water and fractionated with respect to particle size and charged species using ultra centrifugation and hollow fiber ultrafiltration with on line ion exchange. The size distribution pattern of gamma-emitting radionuclides was followed during a 62-h period after mixing the effluent with seawater. 54Mn was present as particulate material in the effluent, while other investigated radionuclides were discharged in a more mobile form or were mobilized after mixing with sea water (e.g., 60Co) and can be transported long distances in the sea. Sediments can act as a sink for less mobile discharged radionuclides (Skipperud et al. 2000). A kinetic model experiment was performed to provide information of the time-dependent distribution coefficients, Kd (t). The retention of the effluent radionuclides in sediments was surprisingly low (Kd 20-50), and the sediments acted as a poor sink for the released radionuclides. Due to the presence of non-reacting radionuclide species in the effluent, a major fraction of the radionuclides, such as Cs-isotopes, 106Ru and 125Sb, in the effluent will be subjected to marine transport to the Northern Seas (i.e., the North Sea, Norwegian Sea and the Barents Sea). The La Hague effluent may, therefore, contribute to enriched levels of radionuclides found in the English Channel, including 90Sr, 60Co and Pu-isotopes, and also 106Ru and 125Sb.

A new Hazardous Waste Index.

Hazardous wastes, once generated, have to be stored, transported, treated, disposed off, recycled, depending upon the situation. With laws being tightened, all of the above operations have to be done safely without causing harm to people and environment. Before any operation is carried out, it is vital to know the hazardous characteristics of the waste to be handled. Because waste, generally, is a mixture instead of a pure compound, its hazardous characteristics are difficult to determine and generalize because each waste is specific. A new Hazardous Waste Index (HWI) is proposed in this paper. The index measures hazards related to flammability, reactivity, toxicity and corrosivity as well as the pH value for a hazardous waste. Two examples are given for its use. The index can be modified to include radioactive or mixed waste.