Introduction - Types and Quantitites of Nuclear Waste - Principles of Waste Management

摘要

In all areas of the nuclear technology and the application of radioisotopes radioactive wastes are generated. The largest amounts arise in nuclear power plants. The radionuclides contained in these wastes, however, have only relatively short half-lifes as a rule. The highest activities are contained in the wastes from the reprocessing of spent nuclear fuels. Most of these wastes as well as the wastes arising from the fabrication of mixed oxide fuels contain actinides. The amounts and activities of the wastes arising from isotope application are in general small compared to those from the nuclear fuel cycle. Wastes with short-lifed radionuclides need only collection and storage until sufficient decay. Dispersion in the environment is frequently applied for noble gases and tritium. The most frequently applied principle in radioactive waste management, however, is concentration and isolation. Several methods are available for this purpose and will be outlined in the lecture. Mechanical filtration and absorption are often applied for the treatment of exhaust air and off-gases. Liquid effluents are mostly cleaning by evaporation, ion exchange of flocculation prior to re-use or discharge. The resulting residues are unmobilized. Solid wastes can be reduced in volume by incineration or baling. For the long-term isolation (disposal) of the conditioned wastes ground disposal, sea dumping and disposal into deep geological formations are available. Their application depends to some degree on the local conditions and the activity level. The radioactive wastes must meet certain criteria for being suitable to disposal. (Atomindex citation 14:762181)