Radioactive wastes from nuclear

The properties of hydrated titanium dioxide as an ion-exchange (qv) medium have been widely studied (51—55). Separations include those of alkaH and alkaline-earth metals, zinc, copper, cobalt, cesium, strontium, and barium. The use of hydrated titanium dioxide to separate uranium from seawater and also for the treatment of radioactive wastes from nuclear-reactor installations has been proposed (56). 

HLW comprises most of the radioactivity associated with nuclear waste. Because that designation can cover radioactive waste from more than one source, the term spent nuclear fuel (SNF) will be used to discuss HLW originating from commercial nuclear reactors. LLW comprises nearly 90 percent of the volume of nuclear waste but little of the radioactivity. Nuclear power reactors produce SNF and most of the nation s LLW, although there are approximately 20,000 different sources of LLW. The name SNF is a bit of a misnomer because it implies that there is no useful material left in the fuel, when in fact some fissionable material is left in it. 

The worst nuclear accident occurred in 1951 in Russia when radioactive waste from Pu production was dumped into a lake. 

Disposal of radioactive wastes from nuclear reactors has proved to he a serious political problem. The NIMBY syndrome (not in my backyard) applies here. 

Low level waste from commercial facilities is buried on site. The Nuclear Regulatory Commission (NRC) has projected the activities and volumes of low level radioactive waste from all sources buried at commercial sites to the year 2000 using information from the Idaho National Environmental and Engineering Laboratory (INEEL) waste retrieval project and assuming that the waste disposal practices then used would continue into the future. The 20-year decayed 241Am and 243Am concentrations were estimated to be 380 and 230 pCi/m3 (14 and 8.5 Bq/m3), respectively (Kennedy et al. 1985). 

This is acceptable only for very toxic materials and radioactive wastes from the nuclear industry. 

Brezhneva, N. E., Oziraner, S. G., Minaev, A. A. Kuztetsov, D. G. 1976. Properties of phosphate and silicate glasses for solidification of radioactive wastes. In Management of Radioactive Wastes from the Nuclear Fuel Cycle. IAEA, Vienna, 2, 85-94. 

Vlasov, V. I., Kedrovsky, O. L., Polyakov, A. S. Shishtchitz, I. Y. 1987. Handling of liquid radioactive waste from the closed nuclear fuel cycle. In Back End of the Nuclear Fuel Cycle Strategies and Options. IAEA, Vienna, 109-117. 

Dyer, R.S., "Environmental surveys of two deep sea radioactive waste disposal sites using submersibles" in Symposium, Management of Radioactive Waste from the Nuclear Fuel Cycle, IAEA, 317-338, 1976. 

J. E. Mendel, W. A. Ross, F. P. Roberts, R. P. Turcotte, Y. B. Katayama and J. H. Westsik, Jr., Thermal and Radiation Effects on BorosUicate Waste Glasses. In IAEA Symposium on Management of Radioactive Waste from the Nuclear Fuel Cycle, IAEA-SM-207/100, 2 49, Vienna, 1976. 

The counting techniques described in this paper are also readily applicable to studies of "hot radioactive waste (z.e.j radioactive waste from reprocessed nuclear fuel). With this type of material, the cesium can be analyzed as 30-y (662-keV y), the RE as 13-y Eu (964-keV and 1408-keV y), strontium as 28-y Sr (after chemical separation and beta counting), and the actinides by group separation and alpha counting. 

Harmful chemical spills can often be cleaned up by treatment with another chemical. A spill of H2SO4, for example, can be neutralized by adding NaHC03. Why can t harmful radioactive wastes from nuclear power plants be cleaned up just as easily ... 

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). 

The CTH actinide separation process was developed as a possible means to reduce the expected long term dose to man from a geologic repository containing solidified radioactive waste from the reprocessing of spent nuclear fuel The distribution data for the elements present in significant amounts in the high level liquid waste (HLLW) from a Purex plant, the general principles and the flowsheet have been described in detail elsewhere A... 

Radioactive waste from certain nuclear power plants and from weapons testing can lead to health problems. For example, ions of the radioactive isotope strontium-90, an alkali metal, exhibit chemical behaviour similar to calcium ions. This leads to incorporation of the ions in bone tissue, sending ionizing radiation into bone marrow, and possibly causing leukemia. Given the following equation for the decay of strontium-90, how would you complete it ... 

On the other hand, there is the question of disposal of domestic and general industrial wastes. There are toxic wastes which require more careful handling. Of particular concern are radioactive wastes from nuclear power stations. With the latter, there are stringent regulations for safe disposal to minimize contamination of the land surface and neighboring surface waters. 

Our society has not had a very impressive record for safe disposal of industrial wastes. We have polluted our water and air, and some land areas have become virtually uninhabitable because of our improper burial of chemical wastes. As a result, many people are wary about the radioactive wastes from nuclear reactors. The potential threats of cancer and genetic mutations make these materials especially frightening. 

Intemational Atomic Energy Agency, Management of Radioactive Wastes from the Nuclear Fuel Cycle, Vols. 1 and 2, IAEA, Vienna, 1976... 

Figure 5.43. Activity of radioactive waste from nuclear power plants after 40 years of continuous operation, indicating the advantage of accelerator-breeder concepts. The calculations are preliminary and do not correspond to expected final designs (based on Rubbia etal., 1995 Lung, 1997).

Robertson, D.E., Smith, M.R., Doppenaal, D.W., Kiddy, A.R., Strebin, R.S., Concentrations and behaviour of l, Tc, and C in low-level radioactive wastes from commercial nuclear power stations. Waste Manage., 2 (1991) 287. 

Beamer, N.V. et. ah, Conditioning CANDU reactor wastes for disposal management of radioactive waste from nuclear power plants. In Proceedings of a Seminar, Karlsruhe, 1981, International Atomic Energy Agency, lAEA-TECDOC 276, Vienna, 1983. 

Laboratory and pilot plant experiments carried out at INCT showed that reverse osmosis is very useful for the treatment of liquid low-level radioactive wastes from Polish nuclear laboratories. However, to reach high decontamination the process should be arranged as a multistage operation with microfiltration or ultrafiltration pretreatment [32,33]. 

Reverse osmosis preceded by microfiltration or ultrafiltration is considered as an option for the treatment of radioactive wastes from Romanian nuclear centers. Effective studies are carried on at Research Center for Macromolecular Materials and Membranes, Bucharest and at Institute of Nuclear Research, Pitesti aiming in employing these pressure-driven techniques for cleaning the wastes from decontamination of nuclear installations and reactor primary circuit [34,35]. 

TTigh-level radioactive wastes from nuclear fuel reprocessing are pres-... 

The safe disposal of the radioactive wastes from nuclear reactors is an important and controversial matter. A variety of proposals have been made, including the burial of radioactive waste in deep mines on either a recoverable or a permanent basis, burial at sea, and launching the waste into outer space. The first alternative is the only one that appears credible. The essential requirement is that the disposal site(s) be stable with respect to possible earthquakes or invasion by underground water. Spent nuclear fuel can be encased in blocks of borosilicate glass, packed in metal containers, and buried in stable rock formations. For a nuclide such as whose half-life is 24,000 years, a storage site that is stable over... 

Haug, H. 0., "Production, Disposal, and Relative Toxicity of Long-Lived Fission Products and Actinides in the Radioactive Wastes from Nuclear Fuel Cycles," (in German), KFK-2022, translated as 0RNL-tr-it302, Oak Ridge National Laboratory,... 

Bebbington, William P., "The Reprocessing of Nuclear Fuel", Scientific American, Vol. 235, No. 6, December 1976, Page 30 Cohen, Bernard L., "The Disposal of Radioactive Waste from Fission Reactors", Scientific American, Vol. 236, No. 6, June 1977, Page 21... 

One of the problems associated with the storage of radioactive wastes from nuclear power plants is that some of the nuclides remain radioactive for a very long time. An example is plutonium-239, which has a half-life of 2.44 x 10 years. What fraction of plutonium-239 is left after 9.76 x 10 years ... 

Another potential source of energy is nuclear fission, but because of environmental concerns about the radioactive wastes from fission processes, the future of the nuclear... 

---