Anthropogenic radionuclide emissions into the environment
Two sources contribute essentially to the presence of anthropogenic radioisotopes in the environment: (i) release from nuclear materials with a major fraction derived from the nuclear bomb testing period during the period 1950–1963 and (ii) emissions from the nuclear industry, such as waste waters from U-mine tailing or nuclear fuel reprocessing plants. This chapter focuses mainly on the major source responsible for global surface contamination, that is, radioisotope aerosol deposition after release into the atmosphere. The atmospheric emissions were caused mainly via surface atomic bomb tests and reactor accidents, with the Chernobyl reactor catastrophe as the most important contribution. In contrast with most fission products, almost all actinides (which are produced via neutron capture reactions) are rather long lived and can be measured in environmental samples with high precision. Some of the actinides (i.e., U, Pu, Cm) consist of various isotopes (e.g., 238,239,240,241Pu) and hence can be used to distinguish between soil contamination from different emission sources. Approaches are therefore presented for calculating the different fractions of contaminants by use of characteristic isotopic signatures.
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Energy, Waste and the Environment: a Geochemical Perspective
This book provides incentives for further development of sustainable fuel cycles through a novel and interdisciplinary approach to an Earth science-related topic. The main focus is on geochemical concepts in immobilizing, isolating or neutralizing waste derived from energy production and consumption. The book also addresses the issue of using some types of energy-derived waste as alternative raw materials. Moreover, it highlights research on how certain wastes can be used for energy production, an increasingly important aspect of modern integrated waste management strategies. The main objectives are to: (a) identify the most serious environmental problems related to various types of power generation and associated waste accumulation; (b) present strategies, based on natural analogue materials, for the immobilization of toxic and radioactive waste components through mineralogical barriers; (c) discuss modern procedures for reuse of waste or certain waste components; and (d) review the importance of geochemical modelling in describing and predicting the interaction between waste and the environment.