Environmental Chemistry of the Transuranium Elements

TABLE 15.4 Events Leading to Large Injections of Radionuclides into the Atmosphere 

Source Country Time Radioactivity (Bq) Important Nuclides 

Source From G. Choppin, J. O. Liljinzin, and J. Rydberg, Radiochemistry and Nuclear Chemistry, Pergamon, London, 1994. 

Despite the extremely low concentrations of the transuranium elements in water, most of the environmental chemistry of these elements has been focused on their behavior in the aquatic environment. One notes that the neutrality of natural water (pH = 5-9) results in extensive hydrolysis of the highly charged ions except for Pu(V) and a very low solubility. In addition, natural waters contain organics as well as micro- and macroscopic concentrations of various inorganic species such as metals and anions that can compete with, complex, or react with the transuranium species. The final concentrations of the actinide elements in the environment are thus the result of a complex set of competing chemical reactions such as hydrolysis, complexation, redox reactions, and colloid formation. As a consequence, the aqueous environmental chemistry of the transuranium elements is significantly different from their ordinary solution chemistry in the laboratory. 

In natural waters, hydrolysis is the primary factor affecting concentration. The tendency to hydrolyze follows the relative effective charge of the ions. This is known to be 

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We simply define radiochemistry and nuclear chemistry by the content of this book, which is primarily written for chemists. The content contains fimdamental chapters followed by those devoted to applications. Each chapter ends with a section of exercises (with answers) and literature references. An historic introduction (Ch. 1) leads to chapters on stable isotopes and isotope separation, on unstable isotopes and radioactivity, and on radionuclides in nature (Ch. 2-5). Nuclear radiation - emission, absorbance, chemical effects radiation chemistry), detection and uses - is covered in four chapters (Ch. 6-9). This is followed by several chapters on elementary particles, nuclear structure, nuclear reactions and the production of new atoms (radio-nuclides of known elements as well as the transuranium ones) in the laboratory and in cosmos (Ch. 10-17). Before the four final chapters on nuclear energy and its environmental effects (Ch. 19-22), we have inserted a chapter on radiation biology and radiation protection (Ch. 18). Chapter 18 thus ends the fimdam tal part of radiochemistry it is essential to all students who want to use radionuclides in scientific research. By this arrangement, the book is subdivided into 3 parts fundamental ladiochemistry, nuclear reactions, and applied nuclear energy. We hope that this shall satisfy teachers with differrat educational goals. 

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