Plutonium occurrence

Aston, S.R., Assinder, DJ., Stanners, D.A. Rae, J.E. (1981) Plutonium occurrence and phase distribution in sediments of the Wyre estuary, north-west England. Marine Pollution Bulletin 12, 308-14. 

Many artificial (likely radioactive) isotopes can be created through nuclear reactions. Radioactive isotopes of iodine are used in medicine, while isotopes of plutonium are used in making atomic bombs. In many analytical applications, the ratio of occurrence of the isotopes is important. For example, it may be important to know the exact ratio of the abundances (relative amounts) of the isotopes 1, 2, and 3 in hydrogen. Such knowledge can be obtained through a mass spectrometric measurement of the isotope abundance ratio. 

Disproportionation of Pu(IV). There are several needs associated witn the occurrence, detection, and mitigation of the disproportionation of Pu(IV) in applied plutonium recovery/ purification procedures. First, there is a great need for much more detailed information concerning the effect of typical process conditions [e.g., temperature, concentration of plutonium, hydrogen ion, nitrate ion, nitrite ion, fluoride ion, other metal ions (e.g., A13+, Fe3+, etc.), etc.] on the occurrence and extent of the reaction ... 

Bros, R., Turpin, L., Gauthier-Lafaye, F., Holliger, P., Stille, P. 1993. Occurrence of naturally enriched (super 235) U implications for plutonium behaviour in natural environments. Geochimica et Cosmochimica Acta, 57, 1351-1356. 

Wahlgren, M A., Alberts, J.J., Orlandini, KA. and Kucera, E.T. (1977) Study of the occurrence of multiple oxidation states of plutonium in natural water systems. Argonne National Laboratory, Chicago. Annual Report ANL 77-65 Pt III, pp. 92-94. 

The occurrence of fission in uranium is due to the presence of 2llU, which makes up only 0.07% of natural uranium. Other elements including thorium, protactinium, neptunium, and plutonium are also capable of undergoing fission, and fission may be induced not only by neutrons but also by protons, deutrons, alpha particles, and even gamma rays. 

The known structures of the lanthanide and actinide metals are indicated in table 5.01, from which it will be seen that the structures characteristic of the true metals, and particularly the hexagonal close-packed arrangement, are common. Polymorphism, however, is of frequent occurrence among these elements, and plutonium, for example, crystallizes in no fewer than six modifications—the A1 and A2 structures indicated and four others of greater complexity. Praseodymium, neodymium and samarium are of interest in that they possess close-packed structures in which the sequence of layers is... 

The terrestrial occurrence of Ac, Pa, U, and Th is due to the half-lives of the isotopes 235U, 238U and 232Th which are sufficiently long to have enabled the species to persist since genesis. They are the sources of actinium and protactinium formed in the decay series and found in uranium and thorium ores. The half-lives of the most stable isotopes of the trans-uranium elements are such that any primordial amounts of these elements appear to have disappeared long ago. However, neptunium and plutonium have been isolated in traces from uranium13 minerals in which they are formed continuously by neutron reactions such as... 

Mild to severe chronic nephritis was observed in Sprague-Dawley rats following a single intraperitoneal injection of 2x10 pCi (7.4x10 Bq) plutonium-239 dioxide (Sanders 1973a). However, the statistical significance of these renal effects could not be determined based on the reported data. In addition, renal nephritis may be a common occurrence in the strain of rats used in this study. 

The order of reaction has an impact on the way of determining the time at which the reaction takes place, or conversely the degree of incident reaction at the time. The half-life of a reaction describes the time needed for half of the reactant to be depleted (think plutonium half-life in nuclear physics, which can be defined as a first-order reaction). In the case of reactions occurring during the flow, the degree of occurrence of the reaction depends on the speed of reaction and the way that the reactants have to proceed. Adequate factors (powers) of the Eq. 2.43 determined experimentally for selected reactions are given in Appendix A. 

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