Uranium production data

Payne, T.E. Waite, T.D. (1991) Surface com-plexation modeling of uranium sorption data obtained by isotopic exchange techniques. Radiochim. Acta 52-53 (Pt 2) 487-493 Peacock, M.A. (1942) On goethite and lepidocro-cite. Trans. Roy. Soc. Ca. 36 107-119 Peacock, S. Rimmer, D.L. (2000) The suitability of an iron oxide-rich gypsum by-product as a soil amendment. J. Environ. Qual. 29 1969-1975... 

Production of Uranium Oxides by Decomposition of Uranyl Nitrate (U02(N03)2) Aqueous Solutions. Based on data presented in Section 7.6.4, calculate the energy cost of production of uranium from uranyl nitrate in the plasma-chemical process (7-102). Compare the result with the energy cost of uranium production by direct plasma dissociation of uranium hexafluoride (see Section 7.4.2). 

Foreign. The OECD/NEA and IAEA have issued annual reports on world uranium resources, production, and demand since the mid-1960s (2—6). NEA/IAEA data for reasonably assured and estimated additional resources at costs of 80 and 130/kg uranium are given in Table 2 (21). These estimates incorporate data from both former world outside centrally planned economies (WOCA) and non-WOCA nations. A summary of other known uranium resources with and without cost range estimates is provided in Table 3 (22). These resources total about 1.4 x 10 t and include estimates that are not strictly consistent with standard NEA/IAEA definitions. 

These variations permit the separation of other components, if desired. Additional data on uranium, plutonium, and nitric acid distribution coefficients as a function of TBP concentration, solvent saturation, and salting strength are available (24,25). Algorithms have also been developed for the prediction of fission product distributions in the PUREX process (23). 

Hydroxides. The hydrolysis of uranium has been recendy reviewed (154,165,166), yet as noted in these compilations, studies are ongoing to continue identifying all of the numerous solution species and soHd phases. The very hard uranium(IV) ion hydrolyzes even in fairly strong acid (- 0.1 Af) and the hydrolysis is compHcated by the precipitation of insoluble hydroxides or oxides. There is reasonably good experimental evidence for the formation of the initial hydrolysis product, U(OH) " however, there is no direct evidence for other hydrolysis products such as U(OH) " 2> U(OH)" 2> U(OH)4 (or UO2 2H20). There are substantial amounts of data, particulady from solubiUty experiments, which are consistent with the neutral species U(OH)4 (154,167). It is unknown whether this species is monomeric or polymeric. A new study under reducing conditions in NaCl solution confirms its importance and reports that it is monomeric (168). 8olubihty studies indicate that the anionic species U(OH) , if it exists, is only of minor importance (169). There is limited evidence for polymeric species such as Ug(OH) " 25 (1 4). 

Although additional analyses of the existing data and additional experiments are required to reach definitive conclusions on the phase changes of ferrihydrite in uranium mine tailings, preliminary XRD data suggest that in deionized water at elevated pH (pH=10) phase transformation of ferrihydrite can occur at elevated temperatures. In both elevated temperature experiments, hematite appeared to be the dominant transformation product. At room temperature, however, ferrihydrite remains stable after the duration of the experiment (seven days). 

Act = 226.5 the naming of the parents follows the nomenclature employed by Fajans in which the element uranium is referred to as UrI. A place in the periodic table is then defined by a specific row and a specific column. From the data, one then readily obtains the row and column of each of the elemental daughters. Since the characterization of decay products emphasized the fact that many of these products are chemically indistinguishable from one another, it is of course expected that many of the places in the last two rows of the periodic table are occupied by more than one elementary material. What is surprising is that these chemically equivalent materials have different atomic weights, some differing by as much as eight units. 

Heat capacity data for ions in aqueous solution over the temperature range 25-200°C. Such data for ionic species of uranium, plutonium, other actinides and various fission products such as cesium, strontium, iodine, technetium, and others are of foremost interest. 

In a group of uranium mill workers, there was an excess of deaths from malignant disease of lymphatic and hematopoietic tissue data from animal experiments suggested that this excess may have resulted from irradiation of lymph nodes by thorium-230, a disintegration product of uranium. Some absorbed uranium is deposited in bone. A potential risk of radiation effects on bone marrow has been postulated, but extensive clinical studies on exposed workers have disclosed no hematologic abnormalities. ... 

Current U production is primarily from Canada (32% of world supply) and Australia (19%), as shown in Table 1 with data of the Uranium Information Centre (UIC 2003). Other U supplies are obtained through initiatives designed to reduce stockpiles of materials suitable for use in weapons. This includes the down-blending of weapons-grade uranium in the USA and Russia (UIC 2002). Uranium is... 

Although physics and chemistry were responsible for the conceptual framework overall, radiochemistry defined the experimental approach and provided much of the initial data. The neutron sources then in use (usually radium or radon [a source of alpha particles] mixed with powdered beryllium) were weak, with the result that the new beta activities were not much stronger than the natural radioactivity of uranium and its decay products. In 1934, the Rome group chemically separated the new activities from uranium by co-precipitating them with manganese and rhenium compounds (both transition metals), which supported the notion that these were... 

In another study of workers exposed to UF, the review of two years of follow-up medical data on 31 workers who had been exposed to uranium (VT) fluoride and its hydrolysis products following the accidental rupture of a 14-t shipping cylinder in early 1986 indicated that none of the 31 workers sustained any observable health effects from exposure to U even though an exposure limit of 9.6 mg was exceeded by eight of the workers (244). 

Extraction of Actinides(IV) and (VI). Table VI shows the D s for representative hexa- and tetravalent actinides from 3 M HNO3 at 50 C for DHDECMP, HHDECMP, and 0( )D[IB]CMPO. The same concentration of extractants in DEB were chosen as used to measure the fission product D s. The D for Np(V) was found to be 0.64 from 3 M HNO3 at 50°C using 0.5 M 0(j)D[IB]CMP0 in DEB. The data for U (VI), Np(IV), and Pu(IV) for DHDECMP are in general agreement but somewhat higher than the values reported by Schulz and Mclsaac (1). This disparity is probably due primarily to the lower purity of the CMP extractant used in the earlier work. The trends in distribution ratios for tetravalent actinides and uranium follow the same trends as D for the three classes of CMP extractants. 

At various facilities that process uranium for defense programs, uranium is released to the atmosphere under controlled conditions, resulting in deposition on the soil and surface waters. Monitoring data from the area surrounding the Fernald Environmental Management Project (formerly the Fernald Feed Materials Production Center) showed that soil contained uranium released from the facility (Stevenson and Hardy 1993). 

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