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From uranium ore to fuel element: the front-end of the nuclear fuel cycle
Published in Peter R. Mounfield, World Nuclear Power, 2017
Uranium mining methods include open-pit as well as virtually all conventional underground techniques. Milling is essentially a leaching precipitation operation and the product is an oxide or salt concentrate containing 60–85 per cent U3O8 (uranium oxide) by weight. The basic steps are ore preparation, leaching and product recovery. The ore is first crushed and ground in wet rod-and-ball mills to produce a water slurry. Uranium is leached out of the slurry with acid or alkali depending on its nature, and the uranium solution is separated from the slurry to leave sandy waste residue (tailings). Uranium is extracted from the liquor by an ion exchange technique or by solvents. It is precipitated and collected on a rotary vacuum filter, dried in a kiln and calcined in a furnace to form the ore concentrate which because of its bright yellow colour is known as ‘yellow cake’. These processes are summarized in the flowsheet in Figure 7.8, but flows at particular mills may deviate somewhat from this generalized sequence according to the technology employed. The objective of all mills, however, is to produce the uranium concentrates which provide the feedstock for the subsequent processes that lead to the production of high purity uranium for fuel elements, and which are economically transported over long distances because of their high uranium content. Table 7.2 provides a summary view of the world’s uranium ore processing facilities, excluding the CMEA countries.
The Range of Environmental and Social Concerns
Published in Karlheinz Spitz, John Trudinger, Mining and the Environment, 2019
Karlheinz Spitz, John Trudinger
Today, uranium mining methods, tailings and run-off management and land rehabilitation are subject to strict government regulations and inspections (e.g. Australian Code of Practice and Safety Guide: Radiation Protection and Radioactive Waste Management in Mining and Mineral Processing 2005). Mining operations are undertaken under strict health standards for exposure to gamma radiation and radon gas. In fact a report by the Uranium Industry Framework Group argues that the level of regulation of the Australian uranium industry ‘may add to the perceived level of risk associated with uranium mining and perhaps hinders the public’s understanding of the actual level of risk’. That is to say, the public sees uranium mining as more hazardous than it really is.
Uranium Ore Mill Tailings Management
Published in James H. Saling, Audeen W. Fentiman, Radioactive Waste Management, 2018
James H. Saling, Audeen W. Fentiman
Uranium mining is the starting point for the nuclear fuel cycle. Uranium is widely distributed in the earth’s crust with an average abundance of about 2 g/ton. In general, uranium ore deposits considered suitable for mining contain 0.03–0.5% uranium by weight. Whether it is economical to mine a particular ore deposit depends on several factors including the richness of the ore, the market price for uranium, the mining technique used, and the associated health and environmental costs. Two methods have been commonly used for mining uranium ore: underground mines and open pit mines. Both techniques have been used historically to mine other ores or coal, and both are well understood. Another uranium mining method called in situ or solution mining has been tried on an experimental basis. Underground mining of uranium has associated with it all of the hazards of underground mining of other natural resources as well as elevated concentrations of radon gas, radon being a radioactive decay product in the uranium chain. Open pit mining requires moving large amounts of overburden to reach the ore body and then replacing the soil, an expensive process that can leave scars if the site is not properly reclaimed. Most of the uranium mined in the United States has come from open pit mines. The in situ mining involves pumping a solvent through the ore body in the ground and removing the uranium in solution. This method avoids the dangers associated with underground mining and the environmental damage done by open pit mining. However, it does not recover as much of the uranium present as the other two methods, and there are concerns about contaminating groundwater with the solvent.
Effects of uranium mining and milling on benthic invertebrate communities in the Athabasca Basin of Northern Saskatchewan
Published in Canadian Water Resources Journal / Revue canadienne des ressources hydriques, 2018
Bruce W. Kilgour, Barbara Dowsley, Malcolm McKee, Steve Mihok
Aquatic environments downstream of uranium mining and milling operations (hereafter mining) are exposed to a variety of both chemical and physical disturbances. The individual and combined effects of released contaminants on freshwater organisms have been tabulated in the gray literature, but have rarely been analyzed in the scientific literature (Peterson et al. 2002; Mihok and Thompson 2011) with the exception of selenium (Muscatello et al. 2008; Muscatello and Liber 2009; Wiramanden et al. 2010; Gallego-Gallegos et al. 2012; Tse et al. 2012; Franz et al. 2013). There is a wealth of underutilized data on benthic invertebrate community composition in this context from metal mines in Canada. There have, however, been no substantive peer-reviewed examinations of mine-related data exploring the influences of uranium mining on lake or stream benthic communities.
The concentration of radioisotopes (Potassium-40, Polonium-210, Radium-226, and Thorium-230) in fillet tissue carp fishes: A systematic review and probabilistic exposure assessment
Published in International Journal of Environmental Health Research, 2022
Peyman Ghajarbeygi, Vahid Ranaei, Zahra Pilevar, Amene Nematollahi, Sahebeh Ghanbari, Hajar Rahimi, Hoda Shirdast, Yadolah Fakhri, Trias Mahmudiono, Amin Mousavi Khaneghah
In most parts of the world, uranium mining is hazardous for the number of radiation doses and the numerous damages it causes to people (Skipperud et al. 2013). Uranium can enter the water, air, or soil due to its transportation in aquatic and terrestrial environments, transmitted to plants, fishes, animals, and humans. 210Pb, 210Po, and 226Ra are some of the important products of uranium (Skipperud et al. 2013). 210Po and 210Pb radioisotopes are known to be reactive in the marine environment. 210Po is absorbed by plankton and found in abundant organic particles, while 210Pb is absorbed by fine inorganic particles in seawater (Aközcan and Uğur 2013).