Where is Uranium Found and How it is Processed for Nuclear Energy
Uranium, the raw material for today's nuclear fuel, is a slightly radioactive metal that occurs throughout the earth's crust. It must be processed through a series of steps to safely produce efficient fuel for generating electricity. Aerial view of the Ranger uranium mine, Northern Territory, Australia, 2014. Photo Credit M. Ingrames Uranium is about 500 times more abundant than gold and about as common as tin. Most rocks and soils, as well as many rivers and sea water, contain uranium. The largest currently known resources of uranium ore are in Australia, Canada and Kazakhstan. Uranium ore can come from mining directly for uranium, or as a by-product from mining minerals such as copper, phosphate or gold. The concentration of uranium in the ore could be from 0.03% up to 20%. The Talvivaara project is preparing to produce uranium as a by-product of the Talvivaara nickel mine in eastern Finland. Photo Credit Talvivaara Mining CompanyIdentifying and extracting uranium resources can be a challenge, especially in areas that have not been previously investigated. Excavating a large trench as part of an assessment of a uranium deposit for a possible future mining site in Central Jordan. Photo Credit P. Woods / IAEA Like other minerals, uranium can be extracted from open pit mines. The Roesing uranium mine in Namibia, seen here in 2012, is currently the world's largest open pit uranium mine in terms of volume. Photo Credit P. Woods / IAEAThis 2012 photo shows the second open pit at the Ranger uranium mine, Northern Territory, Australia, with the mill in the background. This mine has been in operation for over 30 years. Photo Credit P. Woods / IAEAAnother conventional method of mining uranium is by underground mining, which was the main method for producing uranium until 2009. Shown here is one of the mine entrances at the Rozna underground uranium mine, in the Czech Republic in September 2012. The mined uranium ore is crushed and chemically treated to separate the uranium, usually by the addition of acid or alkali. The remaining crushed rock, called 'tailings', must be appropriately and safely disposed in a secure manner to protect the public and environment. Photo Credit D. Calma / IAEAMilling is generally carried out close to a uranium mine. Uranium ore is crushed and chemically treated to separate the uranium. Shown here is a mill at the Roesing uranium mine in Namibia, 2012. Photo Credit P. Woods / IAEAHowever, the leading method to produce uranium today is by leaching it directly from the ore without mining, in a process called In Situ Leaching (ISL). The WNA (World Nuclear Association) reports that ISL mining accounted for approximately 45% of world production for 2012. In ISL, acidic or alkaline mining solution is passed directly through the underground ore body via a series of bores or wells and uranium is brought to the surface in a dissolved state for purification. No tailings are produced by this method. (The processing plant of the Alta Mesa in situ leaching uranium mine in Texas, USA, as seen from the nearby public road, 2008). Photo Credit P. Woods / IAEAShown here are extraction and injections wells and a well house at the Beverley in situ leaching uranium mine, South Australia. Uranium-rich solution is pumped to a central processing facility for further capture, purification and drumming. This solution is adjusted for the right chemical composition and pumped back to the wells to continue the process. Photo Credit P. Woods / IAEAThe result is uranium ore concentrate, 'yellow cake', an often but not always yellow powder of uranium oxide, peroxide or similar. In the yellow cake, the uranium concentration has been raised to more than 75%. Seen here is yellow cake coming off a conveyor line in a uranium mill. Photo Credit ArevaThe uranium ore concentrate is shipped from the mill to a conversion facility in order to be converted into fuel. Here, drums of uranium ore concentrate from the Rozna uranium mine in the Czech Republic await shipment. Photo Credit D. Calma / IAEA Current uranium mining and production uses high-tech systems and automation in all stages of operation. This reduces deployment of personnel in different areas. Seen here is the control room in Key Lake ore processing facility of Areva in Canada. Photo Credit H. Tulsidas / IAEAThe IAEA has long been involved in setting safety standards, as well as providing guidelines and advice to foster sustainable uranium production cycle activities. It also organizes a number of training courses and workshops every year to develop Member States' capacity in applying good practices in the uranium production cycle. In 2013, some 250 experts from 35 countries were trained in uranium geology, exploration, mining and processing through various courses and workshops held in Chile, the Democratic Republic of the Congo, India, Malawi, Tunisia and Zambia. Here, uranium mining experts are shown undergoing training in Langer Heinrich Uranium Mine in Namibia in November 2012. Photo Credit H. Tulsidas / IAEAThe Uranium Production Cycle Appraisal Team (UPSAT), an international peer review of uranium production sites and facilities provided by the IAEA, enhances the operational performance and the occupational, public and environmental health and safety of the uranium production cycle. The Mkuju River mining project is located on the edge of the Selous Game Reserve, a World Heritage Site, in the southern part of Tanzania. It was one of the projects reviewed by UPSAT in May-June, 2013. Photo Credit H. Tulsidas / IAEA
