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| Fig. 1: Country percentages of uranium mining production. (From Table 19 of [2].) |
Uranium is a radioactive metallic element that is used as the fuel source in nuclear bombs and reactors. Because the world, as of 2007 statistics, uses nuclear power to fulfill about 14% of its electricity requirements, uranium is a very important resource in the contemporary energy economy. [1] A discussion of current and future uranium supplies is thus relevant to how the United States and the other countries will respond to increasingly limited energy resources in the future. There are two main questions to consider when examining the world's supply of uranium: where does it come and how long will it last.
Uranium is naturally found in soil, rock, and water. Because it is quickly oxidized, it is found in nature in the form of U3O8, "yellowcake," or UO2, "pitchblende," rather than its pure metallic form. The first step of uranium production for military and commercial uses is thus the extraction of these uranium oxides from the natural environment.
The most common form of uranium extraction is open-pit and underground mining followed by uranium milling processing. As of 2007, 61.4% of the world's uranium production came from open-pit and underground mines. [2] Uranium producing countries are thus those with large amounts of minable uranium deposits. These countries include Canada, Australia, Kazakhstan, the United States, and Niger among others. The 2007 world distribution of uranium production is presented in Fig 1.
Currently the production of uranium has left a considerable gap between demand and supply. As of 2006, total uranium production only satisfied about 60% of the world's demand with about 39,600 tonnes (1 tonne = 1 metric ton = 1.1 ton) of uranium produced and 66,500 tonnes consumed. [2] For the United States, only about half the uranium demand came from production. Since 1993 the United States has engaged in a "Megatons to Megawatts" program with Russia to dismantle former highly enriched grade uranium warheads for energy usage. By the time of this program’s expiration in 2013, the U.S. will have used about 500 tonnes of former Soviet warhead uranium. [3] Other secondary sources of uranium include reprocessed uranium from spent reactor fuels and re-enriched uranium from depleted uranium tails.
To supplement the production-consumption gap, uranium production is projected to increase significantly within the next six years. By 2015, projected production expansion from countries such as Canada, Australia, and Russia is expected to increase total potential uranium production volume to 117,000 tonnes per year. [2] Projected increases are plotted in Fig 2.
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Fig. 2: Prospective uranium production
capability over time. [2] 
Production capability of existing and committed uranium
production centers at $80/kg. 
Production capability of existing, committed, planned and
propspective uranium production centers recoverable at $80/kg.
(From Table 24 of [2].) |
The prospective uranium resources are divided into categories describing the certainty and difficulty of extracting the uranium from the ground. There are "Identified Resources" and "Undiscovered Resources." Identified Resources are relatively confident estimates of uranium deposits from direct measurements and feasibility studies. “Undiscovered Resources” are resource estimates that fit well with already discovered deposits and previous geological and mining knowledge but with which there may not be direct evidence. [2] To examine long-term uranium supplies, we must look to these resource estimates and past the short-term lifetime of inventories and stocks that are currently filling the gap in production and demand.
As mentioned earlier, the world consumes about 66,500 tonnes of uranium a year. Uranium from Identified Resources account for about 5.5 million metric tones, while the remaining Undiscovered Resources go to about 10.5 million tonnes [4]. In terms of minable resource we thus have about 16 million/66,500 = 240.6 years of uranium at current usage. Demand usages are projected to increase to between 93,000 and 122,000 tonnes per year by 2030. [4] Assuming we hold at a constant 70,000 tons per year until 2030, where we then switch to 93,000, we will have as a best case scenario:
Thus we will only have about 180 years left of uranium. If nuclear energy was to account for all electricity produced, even if we only consumed 6.65 x 104 tonnes per year, then the case would be even grimmer. We would have only 240 x 0.14 = 33.6 years. Thus, if the world was to switch all of its electricity production to nuclear reactors, uranium would run out in a generation!
It is clear that current uranium resources are being used on a limited timeline. With current extraction and usage techniques, global uranium supplies will only be able to last on the order of 200 more years at current usage. With concerns about similar limitations on fossil fuels, changes must be made to the paradigm of energy production and consumption before countries are left scavenging for meager amounts of energy resources. Methods of enhancing the lifetime of nuclear energy, such as using more breeder reactors, improving enrichment technology, and potentially extracting uranium from seawater will have to be considered to delay the exhaustion of uranium. Undoubtedly, world uranium supply will be an increasingly important issue in the coming years with serious technological, economic, and political ramifications.
© 2009 Eric Landau. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] "Key World Energy Statistics, International Energy Agency, 2009).
[2] "Uranium 2007: Resources, Production and Demand," Nuclear Energy Agency, NEA No. 6345 (OECD Press, 2008).
[3] P. Podvig, "The Fallacy of the Megatons to Megawatts Program," Bull. Atom. Sci., 23 Jul 08.
[4] S. Fetter, "How Long Will the World's Supply of Uranium Last," Scientific American, 9 Mar 09.