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Uranium is one of the most abundant elements found in the Earth's crust. |
In its pure form, uranium is a silvery white metal of very high density, more dense even than lead. Uranium can take many chemical forms, but in nature it is generally found as an oxide (in combination with oxygen). Triuranium octoxide (U3O8) is the most stable form of uranium oxide and is the form most commonly found in nature.
Where is Uranium found?
Uranium is one of the most abundant elements found in the Earth's crust. It can be found almost everywhere in soil and rock, in rivers and oceans. Traces of uranium are even found in food and human tissue. However, concentrated uranium ores are found in just a few places, usually in hard rock or sandstone.
The concentrations of uranium vary according to the substances it is mixed with and according to the places where it is found. For example, when uranium is mixed with granite that covers 60% of the Earth's crust, there are approximately four parts of uranium per million, i.e. 999,996 parts of granite and four parts of uranium.
| 200,000 ppm* U |
High-grade orebody - 20% U |
| 1,000 ppm U |
Low-grade orebody - 0.1% U |
| 4 ppm U |
Granite |
| 2 ppm U |
Sedimentary rock |
| 1.4 ppm U |
Average in Earth's continental crust |
| 0.003 ppm U |
Seawater |
| *ppm = parts per million |
Concentrations of uranium that are economic to mine are considered ore. Uranium is present in low concentrations in many rocks and bodies of water, but extraction is only economically viable from richer deposits. The decision to mine is a function of many factors including extraction method, market prices and social and environmental considerations.
Where are Uranium deposits located?
Uranium deposits are found all over the world. The largest deposits of uranium are found in Australia, Kazakhstan and Canada. High-grade deposits are only found in Canada. The following illustration shows known conventional resources of uranium.
Source: Uranium 2001: Resources, Production and Demand, OECD/IAEA. Based on known conventional resources which consist of reasonably assured resources plus category 1 estimated additional resources at costs less than $80(US) per kilogram U, as at January 1, 2001.
What is Yellowcake, Anyway?
Yellowcake |
Yellowcake is milled uranium oxide, known to chemists as U3O8. When uranium ore comes out of the mine, it actually contains fairly little of the precious radioactive element. Though some mines in Canada, the world's leading uranium producer, are now yielding ore that contains 20 percent uranium, lower purity levels are more typical. Ore that contains less than 1 percent uranium is not unusual.
The milling process gets rid of the useless minerals that dominate the ore. First, raw ore is passed through a series of industrial-sized crushers and grinders. The resulting "pulped" ore is then bathed in sulphuric acid, a process which leaches out the uranium. After some drying and filtering, the end product is yellowcake: a coarse, oxidized powder that is often yellow in color but can also have a red or gray tint, depending on the number and type of impurities that may remain. Ideally, a drum of yellowcake should wind up looking something like this.
Yellowcake is a first step toward enriched uranium, but it's a long way from being weapons-grade. The powder must still be converted into uranium hexafluoride before it can be enriched, the process that makes the sort of uranium used by nuclear power plants and bomb-makers alike. Because UF6 can be easily turned into a gas, it is ideal for enrichment, which must be done in a gaseous state.
Source : Brendan I. Koerner
The Global Energy Market
For both political and practical purposes, industrialized nations are increasingly focused on finding alternative energy sources to reduce their reliance on fossil fuels. Natural and geopolitical supply disruptions, global warming concerns, deregulation and price volatility are all contributing to accelerated technological exploration. Moreover, rising demand for power, especially from exploding economies like China and India, will put ever increasing pressure on the global energy supply chain. Even in the United States, demand is expected to grow by 50% by 2025, up from a whopping 3,831 billion kWh in 2002.
The resulting gaps in the global energy grid have prompted a re-visitation of Nuclear Power. One of the only emissions-free sources of electricity in wide use today, Nuclear Power is increasingly viewed, even by environmentalists, as the only practical, large-scale alternative to oil and gas. Nuclear power provided nearly 20% of the world's electricity generation in 2003, second only to coal.There were 440 nuclear powerplants in operation in 2003 in 30 countries which consumed 77,000 tonnes of Uranium (200 million pounds). Of the total Uranium consumed in 2003, however only about half came from operating mines, with the balance derived from secondary supply sources such as highly enriched uranium from dismantling nuclear weapons and inventory draw down.
However, 30 new plants are under construction and an additional 34 are in the planning stages. By 2020, however, dwindling secondary supply sources will cover only about 15 percent of Uranium demand, with the balance coming from newly mined and processed Uranium. Current and planned mines will not be adequate to supply the projected demand for primary Uranium supply - the need for these new supply sources is a foregone conclusion. Concern about where the Uranium will come from has been a factor in the rise of the Uranium price in the past several years.
Global Uranium Demand Outpaces Supply Production
In 2003, 77,000 tons of Uranium Oxide were consumed to produce 360,500 megawatts of power worldwide. The 64 reactors planned and under construction would produce an additional 60,000 Mwe. Already, Uranium consumption is outpacing mine production, and global inventories of Uranium stockpiled in the 1970s and 80s are nearing depletion. The cost of Uranium is so insignificant relative to the capital and operating costs of a Nuclear Reactor, that spot prices have climbed from a low of US$7.10 /lb. in late 2000, to recent 20-year highs of over US$138.00/lb. with no fall-off in current demand. Moreover, demand is projected to grow by 3% to 4% annually until 2012.
How do Nuclear Reactors compare to other Reactors?
All power plants, including nuclear, work pretty much alike. Basically, the fuel (whether that be coal, gas or uranium) heats water and turns it into steam. The steam turns the propeller-like blades of a giant turbine, which in turn drives the shaft of a huge generator. Inside the generator, coils of wire and magnetic fields interact, and electricity is produced.
The biggest difference between conventional power plants and Nuclear power plants is that nuclear power plants don't burn fossil fuels or anything else. Instead, they split uranium atoms. That means they don't create acid rain, soot, urban smog or carbon dioxide (the principal greenhouse gas). In OECD countries alone nuclear power plants avoid some 1,200 million tones of carbon dioxide emissions annually. Assuming that all nuclear power plants in the world were replaced by modern fossil-fuelled power plants, CO2 emissions from the world energy sector would rise by about 8%.
| Environmental Comparison |
Fuel Comparison |
Nuclear reactors are more fuel efficient than conventional reactors and are emissions free.
Uranium Pellet |
A typical pellet of uranium weighs 7 grams (.24 ounces). It can generate as much energy as 3.5 barrels of oil, 17,000 cubic feet of natural gas or 1,780 pounds of coal. The energy contained in one pound of yellowcake, or U3O8, is equivalent to 31 barrels of fuel oil, or 10 tons of coal, so the total energy produced from Wyoming Uranium is equivalent to 5.9 billion barrels of fuel oil or 1.9 billion tons of Wyoming coal.
Uranium is an extremely concentrated and efficient fuel, much more so than coal or oil. The following table shows the extent to which this is true:
| ENERGY SOURCE |
ELECTRICITY PRODUCED |
| 1 kg of firewood |
1 kwh (kilowatt hour) |
| 1 kg of coal |
3 kwh |
| 1 kg of oil |
4 kwh |
| 1 kg of Uranium |
50,000 kwh |
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