Some Uranium Basics

Uranium is found everywhere. It is in almost every rock and every ounce of seawater. Fission of one atom produces 10,000,000 times the amount of energy than the burning of one atom of coal.

Uranium is found everywhere.   It is in almost every rock and every ounce of seawater.  The chart below demonstrates this fact.

Very high grade ore

200,000 ppm

20%

High grade ore

20,000 ppm

2%

Low grade ore

1,000 ppm

0.1%

Very low grade

100 ppm

0.01%

Granite

4-5 ppm

0.0004% – 0.0005%

Earth’s continental crust (average)

2.8 ppm

0.00028%

Sedimentary rock

2 ppm

0.0002%

Seawater

0.003 ppm

0.0000003%

However, there are few areas that offer grade high enough or expansive low grade to be economic to mine.  Uranium, like most everything else that is mined, may be underground or open pit.  There is the question of radioactivity; however that comes into play with underground mines around the 4% mark.  In this case, robots mine the ore.

Most global uranium reserves are found in ten countries: Australia, Canada, Kazakhstan, South Africa, Brazil, Namibia, Uzbekistan, USA, Niger, and Russia.  Canada produces about 25-30% of world production and Australia about 23%.   Australia recently lifted is ordinance that only three producing uranium mines operating at the same time, however municipalities like Labrador, Canada, have moratoriums on uranium production.   The Athabasca basin in Saskatchewan and Alberta, Canada offers some of the highest concentrations – upwards to 20%. 

Uranium is a permeable element that is carried by water, and by doing so, often concentrates where water does, i.e. below lakes.  Hard rock mines do exist where U3O8 is, well, found in rocks and crushed, yet there are other types of mines like heap leach mines and in-situ mines (as well as the aforementioned underground and open-pit mines).  To digress, uranium is never mined in a pure form, rather concentrated as U3O8 (yellowcake). 

With this element found almost universally across the world, only about 62% of the requirements of power utilities are supplied by mines. Where does the remaining come from – one may actually thank the arms race of the 1980s.  There was a benefit of the Cold War, I guess.  Recycled materials from military nuclear programs and uranium in depleted uranium stockpiles, government inventories and recycled materials from prior use make up the difference.  Yet, the inventories are depleting and fortunately not too many WMDs were created. 

I have yet to address how much uranium is needed in a reactor, because that differs by plant.  However the average is about 75 tonnes of uranium fuel, and will change roughly 25 tonnes every refueling outage which is about every two years.  It should be noted that most nuclear reactors used enriched uranium, but not all.

Uranium fission produces 10 million (10,000,000) times the amount of energy than that of one atom of coal burned.  There are substitutes, plutonium and thorium, however plutonium is a man-made element (predominately a byproduct of nuclear fission with uranium) and the technology of thorium reactors is a ways away.  

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Comments

  • Ken

    May 21, 2010

    The ability to utilize Thorium in existing nuclear reactors is only a little way off at this point. Thorium Power, now Lightbridge, has been developing Thorium based fuels that dramatically reduce the long term radio-toxicity of the spent fuel and provides a means for utilizing Plutonium efficiently in light water reactors, in fact their design destroys Plutonium three times more efficiently than MOX.

    http://www.ltbridge.com/

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