Maybe time for some of the doomsayers to put up or shut up? The following articles prove most of the doomsayers information on here is nonsense. The only issue is aviation and scalability for road transport. I think we can finally put a lot of this to rest.
Here are the basic facts.
1. In 1983, uranium cost $40 per pound. The known uranium reserves at that price would suffice for light water reactors for a few tens of years. Since then more rich uranium deposits have been discovered including a very big one in Canada. At $40 per pound, uranium contributes about 0.2 cents per kwh to the cost of electricity. (Electricity retails between 5 cents and 10 cents per kwh in the U.S.)
2. Breeder reactors use uranium more than 100 times as efficiently as the current light water reactors. Hence much more expensive uranium can be used. At $1,000 per pound, uranium would contribute only 0.03 cents per kwh, i.e. less than one percent of the cost of electricity. At that price, the fuel cost would correspond to gasoline priced at half a cent per gallon.
3. How much uranium is available at $1,000 per pound?
There is plenty in the Conway granites of New England and in shales in Tennessee, but Cohen decided to concentrate on uranium extracted from seawater - presumably in order to keep the calculations simple and certain. Cohen (see the references in his article) considers it certain that uranium can be extracted from seawater at less than $1000 per pound and considers $200-400 per pound the best estimate.
In terms of fuel cost per million BTU, he gives (uranium at $400 per pound 1.1 cents , coal $1.25, OPEC oil $5.70, natural gas $3-4.)
4. How much uranium is there in seawater?
Seawater contains 3.3x10^(-9) (3.3 parts per billion) of uranium, so the 1.4x10^18 tonne of seawater contains 4.6x10^9 tonne of uranium. All the world's electricity usage, 650GWe could therefore be supplied by the uranium in seawater for 7 million years.
5. However, rivers bring more uranium into the sea all the time, in fact 3.2x10^4 tonne per year.
6. Cohen calculates that we could take 16,000 tonne per year of uranium from seawater, which would supply 25 times the world's present electricity usage and twice the world's present total energy consumption. He argues that given the geological cycles of erosion, subduction and uplift, the supply would last for 5 billion years with a withdrawal rate of 6,500 tonne per year. The crust contains 6.5x10^13 tonne of uranium.
7. He comments that lasting 5 billion years, i.e. longer than the sun will support life on earth, should cause uranium to be considered a renewable resource.
8. Here's a Japanese site discussing extracting uranium from seawater.
http://www-formal.stanford.edu/jmc/progress/cohen.html
Paul Weisz's article on long−term energy supplies (Physics Today, July 2004, page 47) states that uranium resources with breeder reactors could provide the world's energy needs for "hundreds of years." That is a gross underestimate. The world's energy needs could be provided by uranium−fueled breeder reactors for the full billion years that life on Earth will be sustainable, without the price of electricity increasing by more than a small fraction of 1% due to raw fuel costs.1
The error in Weisz's calculation is that he is referring to uranium available at its present price, $10−20 per pound. But in breeder reactors, 100 times as much energy is derived from a pound of uranium as in present−day light water reactors, so we could afford to use uranium that is 100 times as expensive.
The cost of extracting uranium from its most plentiful source, seawater, is about $250 per pound—the energy equivalent of gasoline at 0.13 cent per gallon! The uranium now in the oceans could provide the world's current electricity usage for 7 million years. But seawater uranium levels are constantly being replenished, by rivers that carry uranium dissolved out of rock, at a rate sufficient to provide 20 times the world's current total electricity usage. In view of the geological cycles of erosion, subduction, and land uplift, this process could continue for a billion years with no appreciable reduction of the uranium concentration in seawater and hence no increase in extraction costs.
Reference
1. B. L. Cohen, Am. J. Phys. 51, 75 (1983).
Bernard L. Cohen
(
[email protected])
University of Pittsburgh
Pittsburgh, Pennsylvania
http://www.physicstoday.org/vol-57/iss-11/p12.html
The Sustainability of Mineral Resources
(exposition and illustration)
It is commonly asserted that because "the resources of the earth are finite", therefore we must face some day of reckoning, and will need to plan for "negative growth". All this, it is pointed out, is because these resources are being consumed at an increasing rate to support our western lifestyle and to cater for the increasing demands of developing nations. The assertion that we are likely to run out of resources is a re-run of the "Limits to Growth" argument (1) fashionable in the early 1970s, which was substantially disowned by its originators, the Club of Rome, subsequently. It also echoes similar concerns raised by economists in the 1930s, and by Malthus at the end of the 18th Century.
In recent years there has been persistent misunderstanding and misrepresentation of the abundance of mineral resources, with the assertion that the world is in danger of actually running out of many mineral resources. While congenial to common sense, it lacks empirical support in the trend of practically mineral commodity prices over the long term.
An anecdote brings this home: In 1980 two eminent professors, fierce critics of one another, made a bet regarding the real market price of five metal commodities over the next decade. Paul Ehrlich, a world-famous ecologist, bet that because the world was exceeding its carrying capacity, food and commodities would start to run out in the 1980s and prices in real terms would therefore rise. Julian Simon, an economist, said that resources were effectively so abundant, and becoming effectively more so, that prices would fall in real terms. He invited Ehrlich to nominate which commodities would be used to test the matter, and they settled on these (chrome, copper, nickel, tin and tungsten). In 1990 Ehrlich paid up - all the prices had fallen.
Of course the resources of the earth are indeed finite, but three observations need to be made: first, the limits of the supply of resources are so far away that the truism has no practical meaning. Second, many of the resources concerned are either renewable or recyclable (energy minerals and zinc are the main exceptions, though the recycling potential of many materials is limited in practice by the energy and other costs involved). Third, available reserves of 'non-renewable' resources are constantly being renewed, mostly faster than they are used.
http://www.uic.com.au/nip75.htm