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The Coming Uranium Crisis
tcd004 writes "MIT reports that the world is running out of fuel for our nuclear reactors due to production limitations and an aging infrastructure. Nuclear power has gained popularity as a carbon-free energy source in recent years, but Dr. Thomas Neff, a research affiliate at MIT's Center for International Studies, warned that fuel scarcity could drive up prices and kill the industry before it gets back on its feet. Passport has pulled together some interesting numbers: there are 440 reactors currently in operation and 82 new plants under construction. The demand for fuel has driven the price of uranium up more than 40% in the last few months — 900% over the last decade. You can follow the spot price for a pound of uranium. "
Uranium prices have spiked in recent years, as TFA shows. However, comparing prices today with a decade or so back ignores the huge amount of uranium that hit the market after the collapse of the Soviet Union. A more honest comparison would go back several decades.
Another point to consider is that while current steam based nuclear power plants do burn uranium down to an unusable 'waste product', that waste is actually quite useful with reprocessing. So, while it is true that were the world only to burn low-level enriched uranium the world would run out quickly, it is not true that with a more modern burn-reclamation cycle that fuel shortages would persist.
But I think the point of fissile materials running out is set to be quite moot. Fusion reactor output has been increasing exponentially since its inception, and it should not be terribly long before it will be a viable alternative to fission power. Once we're set into fusion, it is basically impossible to run out of fuel. Fusion reactors run off of deuterium, which accounts for about 0.015% of all hydrogen. That is a crapload of deuterium! Consider that the oceans are 2/3 hydrogen (more or less) and heavy water is fairly easy to separate. (*actually, a tritium-deuterium reaction is more preferable for future reactors, but the tritium is refined from the deuterium--there is no natural abundance of tritium since it has a half life of ~17 years)
As a worst case scenario, we can always mine other planetary bodies. But despite the article's hype, don't expect us to run out of reactor fuel anytime this century.
When things get complex, multiply by the complex conjugate.
Err, that's an interesting thing to be taught; the core of the Earth is a sphere of liquid iron. Uranium isn't a siderophile (that is, it doesn't dissolve in liquid iron), so there won't be much uranium in the core (this also means there won't be much uranium in asteroids, in case space enthusiasts want to mention mining those for the uranium).
People have measured the uranium content of the inside of the Earth by looking for neutrinos of the right energy, which are produced during radioactive decay and fly straight through the Earth, and get that the quantity of uranium is enough to produce about 40 terawatts by radioactive decay. There is a crank theory that the core of the Earth has a fission reactor in it, but there's really very limited evidence for that.
Exam 4/C again. Maybe I'll do better this time.
Yes, it's depleted, but it's prefectly servicable fuel in a breeder reactor. A potential which rather makes me wonder how smart it is to spread it around in enemy territory. Gee, you wonder how smart that is? It's a pity the DOD didn't think to consult you before using DU as a projetile--- they probably never even thought about its potential as breeder reactor fuel!
Look, a breeder reactor isn't something two mujahideen can slap together out of adobe bricks in a weekend. It's safe to assume that anyone with the resources to build a breeder reactor can probably find something to put in it locally, they don't need to comb the Iraqi desert looking for 2lb bits of DU embedded 20' in the ground.
If a job's not worth doing, it's not worth doing right.
Folks, before you hop on a wishful bandwagon, how about making sure there is a wagon?
Breeder reactors reuse spent nuclear fuel. They only need small amounts of fuel to keep the reaction going. However, what about the waste? Compared to a conventional reactor, how much radioactive waste do they produce?
Since breeder reactors turn "spent" fuel into more usable fuel, they actually produce very little waste, and that waste has a very short half life. Breeder reactors are, in fact, both the answer to the fuel problem and the waste problem.If a job's not worth doing, it's not worth doing right.
Uranium is not dangerous, and one pound of uranium is not very much as far as power reactors are concerned. For reference, the density of uranium metal is 18 g/cm^3, so 1 lb of uranium metal would only be 25 cm^3 in size.
A typical PWR generates around 3000 MWt, runs for ~500 full power days, and is loaded with around 70,000 kg of uranium metal. So that is [3000 MW*500 d*24 hr/d*3600 s/hr]/[70 000 kg] = 1,851,429 MJ/kg. For comparison, gasoline contains 47 MJ/kg. Keep in mind though that the uranium metal is not really consumed, it is only depleted until it builds up too much neutron-absorbing fission products, at which point it can be reprocessed and reused.
If uranium metal is $80 per lb, then it costs a mere 2 cents for 1 GJ of thermal power. Gasoline costs about $3/gallon and one gallon weighs about 6.2 lbs=$0.48/lb. So gas is about $22.51 for 1 GJ, which is more then 1000 times more expensive then uranium.
It's no wonder we're running out, when most of the reactors in service around the world are grossly inefficient anyhow, and were practically designed to generate nuclear waste products they can't use for fuel. The typical light-water nuclear reactor today only exploits about 1% or less of the energy it can get out a given amount of nuclear fuel. (Assuming it has a once-through fuel cycle, which is the most popular.) Other technologies, however (such as the Integral Fast Reactor, which Hazel O'Leary and John Kerry so kindly helped to kill in 1994) which feature closed fuel cycles could theoretically safely use up to 95% of the energy stored in their fuel, and could in practice even consume the fuel-waste of other reactors. Other alternative fuel cycles feature materials such as Thorium as their fuel of choice. (Even Americium - the stuff in your smoke detector - has been considered as a fuel source.)
This 'Uranium Crisis' isn't caused by the mere consumption of nuclear fuel, but rather the ridiculously wasteful manner by which we've chosen to consume it for over half a century now. Better technology is within our reach that could allow us to dramatically stretch our nuclear fuel supply, both at current and greatly heightened consumption levels. While this hardly means we should stop worrying (good ideas too often fall before bad people) it does offer a bit of hope for us until nuclear fusion power finally takes off some time toward the end of our lives, if it ever does.
http://www.wise-uranium.org/upusa.html#SEAWATER
http://www-formal.stanford.edu/jmc/progress/cohen
http://en.wikipedia.org/wiki/Uranium#Resources_an
https://www.eff.org/https-everywhere