Risky, we-can't-fail, all-or-nothing science
cbc.ca
cbc.ca
"Sometimes your research should be based not on how glorious success might be, but on how little you will have lost if you screw up."
Fair enough. But -- there should be outliers. Apollo. Hubble. Manhattan Project. Genome Project. There's a ton of small, incremental science being funded in the US. There should also be some big, ambitious science. Both approaches are valid and useful.
And this probably applies to startups as well.
On reading this I was doubting the value of the article. I shall continue . . .
edit: Later on there is also the following
The exhibit "tried to explain to people how the reactor would work, why it was a good thing (no radioactive waste left after the reaction, for one, and no greenhouse gases are produced) and why it was hard to do."
I'm getting out of my depth here but it was my understanding that thermal fusion releases large numbers of neutrons which lead to the containment vessel to slowly become radioactive. I would love to be corrected.
While the article is extremely interesting I find that costs and time periods for this kind of science are misrepresented. Not that $5 billion isn't a lot of money, but it is on par, if not lower than many other energy projects. The Alberta Tar Sands alone have had more than $30 billion invested in the past decade. It also does not come close to the investment originally made into fission power production and continually made to produce next generation reactors. Without 'risky science' we don't move forward. Our efficiency may increase; a better stone for making axes means a tree can be cut faster, but by making great leaps forward in science, we may no longer need the axe, or even the tree. The ITER, the LHC, the Manhattan Project, are (were) investments in our future and the future of science and understanding. While some of these projects may fail, the cost of not trying is far greater.
The difference is that there is no place in the market for fusion reactors. In light of the existing half-billion-year [Edit: half-trillion-year] fuel supply for fission reactors, the drive to create fusion reactors is nonsensical.
PS: I want fusion because long term they make for better spaceships but that's just me.
Edit: Breeder reactors unlike "normal" power plants can also blow up with about the same force as the same amount weight of TNT where fission power plants can't.
The energy density and potential output is far higher (theoretically) with fusion than with fission. You may also want to check your figures on the half a billion year fuel supply. At current rates of use, uranium fuels will last about 1000 years. Thorium is an alternative option for fission power; however, this is yet unproven in large scale deployment. There is also the fact that fusion reactors will produce far less high-level (long half-life) radioactive waste.
50 years ago, and even today, critics believed that there was no place for fission power but now it appears to be our greatest alternative to providing base load power over hydrocarbon based plants. The uses of fusion technology are not only limited to power production either. Fission power has resulted in advances in materials, medicine, the understanding of basic atomic science. There is no doubt that properly understanding fusion will lead to many advances in other fields.
Is that true by volume of fuel? By weight, the energy density is only 4 times as high (D-T) (http://en.wikipedia.org/wiki/Energy_density#Energy_density_i...). By volume, the density of uranium/thorium might very well be typically higher, since uranium/thorium is a heavy-metal, and therefore notably dense.
For convenient fuel storage, the deuterium and tritium might be temporarily be converted to water. I'm not going to do the math right now, but I think it would be interesting to see how that compares volumetrically to uranium/thorium energy density.
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Please clarify.
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There are more than 40 trillion tons of uranium in the earth's crust (mostly in the continents, and mostly near the surface of those continents):
http://nuclearinfo.net/Nuclearpower/UraniuamDistribution
The world currently uses ~60,000 tons per year of uranium. http://www.world-nuclear.org/info/reactors.html
~60,000 tons/year / 60x breeder-factor / 2.5x thermal-efficiency improvement = 400 tons/year fuel use. 40 trillion tons of uranium / 400 tons used/year = .1 trillion years of uranium.
Thorium is available in the crust at some 4 times the ubiquity of uranium = .4 trillion years of thorium.
Adding the uranium and thorium together gives us .5 trillion years of fission fuel.
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The higher output is a function of the higher energy density.
Your numbers may be correct about how much uranium there is in the earth's crust but you are missing two very important points. Only a tiny fraction of the uranium is in concentrated enough deposits to allow for economic recovery of the mineral. This and the fact that U-235, the fissile isotope of natural uranium, occurs in only 0.711% of uranium containing minerals leaves only enough uranium with reprocessing for the next 1000 years.
http://www.world-nuclear-news.org/ENF_Exploration_drives_ura...
Thorium required a breeder reactor in order to produce the U-233 necessary for fission, and as stated in another comment, these reactors are still in experimental stages and have a much lower level of operational safety record.
A thorium breeder is not the same thing as a uranium breeder.
Given that that very point was addressed at the link I provided, one might suspect that you did not visit it before answering.
It is not merely 40 trillion tons of uranium that are in the crust. It is 40 trillion of uranium that is also economically-recoverable. Why is nearly all of the uranium in the crust is economically-recoverable? It is because the energy density of uranium is so high. The same goes for thorium.
No, it doesn't.
http://www.google.com/search?q=site%3Ajuliansimon.com%2Fwrit...
Reserve definition
Reserve definition is undertaken to convert a mineral resource into an ore reserve, which is an economic asset. The process is similar to resource evaluation, except more intensive and technical, aimed at statistically quantifying the grade continuity and mass of ore.
Reserve definition also takes into account the milling and extractability characteristics of the ore, and generates bulk samples for metallurgical testwork, involving crushability, floatability and other ore recovery parameters.
Reserve definition includes geotechnical assessment and engineering studies of the rocks within and surrounding the deposit to determine the potential instabilities of proposed open pit or underground mining methods. This process may involve drilling diamond core samples to derive structural information on weaknesses within the rock mass such as faults, foliations, joints and shearing.
At the end of this process, a feasibility study is published, and the ore deposit may be either deemed uneconomic or economic.
http://www.world-nuclear.org/info/inf75.html
the finding costs of crude oil have averaged around US$ 6/bbl over at least the past three decades. When finding costs of the two fuels are expressed in terms of their contained energy value, oil, at US$ 1050/MJ of energy, is about 300 times more expensive to find than uranium, at US$ 3.4/MJ. Similarly, the proportion of current market prices that finding costs comprise are lower for uranium. Its finding costs make up only 2% of the recent spot price of US$ 30/lb ($78/kgU), while the oil finding costs are 12% of a recent spot price of US$ 50/bbl.
By these measures, uranium is a very inexpensive energy source to replenish, as society has accepted far higher energy replacement costs to sustain oil resources.
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Please reread the original article I linked to regarding the 1000 year supply. It actually deals with undiscovered reserves.
In addition to these identified resources, the category of uranium that could be expected to be found based on the geologic characteristics of known resources has grown by 500,000 tonnes to 10.5 million tonnes.
The data comes from Uranium 2007: Resources, Production and Demand - often known as the Red Book - published every two years by the OECD Nuclear Energy Agency (NEA) and the International Atomic Energy Agency (IAEA).
from: http://www.world-nuclear-news.org/ENF_Exploration_drives_ura...
The word "currently" is important here. It means that the statement containing the word is irrelevant in the long-term. Resource supply-size increases exponentially to linear increase in price. How high of a price increase can the market accept? The current uranium prices contribute about .2 cents per kWh of electricity produced.
http://www.world-nuclear.org/info/inf02.html
Multiplying the uranium price by 10 causes it to contribute only 2 cents to the cost of each kWh of electricity produced. That is before further fuel-efficiency advances are applied, which the higher fuel prices would incentivize.
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Where is your cutoff for economic seawater uranium mining?
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That would make it cost less than a penny per kWh. Are you meaning to suggest that the electricity market would not accept a fuel-price of under a penny per kWh?
Please keep your bigotries to yourself, and don't speak for what mine might be.
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That would be the total cost of the fuel after conversion, enrichment, and fabrication. The U3O8 cost of $472 is .264 of the total cost of $1787, which indeed works out to less than 0.2c/kWh (about 0.131c/kWh, actually) if $1787/kg of fabricated-fuel works out to 0.5c/kWh.
2007 fabricated-fuel costs at U.S. nuclear powerplants were 0.47c/kWh. http://www.nei.org/resourcesandstats/nuclear_statistics/cost...
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Please provide at least a single example of any math errors I might have made.
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Indeed, there might only remain some 70,000 years' worth of oil.
http://www.google.com/search?q=oil+70000+dabasteroid
Is there reason to believe otherwise?
Those are "identified resources", which means that they are irrelevant. There are 2 trillion tons (5 billion years' worth) of economically-recoverable uranium in granite, alone.
And did you really state that taking uranium out of granite is economical? The granite you want to mine is worth more than the uranium in it, not to mention that it would take more energy to mine it than you would get from it. There are only 3-10 part per million of uranium in granite.
Have you read this?:
http://nuclearinfo.net/Nuclearpower/UraniuamDistribution
The Rossing mine in Nambia mines Uranium at an Ore concentration of 300 ppm at an energy cost 500 times less than the energy it delivers with current thermal-spectrum reactors. If the energy cost increases in inverse proportion to the Ore concentration, shales and phosphates, with a Uranium abundance of 10 - 20 ppm, could be mined with an energy gain of 16 - 32.
Extrapolating from that, the energy gain is 1.6 for every ppm of uranium. As you say, granite contains 3-10 ppm of uranium. Therefore, mining granite for its uranium would provide an energy gain of 4.8 to 16. That would be without improving current reactor thermal-efficiency at all, and without improving current reactor breeding efficiency at all (all fission-reactors fueled with a mixture of U235 and U238 breed to some extent).
Running a uranium economy off of such a low-grade ore would, of course, in the real world provide incentive to improve fuel-efficiency (thermal; breeding-ratio; etc.) of reactors (even thermal-spectrum reactors can have their breeding-efficiencies improved). Thus, in the real world, the energy gain from mining granite for uranium would likely be higher than 4.8 to 16.
It's your link. I was quoting you and commenting on it.
That might have cleared everything up for me, except that I do not know what you mean by "higher output". Are you referring to power output? You are saying that, generally, in a given case of equal-sized reactors, a fusion reactor would be able to produce higher power than a fission reactor?
If I had disregarded that, how do you figure I got a 60x energy boost by applying fuel-breeding?
I took the article as a whole as suggesting that research into fusion on this scale is not a good thing, and it specifically quoted a critic as saying that fusion was desirable, but nobody knows how to contain it. Which suggests to me that the article is in accord with you on that subject.
So overall, I don't think the article is suggesting that fusion is good, or clean, but rather the article makes the point that fusion's supporters hope that in forty years or so we might have something that is good or clean.
...Which is an absurd thing for that critic to say when even fusion's proponents admit that even if it could be made to work, it would not likely be economically competitive.
Nobel laureate in physics Pierre-Gilles de Gennes is once supposed to have said about the problem of fusion power in general, "We say that we will put the sun into a box. The idea is pretty. The problem is, we don't know how to make the box."
I'm thinking that when a Nobel laureate in physics says that an idea is pretty, he is not suggesting that it is economically feasible or even workable. Nor is he saying that we should build it regardless, he is merely saying that it's an attractive idea, but technically impossible given what he knew when he said it.
Which is not the same thing as "Based on the known laws of physics this will never work."