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U.S. and China Join Fusion Project
Garp writes "According to the BBC News website, the U.S. has finally decided to join the international Fusion project, Iter, along with China, with the aim of building the worlds first commercially viable Fusion reactor. Fusion is one of the cleanest forms of energy conversion, excluding renewable natural sources, like wind farms, tidal generators, and solar cells."
So who gets to set off the first fusion bomb?
Fusion has been the nuclear reaction in all the modern weapons. Typically, a fission reaction is used to initiate the much more powerful fusion reaction. The real trick is getting CONTROLLED, CONTAINED fusion to work. That problem is what fusion as a viable energy source is all about. Just getting atoms to fuse and produce tons of energy is no great feat.
GMD
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I suppose "cleanest" may be literally true, but in terms of overall environmental impact, fusion has got to easily whip at least the first two. The environmental footprint of windmills and tidal hydroelectric is huge. And, of course, most of the world doesn't have a tide to draw on, and I'm not even getting into the "draining the angular momentum of the planet" issue.
What I'm listening to now on Pandora...
I see from the Iter website that this reactor is essentially trying to get fusion to occur using the magnetic-confinement technique of the Tokamak reactor. The other approach to controlled fusion studyied over the last few decades is inertially-confined fusion. Can anyone tell us what the state of inertially-confined fusion is? Does the US's and China's joining of the Iter project signify that the mainstream thought is that inertially-confined fusion is dying? My understanding is that both were hot research topics in the 90s but I don't know what the current thinking is. Any help would be greatly appreciated.
GMD
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The hideously low efficiency of solar cells makes them a waste of -other- natural resources to manufacture, transport, purchase, install, and maintain.
That is, you burn more fossil fuel energy deploying photovoltaic arrays than you regain during their (short) usable lifetime. That doesn't make them any less-convenient for remote off-grid applications, but they're not going to replace other power sources anytime soon.
Solar energy is still viable for heating (obvious) as well as power generation using mirror concentrators.
Could you please back your statements up with some sort of facts, preferably from a reliable source?
This source seems to suggest otherwise. Btw, the mass-production of solar-cells has begun after the publishing of this paper.
>during their (short) usable lifetime
I don't know about your experience. But I've had a solar cell, which has been serving me well for longer than 20 years. Guarantees are usually issued for 20 years lifetime.
Interestingly, I've heard similar stories about nuclear plants. Not that I'm claiming that they are true.
"Between strong and weak, between rich and poor [...], it is freedom which oppresses and the law which sets free"
it may produce 500 megawatts of fusion power for 500 seconds or longer, but how much energy is required to initiate the process? i'm not really that familiar with fusion, but it would seem that quite a bit of energy would be required to heat the elements to the balmy 100 million Celsius.
While it is true that the result from Iter will be a lot of radioactive waste, this project must continue because it is vital to fusion research. The radioactive waste will result because of the plan to use stainless steel in the reactor construction. Stainless steel is easy to activate (because of the nickle and other elements in it) however it is one of the few materials that can take the reactor wall loading that we know how to work with (Vanadium would be an excellent replacement and have a very short halflife (on the order of decades) except for the fact nobody really knows how to roll it, weld it, make it into a pipe etc...). Don't forget that the vast majority of our industrial complex is built on the understaning of steel.
As with any prototype, there are issues. Fusion by itself is clean and if low activation materials can be used, such a silicon carbide and vanadium, which will result in very little radioactive waste with short halflifes.
The other aspect of ITER, which is a boon for fusion research, is that it is the first comercial "scale up" of a fusion reactor. Current research reactors are small and thus too small to generate enough fusion power to be useful on a grid. Fusion does occur, but it is not at a "density" (I am taking a bit of liberty with the nomenclature for a simplified explanation) that is sufficient to offset the power put into the system (ie other lossy effects are not overcome until there are more fusion reactions per unit time in a given volume)
In short future reactors will be a LOT cleaner after ITER. It's sort of like the early days of fission. A crude graphite pile lead to intrinsically safe and efficient boiling water reactors. It seems to me that a little bit of pain to jumpstart the research is worthwhile.
So we'd have fusion technology today if Joe Scmuchatelli had a weak inkling of what happens in a nuclear reactor? I'm afraid you're vastly uninformed about fusion. The problem isn't that Joe Sixpack doesn't know a little, the problem is that Joe Scientist doesn't know the intricacies of how to maintain a fusion reaction. That's why this facility is being built.
Fusion research has reached a stage where the only way to get closer to commercial production is to scale the whole experiment up. You state that there haven't been any experiments to show fusion can be used commercially... Well Duh! Researchers have only recently gotten past the break even point. That's why we call it "experiment", and not "commercial implementation". The problem is not one of not enough qualified workers and thus it's too expensive, the problem is we just don't know how to make a sustainable fusion reactor yet.
AccountKiller
They don't like to mention how many hundreds of tons of material would be made radioactive by the heavy neutron bombardment from hydrogen reactors.
Fusion reactors do not generate high level radioactive waste that must be isolated for geological lengths of time in the way fission reactors do. The radioactive by products from a fusion reactor are low level and with short half-lives (less than 100 years). The short half-life makes in place storage of the irradiated structural components quite feasible - they don't need to be transported etc.
In addition a fusion reactor is fail safe - there is no danger of a meltdown or similar event.
The real attraction of fusion is that it is potentially extremely scalable. Alternative energy sources like solar, wind, etc. are attractive within the near term framework of reducing greenhouse gases over the next decade or two. Ultimately however it is hard to imagine how these dilute, funtamentally limited sources of energy will supply what is needed for strong economic growth into the next century, or a world population that exceeds 10 billions.