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Fusion Plasma Plant in The Future
NightWulf writes "The BBC reports that Europe and Japan are currently looking to host a new JET power plant. This new plant creates plasma, which is akin to creating a star on Earth. Interesting to note that 1kg of fusion fuel would produce the same amount of energy as 10,000,000kg of fossil fuels."
One kilogram of fusion fuel would produce the same amount of energy as 10,000,000 kg of fossil fuel.
How much energy do they estimate it will take to create (and control?) that one kilogram of "fusion fuel"?
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...is how much energy it will take to maintain that 100 million degrees Celcius temp for 500 seconds or longer. Sure, 500 megatwatts sounds awesome, but fusion reactions are historically extremely difficult to maintain as the plasma constantly bumps into the container and kills efficiency. That being said, more research into the field is a Good Thing(TM).
Wikipedia has a solid list of the containment types. This helps illustrate way it's just so hard to keep the reaction going.
"The most advanced test reactors, the Tokomak Fusion Test Reactor (TFTR) in the U.S. and the Joint European Torus (JET), use the tokomak design and have come close to break even conditions. In fact, in November, 1991, the British-based Tokomak reported break even conditions. This occurs when the energy given off by the fusion reaction is equal to the energy input required to sustain the reaction. In order for a fusion reaction to generate useful amounts of electricity, the energy given off must be many times greater than that required to sustain the reaction. Even the most optimistic researchers feel that it will be well into the next century before this stage is reached." (from This site)
If they have to vent tritium (used in the reaction) and you are are you are near enough to breath it in you will be somewhere between deeply fscked and completely fscked. This is why everyone stays inside when they are running experiments :)
After the slashdot story a few weeks ago on the NASA Institute for Advanced Concepts (sorry, I'm too lazy to go look up the original Slashdot reference, but at least I'm honest about it), I started reading a lot of their proposals and most of the ones regarding how to handle interstellar travel involved anti-matter.
;-)
I started thinking about that and the two biggest problems with that are: A> It takes a huge amount of energy to create anti-matter, a hell of a lot more goes into the production than comes from using it. B> We don't really have a system for containing significant amounts of anti-matter.
So I started thinking about alternative energy sources and one of them was fusion. Pound for pound, fusion produces about 1/27th of the energy of anti-matter (based on my naive calculations, so I may be way off) whereas other types of fuel are several orders of magnitude less efficient.
To me, that makes fusion a pretty good option. The only problems I have encountered so far with the idea are:
1: Fusion isn't quite ready for real applications, though by the time we're capable of sending an interstellar craft, I believe it will be.
2: For an interstellar journey, you'll need a power plant that can survive for no less than decades, if not centuries, without maintenance. That's a serious issue given the harsh environment it would be operating in.
I'm sure there are additional problems I haven't thought of yet, but I'm still thinking it might be a good option. Perhaps some sort of self-repairing reactor could be built to solve #2.
But another huge advantage of hydrogen is that you could collect fuel along the way using the Bussard Ramjet idea. You'd just need a way of separating out deuterium and tritium from the hydrogen that doesn't suffer from problem #2 as well, but it should be doable. As most here are probably aware, fuel mass is a serious issue for space travel.
Anyway, I think fusion has a great deal to offer in a number of ways. Maybe I ought to work on my NIAC proposal
Another way of stating what you have said is that plasma fusion requires intervention to sustain the reaction, whereas the current generation of fission based power plants require intervention to restrain the reaction.
Fission is a stable reaction, fusion is very unstable. The difficulty in sustaining fusion is due to the fact that it is so hard to sustain the conditions under which it will occur.
The implications for safety are obvious: current generation fission designs require all kinds of redundant safety systems to prevent an ongoing and very dirty accident. Such systems would not be needed in a fusion reactor, becuase the least hiccup, such as weakening of magnetic containment or the leaking of tiny amounts of contaminants into the reactor would cause the reaction to collapse. There is no possibility of anything like the reactor catching fire driven by the heat of a runaway reaction.
That said, I'm skeptical we're going to see practical fusion in my lifetime, because it is so difficult to sustain, although you can always hope. A more promising technology would be a stable fission designs, that would require intervention to maintain fission, or which would only output heat at a limited rate.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
I'll add that the reason a star can sustain fusion is because of the immense gravity involved, it keeps the hydrogen (well, there are others, but those are later in a stars lifetime) compacted, and the force compressing them generates the heat needed for fusion.
As we can't create miniature stars at the moment, we have to compensate by supplying the heat and containment ourselves. One of the major barriers to a useful fusion reactor is getting it to produce more power than it draws.
Please don't paint all environmentalists with one big brush!
I like to consider myself a "green" kinda guy. I recycle, don't drive a SUV, etc. However, that said, bring on the nuclear power plants (provided we can properly secure them from whoever may want to crash a small plane into them... another story tho). Nuclear power is much cleaner than coal power, and the waste, while icky, isn't produced in huge quantities.
Some environmentalists will agree with me, some will disagree. But don't paint everyone with the same label. That'd be like me saying that most republicans are christian conservatives who want to turn the United States into a Christian version of Iran.
See how annoying that is?
Estimates for remaining Helium supplies suggest we may run out in about 20 years. Here's a little more for those who don't know as much about Helium as CodeMonkey.
Taken from here:
For most of this century the world's precious supply of helium has escaped from natural gas wells into the air. Only in 1958 did politicians heed the warnings of influential scientists including John Bardeen, the inventor of the transistor, that all our helium would be gone by 1980. Congress reacted by spending $1 billion--an astonishing sum in the 1950s--on a separation plant in Amarillo, Texas, and began stockpiling helium in empty gas wells.
As it happened, helium turned out to be crucial to the success of NASA's space--programme. The most powerful rocket motors are fueled by hydrogen and oxygen, both of which have to be carried in liquid form, and helium is the ideal refrigerant. In fact, it was helium carried to the Moon on the Apollo spacecraft that determined how long the astronauts could stay on the lunar surface. Once the helium had boiled off it would have been impossible to keep hydrogen and oxygen in liquid form and the spacecraft would have been stranded.
Thanks to the conservation measures, helium supplies were not exhausted by 1980. and other rich sources of the gas were discovered. however, sources of helium have remained few and far between because the geology of natural gas wells must be very special in order to hold onto it in commercial quantities.
Against this background, the worldwide consumption of helium has increased by between 5 and 10 percent a year in the past decade, which the biggest growth in its use as a coolant for the superconducting magnets in magnetic resonance imaging (MRI) body scanners. Present helium consumption is estimated to be about 100 million cubic metres, and is predicted to continue rising by 4 to 5 percent a year.
No one is claiming that we are in imminent danger of running out of helium--there should be at least 20 years supply left. However, new sources of the gas will have to be found to meet the ever-growing demand. If not, God forbid, we may have to celebrate helium's 200th birthday in the year 2095--without any Mickey Mouse balloons.
Aide-toi, le Ciel t'aidera - Jeanne D'Arc.
"As one of last season's Penn & Teller's Bullshit pointed out, the environmental movement is being highjacked by anti-corporate groups."
Exactly. If you look at something like the Clinton EPA new source review regulations, which punished corporations for more efficient energy production, and which environmentalists defend passionately, then its hard to reach any conclusion but that envnironmentalists are now pursuing an environmentally reckless anti-corporate agenda. As a result, there is new demand for legitimate environmentalism. This demand has spawned a conservative environmentalist movement. Among the tenets of conservative environmentalism:
- If the government internalizes externalities by imposing fees for despoiling or consuming public goods (air, water) then this eliminates the "tragedy of the commons" problem and incentivizes business to reduce environmental impact. When resources cost money, the market will favor business which produce the most efficiently, that is, the most output for the least monetary (and therefore environmental) cost. The key idea here is that no government regulations are required. You don't need regulators in the EPA to approve powerplant designs. Just license for the right to pollute, measure the output and enforce the law, and the market works to develop and choose new technology to reduce the overall level of pollution. Liberal environmentalists oppose this plan. Sierra Club and other groups lobby against tradable pollution credits because they "give corporations a license to pollute." But that's just not true. They are selling, not giving, corporations a license to pollute. The selling part is the crucial aspect.
- The primary goal of environmentalism should be to preserve and expand the land area of natural habitat. Liberal environmentalism, on the other hand, has set a whole bunch of additonal goals, such as advancing renewable energy resources, opposing fission, regulating private land use and regulating genetic diversity. These other actually work against expanding natural habitat.
- Reneable energy resources are anti-environmental because they have low-energy density; They take up too much space, displacing natural habitat. Ethanol fuel and solar power both require destruction of vast areas of natural habitat. The flux density of sunlight, collected either by crops or photovoltaics, is just too low to satisfy world energy demands without taking over a large surface area of the planet. The density of an energy source is the correct measure of environmental correctness. High density energy sources produce the most energy in the least space, displacing the least natural habitat. By this measure, petroleum is good. You only need about enough space to drill a hole in the ground and build a refinery. Fission has an even higher energy density. Geneticaly modified crops are good because they produce more food on less crop land, shrinking cropland and expaning natural habitat.
There are books about this stuff. I suggest "Hard Green: Saving the Environment from the Environmentalists". The phrasing is overstylized, manifesto screedish. Like a poor immitations of Abi Hoffman. (Though a more acurrate imitation would be worse). Nonetheless, IMHO its a fact-filled, well-reasoned argument.
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