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Japan's JT-60 Tokamak Sets New Plasma Record
Dipster writes "The Japan Atomic Energy Agency has announced that its JT-60 Tokamak has almost doubled the previous record for sustained plasma production, which is now sits at 28.6 seconds. It is believed that once 400 seconds can be achieved, a sustained nuclear fusion reaction will be possible. While 28.6 seconds is a long way from 400, it raises hopes for what will be possible from the ITER reactor, expected to be finished in 2016."
Movies have let me down. I was supposed to be flying around Mars on my Mr. Fusion powered space car 15 years ago.
I know its pretty unreasonable to ask "when is technology x coming out," but a rough order of magnitude (are we talking 10 years? 100?) has got to be doable."
Depends on how much money gets thrown at it. If ITER shows promise, and there's really no technical reason it shouldn't do what they expect, these projects will get more funding and it'll be a matter of decades. France and Japan will be along for the PR alone, which means China and the US will have play as well to save face. This could very well turn out to be the next Space Race. With ITER in 10 years, I'd guess commercial plants (likely government funded or subsidised) within 25. I expect to see it in my lifetime.
"Also, if we do get large scale fusion, is it really going to be cleaner and safer than modern fission plants?"
Yes and no. You'll still get a lot of low-level radioactive waste that's not especially dangerous, but you don't get anything that needs to be stored securely for thousands of years. You might still need to store it away for as much as 50-100 years, but on that time-scale it's basically just warehousing, and it'll be mostly harmless long before that.
It'll be safer because you cannot get a meltdown. Unlike fission power plants, you can cut off the fuel supply. If something goes wrong the plasma will dissipate. A fusion reaction is difficult to start and maintain, whereas a fission reaction is difficult to halt. If something goes horribly wrong, at MOST you'll need to replace parts of the tokamak. The fuel is toxic, but that's a negligable hurdle.
A big plus you didnt mention is the fuel. We can't make uranium. We can create tritium/deuterium without too much hassle. It won't run out.
Another big one is that it can't be weaponised. It won't even produce the radioactive waste needed to make a decent dirty bomb.
"There is no perpetual motion energy source."
Perhaps, but when your fuel source is the most abundant substance in the universe, there's "close enough for engineering purposes."
"Where is the balancing "bad" for fusion energy?"
You seem to be confusing thermodynamics with kharma.
Efficient. Reliable. Decentralized. Pick any two.
If you don't know where you are going, you will wind up somewhere else.
I predict that we will have fusion power not before oil reserves are exhausted - too much money/politics/everything involved. Can't be allowed. If we have fusion power production tomorrow - what would all those arabs do? Huh?
It isn't a question of how long. It is more a question of dollars.
It is often said that 20 years ago, the physics community estimated that they could have reactors working in 20 years. People usually ignore that this was only the first half of the estimate -- the other half was the level of funding needed to achieve the result. Needless to say, they received a small (and still shrinking) fraction of the funding they said was necessary, and the result is unsurprising.
Everyone laments the expense of large scale research in creating new basic technology. Bare in mind, however, that the production cost of the movie Spiderman 2 was a bit larger than the budget for the whole US fusion program the year it was released.
In spite of the suggestions and all the tests that I have made, I have not cavato a spider from the hole.
But compared to a fission or coal burning plant? I don't see the radiative waste problem being that onerous.