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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."
In the same sense, my logging on to slashdot today is akin to designing TCP/IP.
Reality has a conservative bias: it conserves mass, energy, momentum...
Step away from the car... This is a fusion research reactor, not a reactor to be used as a power source...
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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Slashdot has a strange fascination with potential energy solutions. Ah...so much energy wasted thinking about potential energy.
...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).
50-100 years is way better than tens of thousands of years, as with fission waste. That won't outlast the containers it's in.
I'm in the hole of the broadband donut.
If anyone is interested there is a wealth of information on JETs website
Including some pretty cool pictures of their kit.
50-100 years is nothing, and it's not the fuel or exhaust that you need to worry about, only the parts of the reactor itself that become radioactive from neutron bombardment. So, we only need to store retired reactor parts for 50-100 years, which is much less mass and much less duration than what we currently produce from nuclear plants, and massivly less environmental impact when compared to the equivilent fossil fuel usage.
Goodness -- I was surprised by the number of wildly incorrect postings about nuclear fusion. Some I could have tried to clear up myself, but a better recommendation would just be to read up for five minutes before posting some misinformed comment.
Wikipedia has a good article on Fusion Power. Read it, then post.
Only on slashdot can you be called an idiot if you don't know anything about nuclear fusion.
I think perhaps you don't grasp the fundamentals of what a magnetically confided burning plasma reactor really means. While a reactor of this sort aims at providing net power production via nuclear fusion, you have to be aware that a significant amount of energy is used to create the magnetic fields, and other auxillory control mechanisms like nuetral particle beams and radio/microwave power used in controlling the plasma to get the very precise conditions under which net power can be achieved. You turn off any of these control systems..the plasma start under performing. Unlike fission, you aren't trying to control a run-away process by slowing it down. In terresterial magnetic confinement fusion reactors..you are doing everything you can think of to produce the very specific conditions that maximize the amount of nuclear reactions. And if the plasma conditions change or your control system fails, plasma performance quickly degrades on its own because of naturally occuring instabilities in the magnetohydrodynamics that govern bulk plasma behavior.
Nothing like a world ending 'meltdown' can happen, a magnetically confided plasma has so many different ways to dissipate energy. The trick has always been and always will be to get enough nuclear reactions out of this plasmas to make it worth while to build them as an energy source, becuase running them invovles using lots of energy just to create the plasmas conditions at all.
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)
I think you are way off base. Fusion power would not end energy companies. I doubt it would even end fossile fuel exploitation. Oil gives more bang for the buck then any other fuel source which is why we are so addicted to the damned stuff. Bonus points for the fact that it is cheap and easy to make an engine that will run on it.
Now, fusion offers a great deal of possibilities, but there are two very large problems with it even when it is 'worked out'. First, it will be expensive. It is a major task to build such a plants. Building enough to power the world would take many decades and cost far more then I imagine most nations would be willing to spend. I am not saying that it couldn't eventually be done, but don't expect it to happen over night. Further, even if the world was covered in fusion plants, that energy would not be free. You still need to pay for all the parts and labor it takes to keep such a plant going. Sure, you might cut costs on material expenses, but they would rise everywhere else. Electricty wouldn't suddenly become cheap, just abundent. Second, fusion is large. You can't throw a fusion engine in your car and electric motors just don't have the capacity of a gas engine. If electricity was free tomorrow we still wouldn't hav electric cars.
I doubt energy companies are cowering at the prospects of fusion. Even if fusion was to completely upset the need for oil and coal, there is still the fact that people need energy and in a nation like the US that energy is going to be brought by a corportation. An energy company is in a perfect position to fill that need. At worst it means they have to shift their bussiness to focus less on oil and coal and move to fussion. The world won't end for them.
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.
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Exactly. Let me spew some physics for a moment.
The temperature of a gas is related to how fast the particles of the gas are moving. The hotter the gas, the faster the average kinetic energy. However, not all the particles move at the same speed. There is a distribution of speeds, with most of the particles at or below the average speed. However, a very thin "tail" of particles travels at speeds much, much higher than the average. In the Sun, it is these very high-speed nuclei, way above the average kinetic energy of the plasma, which collide and fuse.
So, why can't we get fusion with temperatures equivalent to the center of the Sun? Pressure. We can't hope to achieve pressures anywhere near that in the Sun. In the sun, the pressure is so immense that the particles are squeezed extremely close together. Imagine these particles moving at insane velocities, in such close quarters. They will collide with each other extremely often. This extremely high collision rate allows fusion to occur, because it brings the super-high-energy nuclei together more often.
On Earth, at very low pressures (at least relative to the core of the Sun), the particles are moving fast enough to fuse, but they just don't collide often enough. They aren't close enough together. Thus, to make up for this, we must increase the temperature so that a larger fraction of the particles are in the kinetic energy realm where fusion can occur. In other words, we make up for the lack of pressure by increasing the temperature.