Oct 17 2009, 07:33 PM
QUOTE(bgeh @ Oct 15 2009, 06:05 AM)
For nuclear fusion, the joke is that it's always 50 years away from reality, so in the context of this discussion (~30 years), fusion isn't even a possibility (Note: Unfortunately the joke's moving to becoming 100 years from reality instead)
~lynn~ : Nuclear fusion has been achieved, and not only uncontrolled nuclear fusion, which is often the example used (hydrogen bombs), but controlled nuclear fusion in many purpose built laboratories worldwide (e.g. JET - a tokamak design, there exist other designs too, one of which was featured in spiderman the movie with the lasers, except that it was quite fake
). The problem is that current fusion experiments use up more energy than they ever release out (well actually no, but they only manage to sustain themselves for only a few seconds, which is so short that it doesn't pay back the energy in heating up the plasma in the first place), and thus the reaction isn't self-sustaining, it quenches itself out once you stop supplying energy into it. The next step is to design a reactor that will produce more energy than is input, giving a sustained reaction, and the extra energy being used to generate power for our use. There is a massive problem with this though:
There is an immense neutron flux bombarding the walls of the tokamak, and no one is really sure how long the reactor's walls can withstand this bombardment. This is mainly a material science problem, finding a way to create a material that will be able to withstand this neutron flux without collapsing in some short timeframe.
ITER is supposed to be the first test fusion reactor that will demonstrate a self sustaining reaction (well a plasma really) for about 10-15 mins iirc, which is much more than what current experiments can do. Unfortunately it's hit into funding snags from the participating governments, and the thing seems to have been delayed to 2026 - that's when the real D-T (deuterium-tritium) plasma fusion will occur, while the earlier opening in 2018 will run experiments, and testing the components of the reactor with hydrogen.
So no, fusion is still very far away from being reality. Perhaps our grandkids, but I'd personally be happy to see fusion plants operating on a large commercial scale globally if it happens within our lifetime.
Thats interesting.Still,i thought material problem is also caused by the material couldnt sustain the heat of the fusion reaction.~lynn~ : Nuclear fusion has been achieved, and not only uncontrolled nuclear fusion, which is often the example used (hydrogen bombs), but controlled nuclear fusion in many purpose built laboratories worldwide (e.g. JET - a tokamak design, there exist other designs too, one of which was featured in spiderman the movie with the lasers, except that it was quite fake
). The problem is that current fusion experiments use up more energy than they ever release out (well actually no, but they only manage to sustain themselves for only a few seconds, which is so short that it doesn't pay back the energy in heating up the plasma in the first place), and thus the reaction isn't self-sustaining, it quenches itself out once you stop supplying energy into it. The next step is to design a reactor that will produce more energy than is input, giving a sustained reaction, and the extra energy being used to generate power for our use. There is a massive problem with this though:There is an immense neutron flux bombarding the walls of the tokamak, and no one is really sure how long the reactor's walls can withstand this bombardment. This is mainly a material science problem, finding a way to create a material that will be able to withstand this neutron flux without collapsing in some short timeframe.
ITER is supposed to be the first test fusion reactor that will demonstrate a self sustaining reaction (well a plasma really) for about 10-15 mins iirc, which is much more than what current experiments can do. Unfortunately it's hit into funding snags from the participating governments, and the thing seems to have been delayed to 2026 - that's when the real D-T (deuterium-tritium) plasma fusion will occur, while the earlier opening in 2018 will run experiments, and testing the components of the reactor with hydrogen.
So no, fusion is still very far away from being reality. Perhaps our grandkids, but I'd personally be happy to see fusion plants operating on a large commercial scale globally if it happens within our lifetime.
Damn,ITER is delayed to 2026.Thats bloody long.
I'll personally be very happy to see a fusion reactor too.
QUOTE(joe_star @ Oct 15 2009, 11:51 PM)
http://news.bbc.co.uk/2/hi/technology/8297934.stm
I remembered this article when someone mentioned nuclear energy on a small scale.
Even the current lithium ion batteries is causing environmental issue,i really doubt that a nuclear battery will be ever used in the consumer market. I remembered this article when someone mentioned nuclear energy on a small scale.
QUOTE(DeniseLau @ Oct 16 2009, 06:25 AM)
Yeah, the issue with solar is space, but the best thing about wind is that you can put it offshore where it doesn't ruin the landscape and where you get better winds. I was thinking about South China Sea, but I haven't come across any study/report on yearlong wind strengths.
As for nuclear, it's not a long term solution so I personally don't think it's worth the investments and risk.
How you gonna to build the foundation to support the wind/solar farm in the middle of the ocean with low cost? The cost alone will kill you,as you arent building just an oil rig,you are building a huge farm of wind power generators.As for nuclear, it's not a long term solution so I personally don't think it's worth the investments and risk.
I dont see why nuclear is not a long term solution.Nuclear is a much more sustainable solution to coal,gas or hydro,as it has no carbon emission.France have more than half of it's electricity generated from nuclear.I have yet heard of any large scale reactor failure like Chernobyl happening to France.
The nuclear waste will not be a problem if it's well treated,like burying it underground,rather than dumping them everywhere.Regarding on the risk,i think proper care like having well trained technicians running the plant will eliminate it.Chernobyl's accident happened partly due to untrained technicians running the reactor.
Besides that,i have heard of new designs of nuclear power generators,called very-high-temperature reactor(VHTR) that have a negative temperature coefficient which automatically shuts down the plant when something goes wrong.Chernobyl's reactor has positive temperature coefficient that cause it to go boom.
IMHO,nuclear energy is just getting better with time,until fusion is ready to be used.
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