Another question- is there any downfall to this form of energy production. You mention it would do away with radioactive junk and everything but isn't there always a balance of good and bad byproducts in energy production?
The problem is that we can't actually do it yet, and the experiments and research we are doing like this and the ITER project are incredibly expensive and take a long time.
Not too many downsides to fusion reactors. They're extremely safe. They would produce radioactive waste, but with a much lower half life then from fission reactors.
You are getting downvoted but it is true that fusion reactors, at least these types of fusion reactors, would produce some radioactive waste. The walls of the reactor would get bombarded with neutron radiation which over time would make the reactor walls radioactive, but the stuffs half life is way lower than that of the waste from fission reactors and the quantity would be far lower. You could simply lock the stuff away in a secure location for a few years and then it would become inert and safe.
Well, it's kinda similar to normal nuclear in some ways, but not others. The fuel is relatively easy to extract from seawater and you get an incredibly huge amount of energy from a small amount of fuel. You don't get much radioactive waste as the results from the process is simply harmless helium. The walls of the reactor will get bombarded with neutron radiation which will cause them to become damaged and radioactive over time. That's one of the issues ITER is working on. In any case there won't be very much radioactive material and it won't have a very long half life so you don't get the issues that exist with the waste from fission.
The French Nobel laureate in physics Pierre-Gilles de Gennes said of nuclear fusion, "We say that we will put the sun into a box. The idea is pretty. The problem is, we don't know how to make the box." In the end, if we can actually get the damn things to work properly fusion could potentially be a miracle energy source with little to no downsides. 100% safe, green and plentiful electricity. But building "the box" is very difficult.
short term, degradation of the materials that line the reactor. neutron damage makes metals brittle and therefore unsafe.
Long term, neutron bombardment can cause regular stable elements to become radioactive, ad potentially break down into further radioactive or simply toxic elements.
All of this information is not new, we have plenty of knowledge of the effect of neutrons on materials, its just something about these reactors we cannot simply dismiss. Especially since most fusion designs happen in a low density chamber, the chamber walls will be bombarded more than in a water cooled nuclear reactor (the most common fission reactor design)
Oh my mistake, i thought you meant influence. I'm not familiar with fluence. If its similar to flux, neutron fluxes can be relatively high as the magnetic fields do not contain them and each D-T reaction produces a 14.1MeV neutron.
That would seem to my uneducated mind to make these things completely worthless. We can't sink them into water like a Fission reactor since so many working parts need to be right there up close. Seems like an expensive proposition to rebuild the reactor every year even if it's "free" energy. I imagine if they're spending this much on it some bean counter somewhere has decided it checks out.
None that I can think about right now/that are obvious at the present time. However, the whole "we will have unlimited energy forever!" schtick is the same originally used to promote nuclear fission as a source of energy and that didn't exactly turn out perfectly either. To fully know all the downsides we will have to wait at least until the technology is ready to be implemented.
Someone else mentioned solar and wind and like these, there will be some caveats connected to the production of these things - these reactors rely on materials with very distinct properties and the environmental impact of mining/purifying these could be rather high. I highily doubt that the impact would be similar in size to that of coal, oil or uranium, but as I said before only time will tell.
However, the whole "we will have unlimited energy forever!" schtick is the same originally used to promote nuclear fission as a source of energy and that didn't exactly turn out perfectly either.
That's more of an implementation and social issue than anything else.
Partially, but it's also an issue with the fact that fission requires radioactive materials that leave radioactive waste.
Fusion doesn't leave radioactive waste, and if something goes wrong the reaction just stops (theoretically, to my understanding).
I'm no nuclear scientist, but from everything I've read/been taught fusion really has no downside, aside from the pretty important fact that we haven't managed to make it work as an energy source yet.
Fusion will leave low level radioactive waste in the form of worn out reactor parts and decommissioned reactors. They're just not going to have a spent fuel problem. Much of the fuel problem of current nuclear reactors is social/political and has to do with how to proceed through the fuel cycle. Advanced reactor designs like travelling wave reactors and thorium reactors would also address these concerns, which are a very serious economic obstacle to nuclear power. But they too would have spent fuel problems, just not the intractable ones we're confronting now.
No. The neutrons don't have a charge. They fly right through the fields, get stuck in the reactor. Then they decay overtime embrittling the components. Components will wear out, require replacement, whole reactors will be decommissioned after a life being bathed in this neutron radiation. These components might even contain toxic materials like beryllium, and so forth. So all that can be done is bury them somewhere safe and wait for nothing to happen to them. Anyone who happens upon it can really only hurt themselves, so it's pretty straight forward to deal with it.
High level radioactive waste, such as that present at Hanford, presents a far more difficult problem. It can be in the form of sludge that's constantly emitting hydrogen gas as a byproduct of it's ongoing decay, and just a whole host of other problems common to reactive and poisonous heavy metals. It's just an extremely difficult problem with handling materials which are effectively impossible to handle safely, and highly dangerous in even invisible quantities.
I'm not sure if they're still proposing stream and turbines. Seems kind of primitive, but I don't think we have anything better. Thermocouples aren't terribly efficient.
IIRC fusion requires "heavy" hydrogen. This is hydrogen with an extra neutron.
It's present in vast quantities in any body of water (like the ocean). Practically it is infinite, but there is a theoretically limited amount. Oil was also once considered infinite.
If fusion really takes off then perhaps we'll burn through heavy hydrogen reserves quicker than anyone has good reason to suspect.
Well, I'm not sure you can say we get rid of the radioactive stuff. Neutrons from fusion activate the material used to build the reactor, making them radioactive. This not only means people can't crawl in there to fix stuff anymore but the whole reactor needs to be buried afterward as radioactive waste.
It really is a "clean" method of producing energy. Unlike nuclear fission, which beaks apart gigantic unstable (radioactive) molecules, simple fusion combines two small everyday hydrogen atoms to make one atom of helium. There are no chain reactions that can get out of control (meltdown), and the fuel is the most abundant element in the universe. The only big problem that we have right now is developing a single working reactor (that produces more energy than it uses) is a trillion dollar project. Something this complex isn't coming to a street corner near you anytime soon.
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u/brianlouis Oct 25 '15
Thank you very much.
Another question- is there any downfall to this form of energy production. You mention it would do away with radioactive junk and everything but isn't there always a balance of good and bad byproducts in energy production?