Nuclear Fusion? When do we get the energy of the future?

[BiggyZ321]

So in 2019 or 2020 the ITER (Pronounced "eater") will be finished hopefully. I myself am skeptical as to it being finished by then. I'm 14 so if the plans go as according it'll be great because I'll be able to see the beautiful price of scientific ingenuity and machinery in action. I would kill to work at this thing. But like I said I'm skeptic about it. And not to mention what the scientists working on it are saying. That this beauty will pump out 10 times more energy put into it. That means there's a viable option of pursuing a bunch of reactors if it works as planned. If this happens it'll be the day I cry out of pure beauty. Now my field of interest is nuclear fusion so it it works out right it will be perfectly planned because I'll be able to see it and possibly work there. Anyways my question is does anyone think it'll be done on time and be fulfilling it's promise of energy? And does anyone think I'll be able to work there if it is?

[imatfaal]

If you are 14 and want to work at ITER or similar you have one option - study hard and you will work at ITER one day!

 

Tell us why you are sceptical about it? Scepticism is often phrased as "healthy scepticism" - and this can be as misleading and dangerous a mindset as being naively trusting. Uninformed dismissal of potential progress, of current understanding, and of mankind's ability to innovate is rife in society at present - it is fashionable and easily defended to be dismissive and disdainful of the hopes and work of others. To be clear I am not accusing you of this - quite the opposite as I am sure you have your reasons otherwise you would not have posted on a science site.

[Enthalpy]

ITER, and more fusion reactor attempts, are a huge disappointment to me.

 

They need tritium to work - a tokamak like ITER cannot use anything else, even within the usual next 50 years - but tritium isn't available in significant amounts on Earth. Only deuterium.

 

Presently, tritium is made by uranium reactors, in tiny amounts. Uranium reactors produce 200MeV energy as they make <1 neutron available to make one tritium, and this tritium produces only 20MeV in a fusion reactor. Instead of obtaining 90% electricity from uranium and 10% from fusion, 100% from uranium is better.

 

So the fusion reactor must breed the tritium it uses, but that's difficult. One deuterium-tritium fusion gives one neutron. One neutron makes one tritium from one lithium. Because of the losses, this scheme can't work.

 

The proposed method is a neutron multiplier. The neutron from fusion breaks a lead atom (there is too little beryllium on Earth) to release more neutrons, which react with lithium to make tritium. Such an experiment is planned on ITER: search for tritium breeding blanket

 

But even if regeneration did work (more tritium produced than consumed, which is far from certain now), breaking lead atoms (or any heavy one) produces radioactivity the big way: only a fraction of the neutron and lead reaction make nasty products, but because fusing one tritium makes only 25MeV, eight times more lead atoms must react than uranium atoms are fissioned for the same heat. Quick hand estimates tell that the nasty radioisotopes are as abundent as by uranium fission.

 

I put some hand estimates there:

http://saposjoint.net/Forum/viewtopic.php?f=66&t=2450&start=10#p32310

this should be done by software, which would probably find more undesireable radioisotopes.

Note that many links to data I put there are broken.

 

I understand ITER looks like a nice toy, but from the radioactivity issue, I consider it the wrong direction. Worse: other energy sources are working better and better while fusion isn't ready by far. So working on a tokamak may be fun, but useless. One's time is better invested in finding cheap and efficient ways to store electricity, since wind for instance already produces cheaper energy than uranium.

[Delbert]

Well, according to reports it's been done in a school classroom by a 13 year old:- http://www.bbc.co.uk/news/science-environment-26450494

 

Cold fusion again?

[Greg H.]

Well, according to reports it's been done in a school classroom by a 13 year old:- http://www.bbc.co.uk/news/science-environment-26450494

 

Cold fusion again?

Actually, if you look at the experimental setup he used, it's based on Inertial Electrostatic Confinement, which is most decidedly not cold fusion.

 

See http://www.dailymail.co.uk/sciencetech/article-2573998/I-star-jar-13-year-old-youngest-person-world-build-NUCLEAR-FUSION-REACTOR.html for more detail.

 

And the problem isn't getting atoms to fuse - we've been doing that since the 1950's. It's getting them to fuse in a controlled fashion while producing more energy than the reaction consumes to remain stable that's the trick.

Edited March 6, 2014 by Greg H.