One step closer to fusion power - still 30 years away though

[speed3]

École Polytechnique Fédérale de Lausanne

(EPFL) physicists have succeeded for the first time in

preventing the development of instabilities in a nuclear fusion reactor

. It’s an important step forward in the effort to build the ITER fusion reactor, currently in development in Southern France.

Controlling nuclear fusion instabilities | KurzweilAI

Found while looking at a few articles on bigthink.

So are we actually 30 years away now? Given we were 30 years away 30 years ago.

Thoughts and opinions please. Sceptic?Believer?

[Daleski]

Interesting.

I wouldn't be suprised if there was some prevention there considering we haven't heard anything about the Honda Clarity in quite a few years.

An interesting article on the developement of a star chamber
Short Sharp Science: Inside the fusion furnace of California's star chamber

[Thoth]

30 years away from technology making it possible, 100 years before oil companies and others invested in fossil fuels allow it to be implemented

[g0zer]

30 years seems reasonable.

iter follows jet. i guess jet was their prototype they could test their magnetic confinement chambers and iter is building on what they learnt with jet.

sounds like they are moving quite quickly, jet results are dated 2010 and they are building iter now where they can learn about actually trying to make more power than they put in.

then once that is mastered they have to build another pilot plant that actually converts that energy into electricity so thats i guess is 10 years away.

then once its sorted another 20 years to commercial power plants.

[D'Artagnan]

Bring it on. Though like LFTR which is viable now and offers most of the benefits of Fusion, the real battle is political and that hasn't even started.

[speed3]

Yes i think there will some very strong opposition to near limitless and near free power. No one gets to make billions of dollars from it.

[g0zer]

there is a ted talk from the director of JET talking about ITER and funding and he gets a bit hacked off when he starts talking about their funding difficulties.

iirc these pilot plants are not cheap, which is part of the reason why its so difficult to get funding. its a huge capital investment with high risk and long paybacks. i get the impression the R+D is being driven by europeans. im not so sure about limitless and free, maybe in the future we will be paying european power companies for our power and they will be wanting a return for their investment in the tech.

http://en.wikipedia.org/wiki/Tokamak

A tokamak is a device using a magnetic field to confine a plasma in the shape of a torus (doughnut). Achieving a stable plasma equilibrium requires magnetic field lines that move around the torus in a helical shape.

During a full D-T experimental campaign in 1997 JET achieved a world record peak fusion power of 16 MW which equates to a measured gain Q, of approximately 0.7. Q is the ratio of fusion power produced to input heating power. In order to achieve break-even, a Q value greater than 1 is required. A self-sustaining burning plasma requires at least Q=5 (since the alpha particles carry one fifth the fusion energy) and a power plant requires at least Q=10 [5]. As of 1998, a higher Q of 1.25 is claimed for the JT-60 tokamak; however, this was not achieved under real D-T conditions but extrapolated from experiments performed with a pure deuterium (D-D) plasma. Similar extrapolations have not been made for JET, but it is likely that increases in Q over the 1997 measurements could now be achieved if permission to run another full D-T campaign was granted.

high Q means big tokamak

[Virt]

Oooh, an arc-reactor! *starts building Iron man suit*
Very interesting stuff, but as many have already said, dont think we will see it become commonplace in our lifetimes.

[g0zer]

it occurs to me that something ive not heard them talk about is the size of the nuclear reaction you need to sit on top of to get a useful amount of power out.

i dont think there is any question they can sort their confinement tech and build a fusion reactor that outputs plenty of energy. but if you want to bleed out TW of energy then the size of the steady state fusion reaction you have to sit on and confine with your monster tokamak has to be orders of magnitude larger than that.

its all very well to talk about no nuclear waste but if something goes wrong how big is the resulting explosion? thinking about it some more i think 30 years is pie in the sky.

[D'Artagnan]

wrong how big is the resulting explosion?

One reason for promoting LFTR. No water = no pressure = no explosion. Any design that requires keeping the reaction under control is inferior to a design where you have to keep it going. Another reason LFTR is a superior to Uranium based reactors. Not too sure about the Fusion side of things though.

[Falcore]

Once this technology gains momentum it will take off in a massive way.

[filbert]

thinking about it some more i think 30 years is pie in the sky.

or a giant mushroom cloud.

[g0zer]

Not too sure about the Fusion side of things though.

im completely guessing here, but say you need a certain pressure to generate the heat required for their fusion reaction. once you have achieved the pressure requirement energy required to increase the size of the containment field is proportional to the surface area of the containment field.. distance to the 2nd power.

at the same time the volume inside the containment field is going up by a power of 3. the volume is the amount of plasma and is the size of your reaction and energy output.

so i guess the bigger the tokamak the better and more efficient it becomes, it just becomes a question of how much power do you need? if the tech is 100 years away then a fusion power plant needs to power a 22nd century city so they need to be fucking massive.

if the steady state contained energy is 100x the magnitude of the energy you want to bleed out continuously to power your city then its starting to sound like a seriously massive amount of energy to park on earth. like lets install a yellowstone scale supervolcano for every major city on earth. that sounds like a good idea.

[speed3]

One reason for promoting LFTR. No water = no pressure = no explosion. Any design that requires keeping the reaction under control is inferior to a design where you have to keep it going. Another reason LFTR is a superior to Uranium based reactors. Not too sure about the Fusion side of things though.

This.

Cut power to a fission reactor and the reaction continues (minus water to cool it) so it gets hotter and hotter till it melts the fuel rods (meltdown) and everything around it and radiation escapes. Note a fission reactor can NEVER blow up like a nuclear bomb, the uranium isn't enriched enough. Explosions can occur as steam contacts various elements but not nuclear explosions.

Cut power to a fusion reactor and the reaction stops. People winge about not having any power while it's being restored.

As far as my reading has taken me fusion bombs require an initial fission explosion to trigger them to get the required amount of pressure. Unless you blew up a fusion reactor with a fission/fusion bomb I can't see how it would fuck up.

[g0zer]

Cut power to a fusion reactor and the reaction stops.

not so sure that makes it safe, the reaction chamber temperature is 150,000,000C. you know they recreate the conditions of the sun and bottle it inside a EM field. if you turn off the EM field and expose that 150,000,000C environment to earth ambient there will be an explosion commensurate with the amount of energy inside the containment field.




http://www.iter.org/sci/plasmaheating

[speed3]

not so sure that makes it safe, the reaction chamber temperature is 150,000,000C. you know they recreate the conditions of the sun and bottle it inside a EM field. if you turn off the EM field and expose that 150,000,000C environment to earth ambient there will be an explosion commensurate with the amount of energy inside the containment field.




Reaching 150,000,000 °C

I liked that video. I already knew about how a tokamak works in relation to sustaining a reaction at the temp of the sun.

Wouldn't it make sense that if the reaction stopped there wouldn't be anything to be exposed to earth atmosphere? I'm no nuclear physicist and have been trying to find more information relating to it but from what I have seen the plasma would breakdown as it does in current reaction

closest i could find http://www.iter.org/safety
How safe is fusion? In a tokamak fusion device, the quantity of fuel present in the vessel at any one time is sufficient for a few-seconds burn only. It is difficult to reach and maintain the precise conditions necessary for fusion; any disruption in these conditions and the plasma cools within seconds and the reaction stops, much in the same way that a gas burner is extinguished when the fuel tap is turned off. The fusion process is inherently safe; there is no danger of run-away reaction or explosion


Cool shit either way, oh and 3:30 in "here comes the nuclear physics and sorry about that but this is what turns me on"

[g0zer]

How safe is fusion? In a tokamak fusion device, the quantity of fuel present in the vessel at any one time is sufficient for a few-seconds burn only. It is difficult to reach and maintain the precise conditions necessary for fusion; any disruption in these conditions and the plasma cools within seconds and the reaction stops, much in the same way that a gas burner is extinguished when the fuel tap is turned off. The fusion process is inherently safe; there is no danger of run-away reaction or explosion

maybe it is relatively safe. for some reason i had the idea they needed a big steady state reaction but if its only the instantaneous reaction then its not such a big explosion if it was to suffer a containment failure.

500MW is about a 0.1kt TNT explosion enough to wreck their device but not much more than that, given 100% efficiency that power output will burn 0.02g of Lithium per second.