how to restart a fusion reactor in space?

[insane_alien]

So, big fusion reactor + fuelcell capable of running of reactor fuel supply(hydrogen) and either oxygen specifically for the fuel cell or general supply.

once the reactor starts you can recover fuel and oxygen used in the fuel cell and everything is fine.

 

[RisingFury]

And let's not forget that fuel for fission reactors is very limited. That makes it at least in the long term not really an option.

By that time we'll probably have the capability of economically viable mining of other bodies in the solar system. If there's uranium out there, we'll get it.


Although I do believe fusion should power the star ships of the distant future...

 

[insane_alien]

Fission Fuel isn't that limited, we haven't even started consuming thorium for reactor fuels. it's as common as tin. but still, fission is messy.

 

[the.punk]

So, big fusion reactor + fuelcell capable of running of reactor fuel supply(hydrogen) and either oxygen specifically for the fuel cell or general supply.

once the reactor starts you can recover fuel and oxygen used in the fuel cell and everything is fine.

I agree with this. Should be an option. And no use of a fission reactor.
I know how an fuel cell works. It needs hydrogen and oxygen and creats water + electricity.
But what do you mean with the recovery when the reactor starts?

 

[insane_alien]

well, fuelcells can be run in reverse by putting power and water in and getting hydrogen an oxygen out. as the electricity is coming from fusion which produces much much more energy than it takes to break appart water, it becomes perfectly feasible to do this.

 

[the.punk]

Oh..yes. I forgot that they can do it in reverse.

 

[tgep]

I would use a cold fusion reactor to jumpstart the process. You could also use the cold fusion reactor as an emergency power source.

 

[insane_alien]

except cold fusion doesn't really exist.

 

[the.punk]

There was something like that, but I think it isn't realizable.
There are two types like that:
http://en.wikipedia.org/wiki/Cold_fusion

http://en.wikipedia.org/wiki/Muon-catalyzed_fusion this is a second type of cold fusion, but is a physical it is different.

 

[RisingFury]

Yes, there was also the hope that sonoluminescence would produce fusion... no joy on that one either.

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

 

[Brycesv1]

as far as nuclear waste storage and disposal goes...

i think if you were in space you wouldnt have to store or transfer it anywhere because... ur in space. just jettison the waste directly from the reactor.

plz correct me if im wrong, but i think that would work

 

[the.punk]

as far as nuclear waste storage and disposal goes...

i think if you were in space you wouldnt have to store or transfer it anywhere because... ur in space. just jettison the waste directly from the reactor.

plz correct me if im wrong, but i think that would work

You cannot just stop the reaction. And this waste has still energie and is "glowing" . Throwing out would also not be good because then you throw out your fuel.
We don't need fission reactors when we have fusion reactors because they can be shut down and don't produce.

 

[RisingFury]

as far as nuclear waste storage and disposal goes...

i think if you were in space you wouldnt have to store or transfer it anywhere because... ur in space. just jettison the waste directly from the reactor.

plz correct me if im wrong, but i think that would work

Ideally, yes... for all nuclear reactors that have been sent in space so far, the thinking was to ejected them into high orbits that won't decay for 1000's of years... but this still leaves them floating around as space junk.

I think finding an asteroid, drilling a hole in it and then shoving all our nuclear space-fuel would be a better way of disposing of high profile nuclear waste.
This way you have them concentrated in one place that you can continuously survey and make sure nobody with bad intentions gets it.

 

[the.punk]

Sure. You can just throw them out. The problem is also that in this waste is still energie we can't use so good. They are radioactive and still "glowing".

 

[Brycesv1]

but like if you were to go to the outer planets and you jettison your depleted fuel. that would keep going until it gets caught in a planets gravity and crashes. the chances of someone finding and having bad intentions with it is pretty much nil

on a side note that made me LOL. my mother thinks that satalites sit in orbit for a while, then they get caught by gravity after a long time so the fall back down. i couldnt for the life of me explain to her that satalites fall down because they are still in the atmosphere and so over time they slow down to the point where their velocity cant hold them in orbit anymore.

 

[Ghostrider]

but like if you were to go to the outer planets and you jettison your depleted fuel. that would keep going until it gets caught in a planets gravity and crashes. the chances of someone finding and having bad intentions with it is pretty much nil.

Do not underestimate this guy:

Opinable fashion choices apart, he's not someone you would want to mess with.

 

[Urwumpe]

If you're going to use a Tokamak design you will definitely need some kind of capacitor array as Tokamaks can only be operated in a pulsed way (5 - 10 Minutes iirc). So you need to restart the thing constantly. There is also research being done on Stellarators that can run continuously but they are a more complicated design compared to Tokamaks.
And then there is the Polywell design conceived by Robert W. Bussard and his team that if it works (which is not at all sure yet) could get us fusion reactors much more compact than Tokamaks could ever be and might even open up possibilities for using reactions with very low neutron generation (i.e. H-Boron).

Actually, it is completely opposite. Tokamaks are closer to continuous operation, but have the problem that they can currently only reach got plasma parameters at large dimensions.

The Polywell design on the other hand is only able to reach it's reported great power output during short pulses. And between pulses, it uses even more power than it produces during the pulses, though the Polywell design seems to be better in effectivity as earlier inertial containment reactors.

The problem for both is reactor designs is Bremsstrahlung, a kind of radiation you get, when you accelerate charged particles. Tokamaks produce a constant energy loss that way, Polywell and other fusor designs currently produce extremely strong radiation bursts between the pulses, when the ions have to change their direction of travel and get pushed into the core again.

But well, Bussard said his own invention is better in a Internet Video, so it must be the truth right?

 

[jedidia]

but like if you were to go to the outer planets and you jettison your depleted fuel. that would keep going until it gets caught in a planets gravity and crashes. the chances of someone finding and having bad intentions with it is pretty much nil

Yeah, I remember getting fined in first encounters for throwing my nuclear waste out of the airlock in the SOL system...:lol:

 

[ijuin]

But well, Bussard said his own invention is better in a Internet Video, so it must be the truth right?

LOL! But seriously, we should at least look at it close enough to feel certain of whether it can be made to work or not instead of just going with a gut reaction.

 

[Urwumpe]

LOL! But seriously, we should at least look at it close enough to feel certain of whether it can be made to work or not instead of just going with a gut reaction.

True, but for that, you would also need to get more out of Polywell than just the rough config and the improvements over other fusor designs. Bussard didn't even publish the experiment setup well enough to explain which quantity he measured when.

---------- Post added at 10:11 AM ---------- Previous post was at 10:01 AM ----------

BTW... another fusion hype around... mechanical fusion xD

http://generalfusion.com/