Question about fusion reactors

[bdewoody]

OK, I know how a fission reactor transmits it's energy to electricity, the rods sit in a water bath which heats up and transfers this heat to a non radioactive water loop which then becomes steam to drive turbines which generate the electrical current.

How will a fusion reactor transfer it's energy to become electricity? It seems you can't run water thru the fusion chamber so I'm a little fuzzy on how the energy transfer takes place.

 

[neuvik]

The hope is for fusion to heat water in to steam for use in a steam turbine. The National Ignition Facility is not going to be doing that immediately but that is what the research is hopefully going to produce. You could also run the byproduct of Helium (from the Deuterium - Tritium fusion) through a turbine as well.

Here Lawrence Livermore’s write up on IFE for the NIF:
https://lasers.llnl.gov/programs/ife/how_ife_works.php

 

[theridane]

There are also designs that exploit the strong magnetic field of the plasma body and use it to generate electricity directly. Heat transfer is used in highly efficient reactors (e.g. tokamaks, where the magnetic field is used for confinement and therefore cannot be used to generate power), direct conversion (with induction coils) is used in fusion engines with coils around the exhaust. I think.

Or should I say will be used :mrgreen:

 

[nimbus]

http://www.askmar.com/Direct_Energy.html
Don't have time to put it in a nutshell, but there it is if you're curious.

 

[RWJ]

The positively charged byproducts of an aneutronic reaction could be converted directly into electricity by an association of electric fields and neutralization/recombination using electrons: http://www.youtube.com/watch?v=YXLshYYsK8I

 

[MeteorWayne]

YoiTube is such a great source for physics that is nutty

 

[RWJ]

YoiTube is such a great source for physics that is nutty

This process uses only basic physics concepts.
What is the problem?

Sometimes I think, today in physics, if someone says "two plus two makes four" then he is a nutty.
Else, if someone says "two plus two makes five squared" then he is a genius.

 

[bdewoody]

Looks to me like after 35 years of being only 20 years from a working fusion power plant that they are still not sure of the best way to turn the energy from the reaction into electricity in the power grid.

 

[kelvinzero]

Looks to me like after 35 years of being only 20 years from a working fusion power plant that they are still not sure of the best way to turn the energy from the reaction into electricity in the power grid.

That is mainly because none of them work yet, and the answer depends on which version we are talking about.

 

[MeteorWayne]

And as he said, it's been 20 years away for 35 years....

 

[nimbus]

Not quite 20 years away (if the milestone is net power somewhere between post-prototype and pre-production) for a number of schemes right now. Polywell, Focus Fusion, NIF, General Fusion's piston scheme, and others.

 

[MeteorWayne]

Talk to me in 20 years...

 

[nimbus]

It'd definitely be damning for all of them to fail.

 

[bdewoody]

I think the failure to develope a working power producing fusion system is the biggest scientific failure of my lifetime. I most likely won't be around in 20 years, and yet when I was in college it seemed so promising.

 

[darkmatter4brains]

I watched a show on Fusion Power not too long ago. Had that young guy, from the UK I think, that you see on hosting lots of physics/science shows anymore. I can't remember exactly what he said, but it was about priorities. It was something like: "We spend more money on ringtones in the UK alone, than the entire world does on fusion research"

I think the heart of the problem lies there. If we really wanted to get fusion going, I think we could.

reminds me a lot of the moon. 40+ years ago we got there in 10 years. Now we cant get there in less than 15. We suck

 

[centsworth_II]

...reminds me a lot of the moon. 40+ years ago we got there in 10 years. Now we cant get there in less than 15. We suck

On the other hand, we can put more computing power in a 16 year old's cell phone than there was on the Apollo spacecraft.

We rule!

 

[Astro_Robert]

I think Fusion Power suffers from 2 things.

#1 we have historically underestimated development activities, and I mean accross the board, not just for big ticket Physics experiments. (Always wanting to add the latest capabilities in the middle of development contributes to this, in this case change in reactor type)

#2 political winds change, and it can be difficult to continue funding such a program for potentially a decade or more. Just like Clinton canned the Super-Collider, I believe he also pulled out of the original ITER agreement. It has now been restructured, but still who is going to champion physics expenditure for the next 20-35 years?

When you are spending ~$6B on a science project, even one that has a potentially huge payoff like fusion power, funding gets enormously complicated. Once you have more than 1 or 2 nations partnering without a clear authority figure then it becomes impossibly complex.

 

[Jacksonjr0458]

A fusion engine would propably be used to simply heat fuel.

 

[Jacksonjr0458]

A fusion engine would propably be used to simply heat fuel.

We are talking about for spacecraft, right?

 

[js117]

OK, I know how a fission reactor transmits it's energy to electricity, the rods sit in a water bath which heats up and transfers this heat to a non radioactive water loop which then becomes steam to drive turbines which generate the electrical current.

How will a fusion reactor transfer it's energy to become electricity? It seems you can't run water thru the fusion chamber so I'm a little fuzzy on how the energy transfer takes place.

A side bar, how would they generate electrical current for space crafts.( fission, Fusion )

 

[docm]

Franklin Chang-Diaz has said that VASIMR could be evolved into a fusion drive.

 

[billslugg]

How will a fusion reactor transfer it's energy to become electricity?

The 'direct to electricity' option is only valid for fusion reactions that emit charged particles. The fusion reaction we are most likely to harness first is between deuterium and tritium and releases mostly neutrons. The volume immediately around the fusion chamber would be comprised of huge chunks of iron inside of which which pipes would carry the feedwater and steam.

 

[fiercekf]

ITER is still going - http://www.iter.org/default.aspx

 

[aaron38]

It's likely that the first true fusion power reactor will be an MHD power take-off on a ship's drive. The MHD efficiency won't be high, so it'll need a high flow rate. That's the thrust propelling the ship. It'll be a D-He3 reactor, which will probably have it's first application on a ship. The technology roadmap will be from ship propulsion to terrestrial power.

 

[Folcrom]

Fusion power generators can easily transfer their heat to energy by using a simple liquid lithium blanket.