ICF - Internal Confinement Fusion

[Leader Bee]

I was browsing wikipidia today on the subject of Magnetic and Internal confinement reaction in nuclear plants because I feel nuclear energy is the way forward when it comes to alternative energy sources and it interests me.

 

However I came accross the following:

 

http://en.wikipedia.org/wiki/File:Inertial_confinement_fusion.svg

 

"Schematic of the stages of inertial confinement fusion using lasers. The blue arrows represent radiation; orange is blowoff; purple is inwardly transported thermal energy.

2. Fuel is compressed by the rocket-like blowoff of the hot surface material.

3. During the final part of the capsule implosion, the fuel core reaches 20 times the density of lead and ignites at 100,000,000 ˚C.

4. Thermonuclear burn spreads rapidly through the compressed fuel, yielding many times the input energy"

 

Points 1 - 3 make sense but point 4 kinda threw me a bit.

 

Is it just poorly worded or are they suggesting that internal confinement fusion defies the laws of the conservation of energy?

[ajb]

Don't forget there is energy stored in the nuclear binding.

[Leader Bee]

So in reality, as the nuclear fuel was physically placed within the system by somone or something and the fuel has energy within its binding it is not creation of energy but a way of converting one form of energy into another?

[ajb]

Just as in any fuel.

 

Think about burning coal or wood. You get more out than you put in, but this is not in violation of any laws as the fuel is really just an energy store.

[swansont]

Don't forget there is energy stored in the nuclear binding.

 

Arg. Sorry, pet peeve: Energy is released in forming bonds, or in forming stronger bonds. The bond represents an energy deficit with respect to an unbound system. That's why it's a bound system — you have to add energy to break the bond. So I object to the commonly-used wording that energy is stored in bonds; I think it conveys a misconception.

 

The final product has stronger bonds than the reactants. That's why energy is released.

[ajb]

Arg. Sorry, pet peeve: Energy is released in forming bonds, or in forming stronger bonds. The bond represents an energy deficit with respect to an unbound system. That's why it's a bound system — you have to add energy to break the bond. So I object to the commonly-used wording that energy is stored in bonds; I think it conveys a misconception.

 

The final product has stronger bonds than the reactants. That's why energy is released.

 

Yes, ok. Poor wording.

[Mr Skeptic]

Right, "burning" in the nuclear sense. All it says is that you get more energy out of it than you put in, because you are forming stronger nuclear bonds. The trick is that this energy then needs to be converted to electricity, and the energy you put in also has inefficiencies. So far, I'm pretty sure we get less useable energy out.