Re: Using Nuclear Energy to charge Plasma?

I think the idea you are proposing is to use the energy released in a nuclear reactor to ionize a gas, creating a plasma. To "ionize" is to strip electrons (the light-weight, negatively-charged particles) from an atom, resulting in a "gas" of positive ions and negative electrons that is called a plasma. Because plasmas are composed of electrically charged particles, they can, in principle, be manipulated by electric and magnetic fields. You are suggesting that the energy now stored in the hot plasma particles can be easily transported and used.

The two challenges to the idea are the initial production of the plasma and then the handling of the plasma after that.

The energy from a fission reaction, such as occurs in a nuclear reactor, is released primarily in neutrons. These are relatively heavy, uncharged particles from the nuclei of atoms that come flying out when the nucleus breaks apart ("fissions"). The fast neutrons that collide with other nuclei in the uranium fuel cause those nuclei to break up, releasing more neutrons and maintaining the reaction. The neutrons which escape the fuel pile are absorbed in neighboring material, causing it to heat up. This heat is used to convert water to steam and drive turbines to make electricity, just like the heat from burning coal or oil is used in non-nuclear power plants.

The challenge in making the plasma as you suggest is in the neutrons. Because the particles are uncharged, they don't interact with atoms in such a way as to ionize them. To do that, you need an electric field, which is created only by charged particles. The neutrons interact only with an atom's nucleus. The only effective way we have of getting the energy from a neutron is to send it into a material where it can collide with all the nuclei, causing those atoms to heat up. Eventually, the neutron slows down enough that it gets captured by a nucleus.

Imagine the cue ball on a billiard table careening around until it has transferred all it's energy to the solids and stripes. Getting electricity from this heat is very inefficient, but it's the only technique we've got right now. Fusion power faces the same challenge, because most of the energy in that case is also released in the neutrons.

In addition, plasmas are not nearly as easy to store and manipulate as you might think. Any time you apply an electric field, the positively-charged ions and the negatively-charged electrons go flying off in opposite directions. In principle, they can be held by magnetic fields, because both particles will "orbit" magnetic field lines, just in opposite directions; however, there are many other effects that conspire to cause the particles to diffuse quickly across the magnetic fields and escape.

As a result, most plasma "storage" takes place on the timescale of milliseconds. Any longer, and the plasma must be constantly fed new particles to replace the lost ones. In your scheme, lost particles mean lost energy.

You are on the right track in that energy conversion would be much more efficient if we could get the nuclear energy into charged particles, because we could convert that directly to electricity by sending the current of particles through a magnetic field, essentially like a big transformer. Going through the intermediate stage of heating water introduces a huge inefficiency, but nature seems intent on making life difficult for us.

There is a type of fusion reaction, I think a carbon-carbon fusion, that releases most of its energy in positively-charged nuclear particles called protons. The problem there is that one must heat the carbon into a plasma hotter than the core of the Sun in order to get it to fuse! Some people hope that the reaction can be "catalyzed" with other particles to cause it to occur at lower temperatures, but it still must be in a plasma state. See the above discussion about the challenges of holding a plasma together to get a taste of what fusion researchers are facing.