What is the science behind nuclear power and fission and fusion?

Answer 1

The science behind nuclear power is nuclear physics, and how it describes the loss of binding energy when an atom is split during fission or fused during fusion.

Here is the short explanation... Well, sort of short...

Binding energy (strong atomic force) holds quarks together to form protons and neutrons. There are other energies, such as electromagnetic, weak atomic force, and gravity, but binding energy is the strongest, in the short distance of the atomic nucleus.Binding energy also holds protons and neutrons together to form atomic nuclei. Different amounts of energy are required for different atoms.

When we split an atom into two other lighter atoms, the total energy required to hold the resultant atoms together is less than the original atom. The excess is released as free energy. And other things, but this is the short explanation.

The same thing happens with fusion. When we fuse two light atoms together to form a heavier atom, the energy required to hold the result together is less that the total energy to hold the original two atoms together. Again, the excess is released as free energy.

Now, this may seem contradictory, but it turns out that there is a binding energy curve, starting at hydrogen, peaking quickly at helium, dropping at lithium, starting back up and ascending to a peak at iron, and then gradually descending as we go on up the atomic scale. That is why fusion works for hydrogen, and fission works for uranium.