They're pretty much opposites.
Take two atoms:
Fission: Break them up, shatter them.
Fusion: Smash the two atoms together, making a larger one.
That's the main difference. And because of...
Fusion would be good if it could be made to work, because it does not produce the active waste that fission does, but it is many years away yet, so not a real choice.
No... Nuclear energy can be produced either by the fusion of 2 lighter nuclei or the fission of a heavier nucleus into 2 aprox equal nuclei by mass. Since Uranium has a very heavy nucleus, it can...