Nuclear fusion, or fission, aren't anything like M/AM. You can have a M/AM with atoms/molecules, and with protons and negatons, and electrons and positrons. But you can't do nuclear fission or fusion with electrons. ;)
Each element has a specific "strength", it's actually a curve. This strength is actually energy holding together the atom, and is in fact responsible why some atoms have a relatively "low" half-life (half-life is the time in which it takes for half of a volume of atoms to "self destruct" on their own, uranium has a relative low half-life, of 704 million years for 235 (an "isotope" of uranium, the word describes it perfectly so I won't go into everything, otherwise I'll be repeating most of my physics and chemistry lessons
). But iron, which has the greatest strength btw, is in 3 of 7 isotopes "stable", meaning it either has no half-life or we haven't been able to measure it yet.
Now, both fission and fusion work on the fact that different elements have different strengths. In case of fission, you break up an atom by sending some other, fast moving, particle at it, say, another piece of uranium proppeled by an explosive (basis for atleast Hiroshima type nuclear bombs). So the atom breaks up, but into what? Two smaller atoms. Now these other atoms will have different strengths. And if you add everything up, you will notice that there is a discrepancy between everything. Where did that energy go? Remember, nothing gets lost, ever, maybe it is just converted into something else. In this case, radiation, either gamma, beta or alpha, mostlikely a mixture of all 3. Gamma is pure energy (in fact a high frequency em wave/particle, an actual form of light), beta radiation are electrons and alpha radiation are helium nuclei (sp). Where am I going? The act of going from an unstable to a more stable element releases energy, since less needs to be used to keep it stable. And that energy can be converted into heat which drives a steam turbine.
Anyway, fission works the same way, except it's going the other way around, we combine atoms into bigger ones, for example, deuterium (yes, they are one and the say) into helium. And again, here, from going from a more unstable to a more stable element releases energy.
You can keep combining atoms all the way up to iron, and then it will take far more energy to combine the cores than you get out of it (in fact, you won't get energy out of it). The same with coming from uranium all the way down to iron, when you get to iron, you will need more energy to break it up than you get out of it.
Now how is this diffrent from M/AM? When Matter and Antimatter collide (just touch is enough), they annihilation eachother producing gamma radiation (any M/AM reaction does this, and maybe "rest" matter or antimatter, if the mix ratio isn't 1:1). And that gamma radiation can be used to heat up water, and the steam driving a turbine.
