A nuclear reactor is not complecated unless you want it to be. Start small. Make sure you know all the elements and walls inside out. It helps you to know special functions.
Think innovatively. A lot of ideas on the server are 'samey'. Make something original and you'll be a hit.

Not possible. The reaction has to be in busrts to allow the dissipitation of pressure and waste. You could have have two chambers, one works as the other prepares itself for the next firinf sequence.