Three is a good idea but difficult, and five is a good one also. But contrary to popular belief the plutonium created by nuclear reactors cannot be used to make bombs, can't remember why, i learned it in chemistry though, if some chemist wants to chime in. And also the fuel to run the reactor is very small and must only be changed once every 6 months ish. I watched this all in chemistry class but it might be outdated. Also the amount of power a nuclear reactor can generate is enormous compared to pretty much anything else except (fusion, or is it fission i can't remember which is the bigger). So pretty much we would also need MUCH less plants compared to the current energy systems.