Confused over what engineer I want to be, please help me out?

Given your desire to work on waste management for fission or the design of future fusion reactors, I would highly doubt you would end up at a power plant. More likely, you will end up at Idaho National Lab (waste), Livermore (fusion), or Oak Ridge (waste). Try to get an internship at Pacific Northwest National Lab (PNL) during your undergraduate years. You have plenty of options, which make your fears about power plants a moot point.