Final answer:
Nuclear power plants involve nuclear energy, which is converted to heat, then mechanical and electrical energy.
Step-by-step explanation:
In a nuclear power plant, the main energy form involved is nuclear energy. The fuel used in nuclear power plants is typically uranium or plutonium, and this fuel undergoes a process called nuclear fission, where the nucleus of an atom is split into two smaller nuclei. During this process, a large amount of heat is released, which is then used to generate heat energy. This heat energy is then converted into mechanical energy by a steam turbine, and finally into electrical energy by a generator.
Learn more about Energy forms in a nuclear power plant