Final answer:
The power in the use of nuclear fuels comes from the splitting of uranium-235 atoms through a process called nuclear fission.
Step-by-step explanation:
Nuclear power plants use the energy from nuclear fission to produce electricity. The power comes from the splitting of uranium-235 atoms, a process known as nuclear fission. When uranium-235 atoms are split, they release a large amount of energy in the form of heat and high-energy radiation. This energy is then used to generate electricity.