Hi there!
Nuclear power plants typically use nuclear fuel as their fuel sources, and nuclear fuel is sometimes made up of uranium oxide.
Uranium oxide creates heat, and the heat makes steam, and the steam is pushed throughout an entire process to produce the electricity that powers the nuclear power plants.
Sorry if my answer seemed a bit rusty, but I was trying my best to remember what I learned while I was in school to help answer this question.
I hope this helped you though! :)
