What do nuclear power plants use as a fuel source? Where is this fuel source obtained?

Only 0.7% of natural uranium is 'fissile', or capable of undergoing fission, the process by which energy is produced in a nuclear reactor. The form, or isotope, of uranium which is fissile is the uranium-235 (U-235) isotope ... Most is then converted into uranium hexafluoride, ready for the enrichment plant.

Use of fissionable elements to produce heat and is obtained in underground mines.

Explanation:

Nuclear plants use chemical elements that when subjected to nuclear reactions (fission or fusion) release considerable amounts of energy (heat). This heat is used to produce steam and move turbines that generate electrical energy.

The nuclear compounds are obtained mainly in underground mines, after this the compounds are extracted and subjected to purification processes the purified element is taken to nuclear power plants where they are used to obtain the electrical energy.