Here's why:

* Fissionability: Uranium-235 is a fissile isotope, meaning it can sustain a chain reaction when struck by a neutron. This process releases a tremendous amount of energy, which is harnessed to generate electricity.

* Abundance: Uranium is relatively abundant in the Earth's crust, making it a viable fuel source.

* Technological Maturity: Nuclear power plants are designed to efficiently and safely handle uranium fuel.

While uranium is the most widely used metal for nuclear power, other metals play crucial roles in the process:

* Plutonium: This is a byproduct of uranium fission and can also be used as nuclear fuel.

* Thorium: While not directly used for fission, thorium is a fertile material that can be converted into fissile uranium-233 through neutron bombardment. This could potentially become an important source of nuclear fuel in the future.

* Zirconium: This metal is used in cladding fuel rods, preventing the release of radioactive material.

* Steel: Steel is used in various components of nuclear power plants, including reactor vessels, piping, and containment structures.

It's important to note that nuclear power generation does not directly "burn" metals. The energy release comes from the splitting of atoms in a process called nuclear fission, not from a chemical combustion reaction.