# What isotopes are used in nuclear power?

##### 1 Answer

*Uranium-235*, *Plutonium-239*, *Thorium-232* and *Uranium-233* are used or could be used in nuclear power.

While *uranium-235* is the naturally occurring fissionable isotope, there are other isotopes which can be induced to fission by neutron bombardment.

*Plutonium-239* is also fissionable by bombardment with slow neutrons. *Plutonium-239* can be produced by "breeding" it from uranium-238.

*Uranium-238*, which makes up *U-238* has a small probability for spontaneous fission and also a small probability of fission when bombarded with fast neutrons, but it is not useful as a nuclear fuel source.

*Thorium-232* is fissionable, so could conceivably be used as a nuclear fuel. The only other isotope which is known to undergo fission upon slow-neutron bombardment is *uranium-233*.