Amongst the following, the fissionable materials are
Fissionable materials are materials that can only be made to fission with high-energy (fast) neutrons.
Although formerly used as a synonym for fissile material, fissionable materials also include those (such as uranium-238 & Plutonium 239 ) that can be fissioned only with high-energy neutrons.
Uranium-238 is the only fissionable material occurring in nature. It is useful in explosive devices and in the generation of power.
Plutonium 239 - a highly fissionable isotope of plutonium that is used in atomic weapons and as a reactor fuel