text: There are several fuels that can incorporate plutonium in their initial composition at their beginning of cycle and have a smaller amount of this element at the end of cycle. During the cycle, plutonium can be burnt in a power reactor, generating electricity. This process is not only interesting from a power generation standpoint, but also due to its capability of consuming the surplus weapons grade plutonium from the weapons program and plutonium resulting of reprocessing used nuclear fuel.
  Mixed oxide fuel is one of these. Its blend of oxides of plutonium and uranium constitutes an alternative to the low enriched uranium fuel predominantly used in light water reactors. Since uranium is present in mixed oxide, although plutonium will be burnt, second generation plutonium will be produced through the radiative capture of uranium-238 and the two subsequent beta minus decays.
  Fuels with plutonium and thorium are also an option. In these, the neutrons released in the fission of plutonium are captured by thorium-232. After this radiative capture, thorium-232 becomes thorium-233, which undergoes two beta minus decays resulting in the production of the fissile isotope uranium-233. The radiative capture cross section for thorium-232 is more than three times that of uranium-238, yielding a higher conversion to fissile fuel than that from uranium-238. Due to the absence of uranium in the fuel, there is no second generation plutonium produced, and the amount of plutonium burnt will be higher than in mixed oxide fuels. However, uranium-233, which is fissile, will be present in the used nuclear fuel. Weapons-grade and reactor-grade plutonium can be used in plutonium–thorium fuels, with weapons-grade plutonium being the one that shows a bigger reduction in the amount of plutonium-239.