[en] Nowadays, worries about energy generation are not restricted only due to economic aspects but also its sustainability. More and more the center of debate involves the minimization of the waste and the better usage of natural resources. Plutonium produced in nuclear plants is usually considered a proliferating waste in need of disposal, but it could also be recycled and used to start other fuel cycles. In literature there are lots of papers about the usage of Th-Pu fuel, a fuel composed of a mix of thorium and recycled plutonium, to eliminate transuranic (TRU) waste in light water reactors (LWR). In addition, "2"3"3U is produced and this fissile material can be reused to feed another reactor. In Brazil such research is justified, once its nuclear matrix is composed by this kind of reactor and also for having one of the largest thorium reserves of the world in its territory, according to the International Atomic Energy Agency (IAEA). In this sense, this paper looks for recent studies about this kind process and try present important characteristics of Th-Pu fuel, including safety aspects and proliferation concerns, such as reactivity and the differences between plutonium used to produce weapons and plutonium used as reactor fuel. (author)