In this process, the fuel used in light water reactors for nuclear power generation is reprocessed, and plutonium is extracted and mixed with uranium to make MOX fuel, which is again used in light water reactors. Even today, a third of the power generated by light water reactors is from the burning of plutonium produced by the reactor, and so there is no considerable difference with natural uranium fuel. Until fast-breeder reactors can be operated at full capacity, recycling of nuclear power fuel is thought to be an effective method.