[en] A 'yellow cake', in which the uranium content is about 60%, is obtained from uranium ores by means of chemical refining. Then the yellow cake is converted into UF₆ that is the raw materials of uranium enrichment. The centrifuge is the most popular method for the uranium enrichment in the world. The enriched uranium is used in the LWR plant as UO₂ pellet form. The uranium and plutonium are recovered from the spent fuel in the reprocessing plant and they are going to be used as nuclear fuel again. Currently, in the world, all reprocessing plants under commercial operation adopt the PUREX process using TBP as extractant. The preprocessing process consists of a mechanical head-end process (such as a shearing process), a dissolution process, a clarification process, a solvent extraction process, and so on. The nitric acid and the solvent (mix of TBP and n-dodecane as diluent) are recycled in the plant and high level liquid waste is finally vitrified into glass form. In Japan, through the experience of the Tokai Reprocessing Plant, the first commercial plant, i.e. the Rokkasho Reprocessing Plant, will start its operation soon. The spent fuel from FBR can be reprocessed by the PUREX process taking into account of its characteristics such as high plutonium content rate, high burn-up, and the structure of fuel assembly. Currently, the adoption of an innovative technology is examined aiming for further economy improvement and the reduction of the waste load. The safeguards is the activity to prevent the diversion of nuclear material. (author)