[en] In France, according to the law, all nuclear fuel cycle facilities have to undergo a Periodic Safety Review every ten years. Concerning UP2-800, a spent fuel reprocessing facility of La Hague nuclear site, one point specially reviewed is the impact of aging effects on the Nuclear Criticality Safety of this facility. Indeed, dimensions of geometrically safe equipment and chemical compositions of neutron absorbers can be affected by aging effects. This paper presents a methodology used for reviewing these impacts and some results of this review transmitted to the French Nuclear Safety Authority. (authors)