[en] The need for reducing the intrinsic conservatism in the criticality safety assessment has led to the development of validated methods for assessing the reactivity effects associated with fuel burnup. This paper gives an overview of the work being performed to investigate the spent fuel characteristics and nuclear criticality safety of the reactor RA spent fuel storage. An analysis methodology is presented along with information representing the validation of the methods and geometrical models. Finally, the criticality safety analysis of the stainless steel containers and aluminum barrels, filled with spent fuel elements, is presented to demonstrate that an adequate margin of subcriticality is proved for the reactor RA spent fuel storage.(author)