Publisher Summary This chapter focuses on radioactive waste that can be generated by some activities. The waste can be classified according to its radioactivity level and decay time. These two characteristics principally influence the choice of the best method for waste treatment and its storage or disposal. A classification can be internationally used with the management method. The quantity of radioactive waste can be produced by the various activities. A disposal system can be replaced by more elaborate methods, based on the acknowledgement of the importance of introducing redundancy in the safety systems. This approach substantially aims at designing the storage with the concept of entrusting safety to various natural and artificial components. Each component represents a barrier to the diffusion of radionuclides into the biosphere. In the near surface type, the disposal structures can be positioned above or below ground. Produced radioactive waste releases large quantities of heat. The spent fuel becomes an energy resource in the future. Temporary storage is a way of buying some time.