[en] This paper shortly summarizes some problems to be taken in consideration for the application of the ICRP optimization techniques to the design of nuclear facilities in order to minimize radiation exposure during the decommissioning phase. Then are examined the relevant factors in decommissioning from the point of view of radiation protection: the activation of structural materials, the dismantling and decontamination techniques, the radioactive waste. Some considerations on recycling-restricted-unrestricted use of materials and on the relationship between normal operation and decommissioning affecting the occupational exposure, are presented