We have considered the strategic approach to solving large-scale multidisciplinary problems, the features and methodology of the key procedures of project-oriented planning. The sequence of such planning stages and the specifics of each stage are illustrated by the example of developing a strategic plan to solve one of the most difficult problems in the field of radiation safety, which is the Strategic Master Plan (SMP) for Recycling and Environmental Rehabilitation of decommissioned nuclear fleet and service infrastructure in the North-West region of Russia. We have provided data on the status of this problem for the time when the functions of the state customer and coordinator of work were transferred to the Ministry for Atomic Energy of the Russian Federation. We have presented the main results of the current development and implementation of the SMP, outlining directions for further possible application of the strategic planning methodology in the field of radiation safety.