It is noted that the requirements for the reactor installations of new atomic icebreakers of 22220, 10510, 10570 projects suggest an increase in safety (reliability), efficiency and maneuverability. At the same time, the maneuverability of reactor installations in specific features is limited and does not have an unambiguous connection with the maneuverability of the nuclear energy installation in general and rowing electric motors in particular. For this, the separate principle of controlling the reactor and steam turbine installation is implemented on the projects of atomic icebreakers. It is indicated that the development of new projects of atomic icebreakers with increased consumer properties requires processing the statistical information based on the results of the operation of atomic icebreakers of already implemented 10520, 10521, 10580 projects with various input terms and the duration of operation in the Arctic. This allows us to ensure the development of a reasonable approach when determining the operation of atomic icebreakers. It is noted that in order to compare maneuvering operating modes of reactor installations of individual icebreakers and the development of generalizing characteristics, information obtained from specific icebreakers is required. The collection of statistical data from the organized on all nuclear icebreakers and grouped materials are annually received for processing and generalization in the «OKBM Africantov». Assignment calculations are made on statistical information accumulated from 1975 to 2000 by the quantity and depth of change in reactors power when working in the Arctic conditions. A new approach to taking into account the number of equivalent cycles during maneuvering the reactor installation is proposed in the paper. In features of the existing approach with the determination of the above number of cycles in a new approach, the significance of the sublayer is taken into account by the impact on the reliability of the active zone. It is shown that this approach gives a more adequate assessment of the active zone resource expenditure during the campaign. The evaluation of the cycles density of the reactor installation power changing over the reporting period of time is also proposed. It is shown that at maneuverable operation of individual icebreakers there are an individual emphasis and increased maneuverable load of single-reactor icebreakers in relation to dual-reactor.