Designing systems important for NPP safety is basing on fulfilling the demands of normative documents and ensuring the quality of soft- and hardware systems throughout the entire life cycle. The most critical tasks in ensuring the quality of soft- and hardware complex are the phase for the formation of demands for a designed or modifiable system and their consequent verification. An increase in demands for the quality of software (SW) for systems important for NPP safety at all phases of the life-cycle is associated with an increase in the complicity and functionality of the software and has led to the need to develop methods to justify the safety of the systems themselves and the software included in them. The paper discusses a method based on the construction of "safety functions," the implementation of which subsequently verified. This method is using in SW verification for upper-level systems of APCS and can be used to analyze cybersecurity, information, and fault tolerance of soft- and hardware systems.

Over the years, the maintenance of information necessary for control systems – information bases – has been a thorny issue being raised by both researchers’ and practitioners’ communities. These days, information bases of modern industrial computerized control systems are forced to be modified too often, so the process of maintenance is highly iterative and should be more accurately referred to as updating. The matter is an exceptionally high rate of arriving jobs that create real flows. In this situation, characteristics of job flows are becoming extremely important for designing and applying suitable updating tools and estimating timing budgets for updating. However, no appropriate law or model for job flow prediction is presently available. The article advises to take into account particular situations, or situational factors, to explain and forecast job flows. To advocate this idea, a brief review of situational factors affecting information systems is presented, and the most critical ones for information base updating are selected. As an example of putting the idea into practice, the results of the investigation of nuclear power plant upper-level control system information bases are presented, and the influence of situational factors is demonstrated.

The methodology of the optimal design of technical objects under parametric mixed uncertainty has been developed. The article proposes the model of optimal design within the framework of the chance theory for modeling systems with mixed uncertainty. As an example, we formalize and solve the problem of calculating the weight parameters of a passenger aircraft at the preliminary design stage under parametric mixed uncertainty.

For significant objects of critical information infrastructure, including nuclear facilities, methods for findings anomalies, malfunctions, and diagnostics, as well as operator information support systems (OISS), are playing an increasingly important role in order to increase safety and reliability of operation. One of the tasks to be solved within the framework of the OISS is the task of calculating technical and economic indicators (TEI) and its relation with ensuring the normal operation of NPPs. TEIs characterize the effectiveness, reliability, and longevity of power equipment during its operation. The conditions for optimal operation of nuclear power plants determined in the process of analyzing TEIs. Therefore, the analysis of indicators is one of the essential tasks of the automated process control system of nuclear power plants. The informational task of TEIs in real-time based on data mining and forecast models of the risk potential of the critical infrastructure of the facility will allow operational personnel to take measures in advance to prevent the technological process from exceeding permissible operating limits.

We propose a model of opinion dynamics in social networks. Within the framework of the model, two interconnected processes––the excitation of network agents and the formation of their opinions––are studied. We demonstrate that, under certain conditions, this model preserves the differences in the agents’ opinions and even leads to their polarization.