Background. The relationships between conceptual model structures and an operator's professional efficiency are of direct practical importance, particularly in the case of large-scale industrial complexes combining several human-machine systems. A typical example is the power unit of a nuclear power plant (NPP). objective and methods. The purpose of this study was to explore the conceptual models of senior reactor operators (SROs) of NPPs. The study involved 64 men working as SRO at five NPPs in Russia. The methods included: structured interviews, expert estimations, multidimensional scaling (ALSCAL), the K-means clustering algorithm, and frequency analysis. The procedure was as follows: 32 key characteristics of the power unit were defined, including shift operators' jobs and duties, technical subsystems, types of equipment, and the crucial power unit parameters. The participants were offered a 32 × 32 matrix for pair-wise estimation of the strength of the links between these key characteristics on a seven-point scale (496 links in total). Results. A general scheme of key characteristics in the conceptual models was defined. This scheme was displayed in the operators regardless of their employment history. Within the scheme, however, two types of conceptual models were identified, which could be distinguished by the relative number of strong links between the key characteristics. With respect to intersystem links including key characteristics of the reactor and turbine NPP departments, this number was significantly higher in models of Type 1 than in those of Type 2. A positive correlation between the number of these links and the professional efficiency indicators was also established. Operators with Type 1 models were able to more predictably represent the power unit operation. conclusion. The main role in creating predictable and efficient conceptual models was played by strong intersystem links in mental representations of workflow.

Background. The relevance of the study is determined by the search for the determinants of the subjective professional well-being of operators. Possibilities of operators’ trust in equipment for achieving subjective professional well-being (SPWB) are considered. Objective. The analysis of the features of manifestation of operators’ trust in equipment as a psychological resource of subjective professional well-being was carried out. Design. The author’s questionnaire “Trust of the specialist to equipment (TSE)” was used to diagnose the level of trust of operators in equipment. Questionnaires: “Social and professional demand for personality”, “Methods for assessing professional well-being”, “Dominant state”, “Passionate about work” were used to diagnose SPWB. Empirical data were translated into z-scores. Z-scores were subjected to multidimensional scaling (non-metric scaling, distance function — Euclidean distance). The results were displayed in the form of two-dimensional graphic models of the psychological space of SPWB. In the SPWB space, assessments of indicators of operators’ trust in equipment and subjective professional well-being were reflected. Research sample. The study involved 76 NPP operators (specialists), 100 locomotive driver — a total of 176 people. Work experience — from 1 to 35 years. Results. The level of trust in the equipment among specialists is higher than among the locomotive drivers — 75.8 points and 62.4 points, respectively (p < 0,001). Experts’ assessments of indicators of trust in the equipment are located on the border of the SPWB space, far from the assessments of SPWB indicators. For locomotive drivers, assessments of indicators of trust in the equipment are located within the SPWB space next to 4 indicators of the SPWB. They reflected the desire for professional growth, satisfaction with the level of competence and professional achievements, the state of passion for work. Conclusions.The trust of specialists in the equipment becomes a psychological resource of subjective professional well-being in critical working situations. The trust of locomotive drivers in the equipment is a constant psychological resource for maintaining subjective professional well-being.