Leonova, E.V.

Background. To substantiate the reliability assessment of the operating personnel at a nuclear power plant (NPP) under conditions of increasing load, it is necessary to specify the existing general patterns of the functional state dynamics depending on the work and sensory load in relation to the specifics of the work of the NPP operator.

Objective. The aim is to determine the influence of psychophysiological reliability on the probability of errors in NPP operating personnel.

Study Participants. The operational personnel of the nuclear power plant consisting of 40 men.

Methods. Methods for assessing functional state indicators were applied using the hardware and software complex of the Electronic Health Monitoring System. Timesheet analysis, as well as the analysis of the number of general, working and emergency signals during shifts were conducted. Methods of statistical data analysis involved the Statistica statistical package and Excel spreadsheets: descriptive statistics, assessment of the distribution of features, data standardisation; ANOVA and post-hoc analysis (η2p, Tukey HSD).

Results. It was found that the probability of errors made by operational personnel was more closely related to the indicators reflecting the functional state than to the characteristics of the workload. Of these, the probability of mission is more closely related to the indicators of states and the influence of sensory load. The probability of an Erroneous Response is related to both the functional state and a large number of workload factors. The influence of the level of sensory load on the functional state of the operator was also established. A low level of sensory load allows maintaining optimal reaction time and adaptation to work activity for up to 5 working days. An average level of sensory load reduces the duration of the optimal performance period, while a high sensory load causes excessive activation and an increase in mental stress even on the first work day.

Conclusions. Four consecutive uninterrupted work days are the critical duration of uninterrupted work that does not affect the functional state of the operator. From the fifth day, accumulated fatigue significantly affects the reaction speed indicators, and most importantly, the degree of conscious control of the reaction. By the eighth day, compensatory functional reserves are depleted. The direction of future research is the analysis of the influence of methods of psychological and psychophysiological support of the functional reliability of workers, developed in the NPP’s psychophysiological laboratories.