One of the areas of occupational medicine is organizing the pre-shift medical examination of personnel of hazardous and extrahazardous industrial facilities, such as nuclear power plants. Appropriate medical control is not only permanent, but practically integrated into the technological process. The introduction of digital technologies at the stage of medical examination makes it possible to increase the efficiency of activities, reduce labour costs and opens up new opportunities for the constant accumulation of relevant information about the individual parameters of the employees' health status. The article analyzes the "digital twin" concept, substantiates the possibility of using the "Prognoz" [Forecast] hardware and software complex, used during preshift medical examinations, when creating digital copies of a nuclear power plant operator, discusses the development of individual criteria for permit to work according to the results of pre-shift control based on digital personal data processing. Digital twins of operators, which are in constant communication with their prototype, can be useful not only for ensuring the safety of nuclear industry production, but also when providing routine medical care, considering individual parameters of the employees' health status in the amount of the information collected. This approach makes it possible to form both digital twins of individual employees and digital twins of collectives (for example, entire shifts) with the subsequent formation of recommendations of both current and prognostic nature.