COVID-19 pandemic is an emergency that spread across the planet. It threatens lives and health of the population, with many dead and injured. Also, during pandemic there was (and continues to be) a violation of normal living conditions, significant material damage to economies of different countries. Quarantine restrictions affected social, educational, cultural and spiritual spheres of society. There is an urgent threat to operation of critical infrastructure as the pandemic led to large numbers of hospitalized or self-isolated people and being treated at home. At present, the operation of critical infrastructure, and in particular nuclear power plants, is strategically important for the proper functioning of any country. Also, the research describes causes of emergencies at nuclear power plants and identifies another factor - the mass disease of NPP personnel or their relatives on COVID-19. It is determined that timely detection and appropriate work to restore mental health during the pandemic is no less important area of work along with providing medical care to population. Stress associated with uncertainty, threat to health, can have negative consequences for well-being and mental health of workers. Depression, emotional exhaustion, anxiety, irritability, suicidal thoughts, etc. can also be consequences. Socio-psychological support especially for critical infrastructure workers is important to promote mental health during COVID-19 pandemic. Recommendations for socio-psychological support of NPP personnel were developed. Specialized mobile applications are described as convenient and economical way for primary psychological care.