The objective of this study is to analyze the modalities of health crisis management in two different sectors during the Covid-19 crisis: the hospital and the nuclear industry. The aim is to:- Characterize the health crisis: similarities and differences compared to other known crises - nuclear, natural crisis (storm, earthquake, flood). - Identify elements of similarity between sectors in the modalities of crisis management and particularities related to the specificities of the socio-technical systems.- Identify the resilience factors and difficulties- Make proposals to enhance the robustness of crisis organizations.Study BackgroundBoth the hospital and the nuclear industry (EDF) have had to organize and adapt to continue their activities from the beginning of the crisis in March 2020.On the hospital side, an emergency plan (White Plan) provides a reconfiguration of the hospital in case of health crisis. On the nuclear side, a Business Continuity Plan exists as well as a pandemic emergency plan (support and mobilization plan).It was at La Pitié Salpêtrière Hospital, a reference hospital for infectious diseases, that the first death of Covid19 was recorded. The crisis unit was activated at that time. The hospital then opened its doors to us for human and organizational factors study of crisis management in April 2020. Concerning the nuclear sector, the health crisis management analysis could only be carried out from October 2020 at the national level and the nuclear power plants.Methodological approachWe applied a systemic approach combining ergonomics, cognitive psychology, and sociology to study socio-technical systems safety.The study focused on crisis management via an analysis of organizational resilience to identify the factors of success and difficulty. Given the temporality of this crisis, the study was carried out in three stages at the hospital.1. April and May 2020: i) a series of remote interviews with various hospital staff were conducted; ii) a passive listening follow-up of about 30 phone meetings of the crisis unit; iii) a documentary analysis of the planned crisis organization.2. November and December 2021: i) a second series of interviews in the hospital emergency unit.3. June and July 2021 in the intensive care unit: i) a third round of interviews; ii) field observations in the hospital; iii) a literature review.In the nuclear field we conducted two retrospective studies at different times, focused on the most critical phase of the crisis (from March to May 2020):1. October - November 2021: an analysis of the health crisis’ management at the national level via a series of interviews completed by an analysis of the crisis reference systems.2. August - September 2021: an analysis of the health crisis management in a Nuclear power plant via interviews and an analysis of site-specific documents. ResultsWe observed similarities in the way the crisis was managed, in terms of management, which proved to be factors of success both at the hospital and at EDF, for example,- A crisis management that integrates the business lines and is top-down, but that listens and takes into account proposals from the field.- Experience of crises and emergency situations, which facilitates crisis management and adaptation.- The habit of protocols facilitating the integration of new constraints.- Very strong collective mobilization of personnelHowever, there are linked difficulties in both sectors, for example, to the virus fear, the anxiety of contaminating one's family and friends, especially at the beginning, and then weariness and fatigue linked to the duration of the crisis.Particularities concerning the work activity in the hospital will be discussed especially in relation to the reconfiguration of the services and to the necessary adaptations and improvisations of patients care protocols and procedures, among others.These studies are source of learning, about crisis management and particularly long-term crises that have a lasting impact on socio-technical systems. Proposals in terms of crisis organization and preparedness for this type of crisis will be presented.