[en] As about sixty criticality accident have been listed since 1953, mainly in the USA and in the ex-USSR, this report first proposes an overview of criticality risks in the nuclear industry: they concern installations related to fuel cycle as soon as significant quantities of fissile materials are handled. It evokes the consequences of an uncontrolled chain reaction in terms of radiations, presents the concept of criticality and its measurement unit, and outlines the importance of an analysis of these accidents. It describes the role of IRSN in the management of criticality risks. It proposes an assessment of criticality accidents which occurred in research reactors or laboratories on critical assemblies, and in laboratories and installations related to fuel cycle. These accidents are presented in tables containing different information: date, site, exposures, number of fissions, accident history, characteristics of the fissile material, abstract of presentation of the accident. A second part of the document proposes an update of the first one, and also reports experiments of criticality performed by the IRSN