Risk assessment of a complex system that uses new technologies is described: the MegaJoule Laser (LMJ). The steps to obtaining the safety and security goals for LMJ are highlighted, i.e., to ensure safe operation, to put in place detection systems and means to prevent or limit serious accidents, and to limit the consequences to the environment and the workers. The objective is to show what has been done during LMJ design and construction to prevent serious accidents during routine operations and maintenance.

The risks during operations and maintenance of the LMJ facility are identified by a preliminary risk analysis. The safety management to address adequately the protective features is described. As an example, a main accidental scenario in the LMJ target area is emphasized: workers' exposure to hazardous levels of nuclear radiation. The LMJ operation and maintenance safety requirements that must be taken into account by the industrial firms to which LMJ contracts have been awarded are discussed.