In the aftermath of recent terrorist attacks in Europe, high-risk industries have dramatically increased their investments in security enhancement. Security technologies such as fences, infra-red security cameras, fingerprints recognition systems and security processes like access control procedures and the “four eyes” principle have emerged, thereby disrupting these industries’ traditional modes of functioning. Whereas these organizations originally focused almost entirely on production and safety stakes, they now pay increasing attention to security. Topics such as terrorism, drones attacks, insider threats, cyber criminality are gaining traction. However, such tremendous evolutions impact safety-oriented policies, technologies, values and behavior. This research presents results of an examination of the significant increase of security technologies and processes (called here materialities) implementation, and their impacts within a Belgian nuclear research center. Drawing on qualitative methods (interviews, focus groups and ethnographies), it analyzes the basic assumptions and values that inform these security technologies and processes. Secondly, it examines how they participate to shape the sociotechnical imaginaries as well as counter-imaginaries (such as safety imaginaries). It mobilizes the idiom of co-production and the concept of technological cultures to comprehend how security and safety imaginaries and materialities are mutually constituted. Practically, it permits to get a better grasp on the impacts such processes or technologies might have on security imaginaries as well as on other ones.