Supervision applied to nuclear fuel reprocessing

Model-based supervision developed by systems analysts has become an acknowl edged supervision aid, ensuring early detection of malfunctions and thereby allowing control of the availability and vulnerability of a process facili ty. However, it is associated with diagnostics of the process itself, and n ot of the process control situation, which is the veritable subject of supe rvision. The operator, facility, control triplet determines a complex situa tion that must be considered from multiple viewpoints beyond knowledge of t he single behavioral model usually advocated in process control approaches. Representing different aspects of process control situation from multiple viewpoints notably allows the on line selection of the behavioral models re levant to the observed situation. Given the size of the application, it was essential not only to structure the knowledge required for the supervision system functions into operating system viewpoints, but also to provide a u nique representation method for each viewpoint. The systemic approach SAGAC E provides this formal representation framework and the methodology adopted to design and implement our industrial prototype relies on it. All these p rinciples are illustrated by a description of an industrial application in the area of nuclear fuel reprocessing: the size and complexity of the facil ities and their high degree of computerization make reprocessing particular ly well suited for supervision applications.