PROBABILISTIC SAFETY ANALYSIS IN CHEMICAL INSTALLATIONS

A set of procedures and corresponding methodologies for probabilistic safety assessment (PSA) in chemical installations is presented. State-of-the-art methodology for PSA in nuclear power plants is tested for suitability and applicability to chemical installations and applied on a refrigerated ammonia storage facility. The procedural steps comprise hazard identification, accident sequence modelling, data acquisition and parameter estimation, accident sequence quantification, hazardous substance release categories assessment, consequence assessment and integration of results. The results of the application indicate that the methodology applied is adequate from the procedural and completeness point of view and that no major aspect of PSA of a chemical installation is overlooked. A need for integrated computerized tools has, however, been identified.