Prevention or Mitigation of Major Accident Hazards through Early Identification of Safety Critical Elements

The Safety Critical Elements (SCEs) concept is widely used in Europe, Australia and the Middle East with limited use in the US; however, the concept of SCE has not yet found its place in the US regulations for both offshore and onshore industries.

Safety of a facility can be considerably improved with the identification of SCEs as early as the Front End Engineering Design (FEED) phase to prevent or mitigate Major Accident Hazards (MAHs) that cause catastrophic consequences. During this phase, the MAHs and its associated prevention & mitigation barriers are identified at the Hazard Identification workshops using operator risk matrix and the regulatory guidelines. Preliminary selection of SCEs can be achieved through the development of BowTie diagrams for each MAH showing the cause, consequence and the prevention & mitigation barriers. Following the identification of SCEs, the Design Performance Standards are developed to provide key requirements, performance criteria and assurance activities associated with each SCE during design, whereas the Operational Performance Standards are developed to provide maintenance strategies for SCEs during operation.

Overall, early identification of SCEs and the rigorous execution of this process throughout design provide assurance in building a safer facility and easier maintenance of the SCEs achieving minimum acceptable performance throughout the operating life of the facility thereby preventing or mitigating MAHs.