Identification and selection of initiating events for experimental fusion facilities

The current approaches used in probabilistic risk assessment (PRA) to identify and select accident-initiating events for study in either probabilistic safety analysis or PRA are described. The methods directly apply to fusion facilities as well as other types of industries, such as chemical processing and nuclear fission. These identification and selection methods include the master logic diagram, historical document review, system-level failure modes and effects analysis, and others. A combination of the historical document review (such as safety analysis reports and fusion safety studies) and the master logic diagram with appropriate quality assurance reviews is suggested for standardizing US fusion PRA efforts. A preliminary set of generalized initiating events derived from safety document reviews and applicable to fusion facilities is presented as a framework to start from for the historical document review and master logic diagram approach. Fusion designers should find this list useful for their design reviews.<>