Risk-based precursor analysis essentially consists of the mapping of an operational event — this is a safety-related incident that occurred in an industrial installation like a nuclear power plant (NPP) — on a risk model of the installation. This risk model might be a full probabilistic safety analysis (PSA), which is available now for all NPPs. The analyses may result in a more objective risk ranking of safety-significant events, called accident precursors, as to their possible consequences. By asking what-if questions, the study might also involve still other potential accident scenarios, based on the real scenario as it happened, to...