Hazards/Compound and Cascading Hazards
Compound and Cascading External Hazards
Compound and cascading hazards arise when two or more external events affect a nuclear power plant simultaneously, sequentially, or through causal linkage. Industry practice distinguishes three categories: consequential hazards (one event triggers another), correlated hazards (a common cause produces simultaneous effects), and coincidental hazards (unrelated events overlap in time). Combined events can simultaneously challenge multiple plant functions, producing consequences qualitatively different from and more severe than any single event. The 2011 Fukushima Daiichi accident demonstrated the catastrophic potential of cascading hazards.
Return to Hazards. | EPRI technical point of contact: Chris Rochon (CRochon@epri.com)
Date last reviewed: 2026-05-07