Human Performance and Reliability in a Complex Seismic Accident Scenario at a Nuclear Power Plant

A scenario, where a nuclear power plant has experienced an earthquake, and lost its automation systems and main control room, is improbable but exceptionally severe.Then, the mission of the operators is to steer the plant to a safe and as stable as possible state, and secure residual heat removal.In this paper, the scenario is described.Factors affecting operator performance in the scenario are considered.A human reliability analysis model for the scenario is proposed, and its main features outlined.The model consists of treatment of timings and of human errors.Concerning timings, an activity network model is proposed.Concerning human errors, special features of the scenario are treated in performance shaping factors (PSF); central PSFs are identified and factors affecting them are described.