Level 1 External Events (Internal Fire, Internal Floodand Seismic Events) PSA Accident Sequence Quantificationfor Point Lepreau Refurbishment Project

摘要

A Probabilistic Safety Assessment (PSA) for Point Lepreau Generating Station has beenrncompleted as part of the plant Refurbishment Project. The main objective is to provide insights intornplant safety design and performance, including the identification of dominant risk contributors and therncomparison of options for reducing risk. The scope of this assessment covers Level 1 and 2 PSA andrnincludes internal events for full power and shutdown, and internal fires, floods, and seismic events forrnfull power operation.rnInternal fire analysis established potential fire scenarios by identifying their fire characteristicsrn(ignition sources, combustibles, fire protection features, and location of PSA-credited components).rnThe fire-induced severe core damage frequency (SCDF) was estimated for fire scenarios that were notrnscreened out. Internal flood analysis established potential flood scenarios by identifying the floodingrnsource, propagation, and effect on PSA-credited equipment. The flood-induced SCDF was estimatedrnfor each flood scenario. PSA-based seismic margin assessment measured the robustness of the plantrnto withstand earthquakes of a given g-level.rnThis paper describes the major steps in performing Level 1 ASQ for internal fire, flood, and seismicrnevents and discusses the key results of this study.