Numerical Investigation of Postulated Steam Generator Tube Rupture Accident in a Lead-Cooled Fast Reactor

Abstract Because of the unique design of Lead-cooled Fast Reactor (LFR), the steam generator tubes containing high-pressure water is placed directly in the high temperature lead pool, therefore once a steam generator water tube ruptures during operation, the high-pressure subcooled feed water would interact directly with hot lead, giving rise to Steam Generator Tube Rupture (SGTR) accident, which is one of the accident scenarios that must be considered during LFR design and safety analysis process. Focused on this topic, numerous experimental and theoretical research have been conducted in recent decades. In this study, the Eulerian multiphase analysis code ACENA was applied to simulate the postulated SGTR accident of European pool-type lead-cooled fast reactor ALFRED. Attention was paid to the simulation results of safety parameters, such as the evolution history of maximum cladding and fuel temperature, core relative power, core void fraction and cover gas pressure; the migration process of steam bubbles was visualized as well. Furthermore, the sensitivity of model ruptured tube quantities and neutronic feedback models were also analyzed. This study could provide reference for LFR design and safety analysis work.