INTEGRITY OF A CURVED DIVIDER PLATE IN STEAM GENERATORS OF PRESSURIZED WATER REACTORS DUE TO DYNAMIC PRESSURE LOADING CONSIDERING FLUID STRUCTURE INTERACTION

摘要

A non-linear analysis procedure has been developed to investigate the plastic behavior of the divider (or partition) plate in Steam Generators (SG) of Pressurized Water Reactors (PWRs). The integrity of the divider plate in the primary channel head of a Steam Generator of a Pressurized Water Reactor has to be verified for a postulated loss of coolant accident (LOCA). Primary stresses due to differential pressure Δp have to be analyzed for faulted conditions. A static elastic-plastic finite element analysis for the divider plate was performed showing unrealistically high plastic deformation due to the high differential pressure loading resulting from the assumption of rigid walls in the fluid analysis. Therefore the LOCA is analyzed in a Fluid Structure Interaction Analysis (FSIA), representing the divider plate as a single degree of freedom system (SDOFS) acting like a piston. The present paper explains how the Δp across the plate was correlated with an equivalent displacement v_e and how the mass of the plate is considered. In the FSIA a realistic dynamic response of the divider plate is considered now, with a significant reduction of differential pressure Δp. The analysis results proved the resistance of the divider plate with sufficient margin.