Application of Fluid-Structure Interaction for Steam Generator Force Analysis

The classical manner of analyzing the loss-of-coolant accident hydraulic loads imposed on a Westinghouse-type steam generator was to assume a primary side outlet break and to assume that the confining structure was rigid. By considering the vertical divider plate to be flexible, it can be shown that the applied hydraulic forces on the divider plate, tubesheet, and tubes are significantly reduced. The assumption of a flexible divider plate requires the interaction of the fluid and structure simultaneously. The MULTIFLEX computer program and system model have the capability of considering this mutual interaction. Results have been obtained showing the reasons why and how the hydraulic loads on the steam generator internals are attenuated.