Dynamic analysis of high-level waste storage tanks

Abstract

DOE “tank-farm” sites consist of a large number of underground high-level waste storage tanks (HLWST). Seismic analysis and design of HLWSTs requires proper evaluation of fluid-structure interaction and hydrodynamic pressure. Although simplified guidelines for such tanks are available, a rigorous analysis invariably necessitates detailed finite element modeling. A systematic step-by-step approach for dynamic analysis of a HLWST using ADINA fluid elements is presented here. Initially, an open liquid-filled cylindrical ground-supported tank model is set up and frequency analysis studies for different tank configurations conducted with displacement-based (D-fluid) and potential-based (P-fluid) elements. The results are compared with the available data. The procedure is then extended to analyze the response of the tank to E1 Centro 1940 earthquake ground history and results verified for displacements and hydrodynamic pressure. Although ADINA's P-fluid elements give more accurate frequencies and pressure distributions than D-fluid elements, they cannot be at present used for seismic loading. The D-fluid elements are shown to perform adequately for practical problems under consideration.