Search

For numerical analysis or shaking table tests of in-cabinet equipment, in-cabinet response spectrum (ICRS) is adopted as required seismic demand. Several kinds of simplified concepts are commonly u... more...

This study aims to establish ordinary seismic demands imposed on safety-related electrical instruments mounted in electrical cabinets (referred to as in-cabinet equipment) in nuclear power plants and to understand the basic characteristics of the dynamic responses for electrical cabinets. An existing cabinet used in the Maanshan nuclear power plant was adopted as a specimen for a shaking table test. The vibration responses and spectral amplification factors of the tested cabinet under different shaking intensity levels, as well as the variation of total mass and anchorage locations of additional weights attached to the cabinet, are studied and summarized in this study. The results of this preliminary study can contribute to developing a complete test plan for motor control centers in the Lungmen nuclear power plant in future studies. more...

According to the seismic risk assessment results presented in the Final Safety Analysis Report (FSAR) for a nuclear power plant in Taiwan, the failure of Residual Heat Removal (RHR) piping system occurs in both of the two accident sequences with the highest contributions for core damage. The seismic performance of RHR piping system depends on the capacity of its components, such as supports, flanged joints and reducers. For the need of seismic response-history analysis of RHR piping systems, we developed detailed numerical models of flanged joint and reducer using finite element analysis software (ABAQUS and SAP2000). The proposed finite element models were verified by the experimental results. The pure bending tests with four-point cyclic loading were conducted for sample flanged joint and reducer to investigate their mechanical behaviors. The displacement and rotation responses identified from the tests are in good agreement with the results of numerical analysis. A preliminary simplified model of flanged joints was also proposed in this study to improve the efficiency of numerical analysis for RHR piping system.Copyright © 2014 by ASME more...

In order to ensure the operation of nuclear power plants (NPPs) during and after earthquakes, an overall reevaluation of the seismic performance in NPPs is proceeding in Taiwan. The issue of in-cabinet relays within cabinets is focused due to their importance for safety function and unstable seismic capability. To explore the rationality of general adopted seismic evaluation methods for in-cabinet relays, in-cabinet response spectrum (ICRS), the seismic demand on in-cabinet equipment, was studied through shaking table tests of the typical motor-control-center (MCC) type cabinets in NPPs. A simplified numerical method is proposed based on the observation of shaking table test results. The global modes were simulated by a lumped-mass model, and local modes were simulated by a detailed finite element model of the plate at which in-cabinet equipment is anchored. The ICRS and in-cabinet amplification factors (AF) estimated by the proposed method were discussed by the comparison with the shaking table test results, the frequency domain analysis (FDA) based on EPRI NP-7146-SL Report, and the complete finite element model of the cabinet. From above observation, the proposed model can predict global and local cabinet behaviors better in contrast to the FDA results, but cannot fit the local cabinet behavior very well. Future research effort will be to improve the proposed method to overcome the underestimate of the local behavior and other unexpected higher frequency response. more...