Effect of slab stiffness on floor response spectrum and fragility of equipment in nuclear power plant building

• Published in: Nuclear engineering and technology Vol. 55; no. 11; pp. 3956 - 3972
• Main Authors: Lee, Yousang, Kim, Ju-Hyung, Park, Hong-Gun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2023; Elsevier; 한국원자력학회
• Subjects: Anchorage; Finite element model; Floor response spectrum; Nuclear power plant; Seismic fragility; 원자력공학; Anchorage; Finite element model; Nuclear power plant; Seismic fragility; Floor response spectrum
• ISSN: 1738-5733; 2234-358X
• DOI: 10.1016/j.net.2023.07.010

The floor response spectrum (FRS) is used to evaluate the seismic demand of equipment installed in nuclear power plants. In the conventional design practice of NPP structure, the FRS is simplified using the lumped-mass stick model (LMSM), assuming the floor slab as a rigid diaphragm. In the present study, to study the variation of seismic response in a floor, the FRSs at different locations were generated by 3-D finite element model, and the response was compared to that of the rigid diaphragm model. The result showed that the FRS significantly varied due to the large opening in a floor, which was not captured by the rigid diaphragm model. Based on the result, seismic fragility analysis was performed for the anchorage of a heat exchanger, to investigate the effect of location-dependent FRS disparity on the high confidence low probability of failure (HCLPF).