Author(s)

R. Baušys, G. Dundulis, R. Kačianauskas, R. Markauskas, S. Stupak & E. Ušpuras

Abstract

The floor response spectra of Ignalina nuclear power plant (NPP) containing RBMK-1500 type multi-channel graphite-moderated water-cooled reactors are investigated. The building structure of Ignalina NPP is characterized by structural elements with different stiffness properties, resulting in a complex mixed structure. For this reason an accurate and detailed three-dimensional model was considered. The seismic input presents two cases of vertical and horizontal design basis ground response spectra with 2% of critical damping. The free-field ground response spectra is obtained on the basis of the latest seismic data and properties of geological section of Ignalina NPP site, while two-dimensional finite element (FE) soil-structure interaction analysis was carried out in order to assess the effects on the input spectra. The floor response spectra of the NPP structures are calculated by applying a three-dimensional FE model. Assessment of the acceleration floor response spectra is made at the drum-separator support level. Comparison of the results of the 3D FE analysis with the results of the simplified \“stick” one-dimensional column discrete-mass model is also provided. Keywords: nuclear power plant, seismic analysis, finite element method, floor response spectra. 1 Introduction The Ignalina NPP located in Lithuania, close to the borders of Belarus and Latvia, contains multi-channel graphite-moderated water-cooled so-called

Keywords

nuclear power plant, seismic analysis, finite element method, floor response spectra.