Structural analysis of CSB and LSS for APR1400 RVI CVAP

•Structural analysis for LSS and CSB of APR1400 were conducted to verify their integrity.•CSB and LSS have sufficient integrity compared to the design acceptance criteria.•CSB and LSS can be excluded from measurement of APR1400 RVI CVAP. The study of the integrity of reactors has become an important aspect regarding the safety of nuclear power plants. The US Nuclear Regulatory Commission Regulatory Guide (NRC RG) 1.20 requires a comprehensive vibration assessment program (CVAP) to be used when verifying the structural integrity of the reactor vessel internals (RVI) for flow-induced vibrations prior to commercial operation. However, few RVI CVAP studies have been published in research journals. An advanced power reactor known as the Advanced Power Reactor 1400 (APR1400) RVI CVAP was classified as a non-prototype category 2 type of reactor as part of an independent validation of its design. The aim of this paper is to present the results of structural response analyses of the core support barrel (CSB) and the lower support structure (LSS) of the APR1400 reactor. These results demonstrate that the CSB and the LSS have sufficient integrity compared to the design acceptance criteria. The results also show that these structures can be excluded from the vibration and stress measurement program of the APR1400 RVI CVAP.