title: Structural safety analysis based on seismic service conditions for butterfly valves in a nuclear power plant.
abstract: The structural integrity of valves that are used to control cooling waters in the primary coolant loop that prevents boiling within the reactor in a nuclear power plant must be capable of withstanding earthquakes or other dangerous situations. In this study, numerical analyses using a finite element method, that is, static and dynamic analyses according to the rigid or flexible characteristics of the dynamic properties of a 200A butterfly valve, were performed according to the KEPIC MFA. An experimental vibration test was also carried out in order to verify the results from the modal analysis, in which a validated finite element model was obtained via a model-updating method that considers changes in the in situ experimental data. By using a validated finite element model, the equivalent static load under SSE conditions stipulated by the KEPIC MFA gave a stress of 135 MPa that occurred at the connections of the stem and body. A larger stress of 183 MPa was induced when we used a CQC method with a design response spectrum that uses 2% damping ratio. These values were lower than the allowable strength of the materials used for manufacturing the butterfly valve, and, therefore, its structural safety met the KEPIC MFA requirements.
authors: Department of Mechanical Engineering, Dong-A University, Busan 604-714, Republic of Korea.
authors: Sang-Uk
authors: SU
authors: Han
authors: Department of Mechanical Engineering, Dong-A University, Busan 604-714, Republic of Korea.
authors: Dae-Gyun
authors: DG
authors: Ahn
authors: Department of Mechanical Engineering, Dong-A University, Busan 604-714, Republic of Korea.
authors: Myeong-Gon
authors: MG
authors: Lee
authors: Department of Mechanical Engineering, Dong-A University, Busan 604-714, Republic of Korea.
authors: Kwon-Hee
authors: 0000-0001-6188-8662
authors: KH
authors: Lee
authors: Department of Mechanical Engineering, Dong-A University, Busan 604-714, Republic of Korea.
authors: Seung-Ho
authors: 0000-0002-2698-8366
authors: SH
authors: Han
mesh_terms: D020342:Finite Element Analysis; D008962:Models, Theoretical; D055848:Nuclear Power Plants