Johannes Schmidl, M. Pellissetti, Eugen Fütterer, R. Hilpert, A. Nykyforchyn, Sunay Staeuble Akcay
{"title":"Deterministic and Probabilistic Evaluation of Seismic Loads on RPV Internals including Nonlinear Effects","authors":"Johannes Schmidl, M. Pellissetti, Eugen Fütterer, R. Hilpert, A. Nykyforchyn, Sunay Staeuble Akcay","doi":"10.1115/1.4053753","DOIUrl":null,"url":null,"abstract":"\n The paper presents analytical results for the dynamic analysis of the control rod drive mechanisms (CRDM) and selected Reactor Pressure Vessel (RPV) internals, i.e. core barrel (CB) upper flange and upper core plate centering, as well as resulting stresses. The model for the dynamic analysis of the RPV Internals with CESHOCK consists of springs and lumped masses, combined with beam elements.\n The model is taking into account material nonlinearities, sliding, friction and gap/impact effects inside the RPV. Refined finite element modelling of contact regions is used to calibrate the force-displacement relationship used in the dynamic model.\n Both deterministic and probabilistic analyses are presented. The excitations are based on upstream time history (TH) analyses with a coupled model of the nuclear steam supply system (NSSS) and the reactor building. Variability of ground motion parameters (shear modulus and damping) and building parameters (Young's modulus and damping) is taken into account.\n The deterministic analyses confirm that the core barrel upper flange is the most highly stressed part of the RPV internals in case of seismic excitations.\n The probabilistic analyses show that there is a robust correlation between the spectral acceleration at the fundamental frequency of the core barrel and the maximum load on the core barrel flange. This is in agreement with one of the standard assumptions adopted for fragility analysis in the nuclear industry and is confirmed for the core barrel flange in the present analysis.","PeriodicalId":50080,"journal":{"name":"Journal of Pressure Vessel Technology-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":1.0000,"publicationDate":"2022-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Pressure Vessel Technology-Transactions of the Asme","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1115/1.4053753","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The paper presents analytical results for the dynamic analysis of the control rod drive mechanisms (CRDM) and selected Reactor Pressure Vessel (RPV) internals, i.e. core barrel (CB) upper flange and upper core plate centering, as well as resulting stresses. The model for the dynamic analysis of the RPV Internals with CESHOCK consists of springs and lumped masses, combined with beam elements.
The model is taking into account material nonlinearities, sliding, friction and gap/impact effects inside the RPV. Refined finite element modelling of contact regions is used to calibrate the force-displacement relationship used in the dynamic model.
Both deterministic and probabilistic analyses are presented. The excitations are based on upstream time history (TH) analyses with a coupled model of the nuclear steam supply system (NSSS) and the reactor building. Variability of ground motion parameters (shear modulus and damping) and building parameters (Young's modulus and damping) is taken into account.
The deterministic analyses confirm that the core barrel upper flange is the most highly stressed part of the RPV internals in case of seismic excitations.
The probabilistic analyses show that there is a robust correlation between the spectral acceleration at the fundamental frequency of the core barrel and the maximum load on the core barrel flange. This is in agreement with one of the standard assumptions adopted for fragility analysis in the nuclear industry and is confirmed for the core barrel flange in the present analysis.
期刊介绍:
The Journal of Pressure Vessel Technology is the premier publication for the highest-quality research and interpretive reports on the design, analysis, materials, fabrication, construction, inspection, operation, and failure prevention of pressure vessels, piping, pipelines, power and heating boilers, heat exchangers, reaction vessels, pumps, valves, and other pressure and temperature-bearing components, as well as the nondestructive evaluation of critical components in mechanical engineering applications. Not only does the Journal cover all topics dealing with the design and analysis of pressure vessels, piping, and components, but it also contains discussions of their related codes and standards.
Applicable pressure technology areas of interest include: Dynamic and seismic analysis; Equipment qualification; Fabrication; Welding processes and integrity; Operation of vessels and piping; Fatigue and fracture prediction; Finite and boundary element methods; Fluid-structure interaction; High pressure engineering; Elevated temperature analysis and design; Inelastic analysis; Life extension; Lifeline earthquake engineering; PVP materials and their property databases; NDE; safety and reliability; Verification and qualification of software.