scholarly journals Issues of the Seismic Safety of Nuclear Power Plants

10.5772/65853 ◽  
2017 ◽  
Author(s):  
Tamás János Katona
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Seismic Safety

Study on Dynamic Strength Evaluation Method of Mechanical Members Based on Energy Balance

2007 ◽  
Author(s):  
Keisuke Minagawa ◽  
Satoshi Fujita ◽  
Seiji Kitamura ◽  
Shigeki Okamura
Keyword(s):  
Energy Balance ◽  
Experimental Model ◽  
Ultimate Strength ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Dynamic Strength ◽  
Input Energy ◽  
Seismic Safety ◽  
Strength Evaluation

This paper describes the dynamic strength evaluation of piping installed in nuclear power plants from a viewpoint of energy balance. Mechanical structures installed in nuclear power plants such as piping and equipment are usually designed statically in elastic region. Although these mechanical structures have sufficient seismic safety margin, comprehending the ultimate strength is very important in order to improve the seismic safety reliability in unexpected severe earthquakes. In this study, ultimate strength of a simple single-degree-of-freedom model is investigated from a viewpoint of energy balance equation that is one of valid methods for structural calculation. The investigation is implemented by forced vibration experiment. In the experiment, colored random wave having predominant frequency that is similar to natural frequency of the experimental model is input. Stainless steel and carbon steel are selected as material of experimental model. Excitation is continued until the experimental model is damaged, and is carried out with various input levels. As a result of the experiment, it is confirmed that input energy for failure increase with an increase of time for failure. Additionally it is confirmed that input energy for failure depend on the material.

Innovative seismic resistant structure of shield building with base isolation and tuned-mass-damping for AP1000 nuclear power plants

2019 ◽  
Vol 36 (4) ◽  
pp. 1238-1257 ◽  
Author(s):  
Gangling Hou ◽  
Meng Li ◽  
Sun Hai ◽  
Tianshu Song ◽  
Lingshu Wu ◽  
...  
Keyword(s):  
Nuclear Power ◽  
High Performance ◽  
Seismic Isolation ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Base Isolation ◽  
Risk Mitigation ◽  
Design Parameters ◽  
Seismic Safety ◽  
Content Type

Purpose Seismic isolation, as an effective risk mitigation strategy of building/bridge structures, is incorporated into AP1000 nuclear power plants (NPPs) to alleviate the seismic damage that may occur to traditional structures of NPPs during their service. This is to promote the passive safety concept in the structural design of AP1000 NPPs against earthquakes. Design/methodology/approach In conjunction with seismic isolation, tuned-mass-damping (TMD) is integrated into the seismic resistance system of AP1000 NPPs to satisfy the multi-functional purposes. The proposed base-isolation-tuned-mass-damper (BIS-TMD) is studied by comparing the seismic performance of NPPs with four different design configurations (i.e. without BIS, BIS, BIS-TMD and TMD) with the design parameters of the TMD subsystem optimized. Findings Such a new seismic protection system (BIS-TMD) is proved to be promising because the advantages of BIS and TMD can be fully used. The benefits of the new structure include effective energy dissipation (i.e. wide vibration absorption band and a stable damping effect), which results in the high performance of NPPs subject to earthquakes with various intensity levels and spectra features. Originality/value Parametric studies are performed to demonstrate the seismic robustness (e.g. consistent performance against the changing mass of the water in the gravity liquid tank and mechanical properties) which further ensures that seismic safety requirements of NPPs can be satisfied through the use of BIS-TMD.

Innovation structure combining inter-story isolation with passive cooling effect for AP1000 nuclear power plants

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gangling Hou ◽  
Yu Liu ◽  
Tao Wang ◽  
Binsheng Wang ◽  
Tianshu Song ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Cooling System ◽  
Design Method ◽  
Passive Cooling ◽  
Original Design ◽  
Seismic Safety ◽  
Lower Altitude ◽  
Content Type

PurposeAn inter-story isolation structure (IIS) for AP1000 nuclear power plants (NPPs) is provided to resolve the conflict of seismic safety and the optimal location of air intakes.Design/methodology/approachThe effect of passive cooling system (PCS) is better with lower altitude of air intakes than that in the original design of AP1000 NPPs. Seismic performances of IIS NPPs, including the seismic responses, damping frequency bandwidth and seismic reduction robustness, are improved by combining the position of air intakes lower and the optimal design method.FindingsTheoretical analysis and numerical simulation are illustrated that the seismic reduction failure of IIS NPPs is the lowest probability of occurrence when PCS has highest working efficiency.Originality/valueThe IIS NPPs can transfer the contradiction between PCS work efficiency and seismic safety of NPPs to the mutual promotion of them.

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