Seismic Response of a Cylindrical Water Storage Tank of Nuclear Power Plant

2018 ◽  
Author(s):  
Shinichi Matsuura ◽  
Ichiro Tamura
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Storage Tank ◽  
Nuclear Power ◽  
Water Storage ◽  
Response Behavior ◽  
Water Storage Tank ◽  
Elastic Plastic ◽  
Seismic Motion ◽  
Side Shell

It is important in the confirmation of the safety of the nuclear power plant to clarify the response behavior of a vertical cylindrical water storage tank under seismic motion. When a vertical cylindrical tank is shaken by a large earthquake, deformation of side shell due to the elephant foot buckling, the oval vibration etc. may occur. The occurrence of those deformations depends on materials, shapes, stored water level and time history of seismic motion. Then, response behavior was obtained for a condensate storage tank (CST) model under large seismic motion such as standard earthquake Ss multiplied by 2 with the elastic-plastic finite element calculation. In this calculation, dynamic water pressure and elastic-plastic characteristics of the material were taken into account. In this case, the elephant foot bulge did not occur but the oval vibration of side shell became dominant. Based on the result, we estimated the structural integrity of the tank.

Response Spectrum Analysis of the Condensate Storage Tank in a Nuclear Power Plant

2013 ◽  
Vol 284-287 ◽  
pp. 1421-1425
Author(s):  
Wei Ting Lin ◽  
Meng Hsiu Hsieh ◽  
Yuan Chieh Wu ◽  
Chin Cheng Huang
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Computer Model ◽  
Storage Tank ◽  
Nuclear Power ◽  
Soil Structure ◽  
Response Spectrum ◽  
Soil Structure Interaction ◽  
Storage Tanks ◽  
Structure Interaction

Following the nuclear power plant accident in Fukushima Japan, seismic capacity evaluation has become a crucial issue in combination building safety. Condensate storage tanks are designed to supplies water to the condensate transfer pumps, the control rod drive hydraulic system pumps, and the condenser makeup. A separate connection to the condensate storage tank is used to supply water for the high pressure coolant injection system, reactor core isolation cooling system, and core spray system pumps. A condensate storage tank is defined as a seismic class I structure, playing the important role of providing flow to the operational system and the required static head for the suction of the condensate transfer pumps and the normal supply pump. According to the latest nuclear safety requirements, soil structure interaction must be considered in all seismic analyses. This study aims to rebuild the computer model of condensate storage tanks in Taiwan using the SAP 2000 program in conjunction with the lumped mass stick model and to evaluate the soil structure interaction by employing the SASSI 2000 program. The differences between the results with the soil structure interaction and spring model are compared via natural frequency and response spectrum curves. This computer model enables engineers to rapidly evaluate the safety margin of condensate storage tank following the occurrence of earthquakes or tsunamis.

Analysis of Flowing Characteristics in IRWST Under Pressure Relief Condition

2013 ◽  
Author(s):  
Mengchao Zhang ◽  
Xiangbin Li ◽  
Xiaolu Fang ◽  
Yuhao Zhang
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Storage Tank ◽  
Nuclear Power ◽  
Water Storage ◽  
Heat Transfer Mechanism ◽  
Heat Transfer Characteristics ◽  
Pressure Relief ◽  
Water Storage Tank ◽  
Thermal Changes

The presurizer is one of main equipments of PWR Nuclear Power Plant. The heat transfer mechanism will change with temperature’s increasing when the steam with high temperature and high pressure condensates as it sprays into the in-containment refueling water storage tank (IRWST), which will be detrimental to the safety of the reactor. In this study, the flow field and heat transfer characteristics are simulated by means of professional CFD software with k-ε turbulence model and Particle modle when the steam sprays into IRWST through the sprayer. The results show thermal changes of water and steam.

Carbon Fiber Reinforcement of a Water Storage Tank for Beyond Design Basis Loads

2016 ◽  
Author(s):  
Alton Reich ◽  
John Charest
Keyword(s):  
Carbon Fiber ◽  
Storage Tank ◽  
Nuclear Power ◽  
Power Plants ◽  
Water Storage ◽  
Safety Margin ◽  
Repair System ◽  
Buckling Mode ◽  
Water Storage Tank ◽  
Design Basis

The severe damage to the Fukushima nuclear plant occurred as a result of a beyond design basis event. This has prompted a systematic review of safety critical systems at US nuclear power plants to evaluate the existing safety margin based on beyond design basis loads. At one US nuclear power plant it was found that the Refueling Water Storage Tank (RWST) did not have sufficient margin to withstand the defined beyond design basis seismic event. An analysis indicated that the RWST would fail in an elephant foot buckling mode. This paper describes the design and analysis of a Carbon Fiber Reinforced Polymer (CFRP) repair system used to strengthen the RWST to increase the critical buckling stress for the elephant foot buckling mode.

Design of In-Containment Refueling Water Storage Tank of Chinese 3rd Generation Nuclear Power Plant

2017 ◽  
Author(s):  
Liu Yulin ◽  
Sun Xiaoying
Keyword(s):  
Storage Tank ◽  
Nuclear Power ◽  
Power Plants ◽  
Water Storage ◽  
Stability Evaluation ◽  
Water Storage Tank ◽  
Structure Interaction ◽  
Structural Calculation ◽  
Structure Strength ◽  
The Stability

In this paper, the structure configurations of the in-containment refueling water storage tank (IRWST) of Chinese 3rd generation nuclear power plants (NPPs) was described firstly. Then, the general structural calculation for several loads, especially thermal load, were presented, as well as the stability evaluation of IRWST base-slab. The effect from fluid-structure interaction was also considered in the calculation to evaluate the design margin of IRWST. Finally, structure strength evaluation was performed for construction load case.

Analysis of Liquid Sloshing in an In-Containment Refueling Water Storage Tank for AP1000

2013 ◽  
Author(s):  
Yu Liu ◽  
Daogang Lu ◽  
Junjie Dang ◽  
Licun Wu ◽  
Wenhui Ma
Keyword(s):  
Storage Tank ◽  
Nuclear Power ◽  
Cooling System ◽  
Water Storage ◽  
Sine Wave ◽  
Liquid Sloshing ◽  
Normal Operation ◽  
Water Storage Tank ◽  
Core Cooling ◽  
Residual Heat

Although much work has been performed on the liquid sloshing inside simple structures like rectangular and cylindrical vessels, this paper deals with the analysis of the liquid sloshing in a more complex structures, the in-containment refueling water storage tank (IRWST). The IRWST is an important component of AP1000 passive core cooling system to ensure the safe operation of the AP1000 nuclear power plant. In postulated non-LOCA events, the water in the IRWST absorbs the residual heat then transfers the heat into the containment atmosphere. However, in the case of earthquake, the sloshing fluid may influence the safety of the appropriate semi-cylindrical IRWST. In this paper, the liquid transient response in the IRWST was formulated based on finite element modal analysis when the three resonance sine wave was applied as excitation. The result shows that the maximum wave excited by excitation from different directions always emerges from the corner or the edge of tank. Another finding is that water will not overflow at the normal operational water level when exited by the selected excitations in any directions. The safety of the IRWST’s roof is achieved which guarantees that the water vapor and radioactive gases within the tank during normal operation will not release to atmosphere in the containment. The influence of the excitation direction and the water depth are also analyzed.

Design of a Tornado Missile Resistant Shield for the Angra Nuclear Plant

2015 ◽  
Author(s):  
Alton Reich ◽  
Jason Moon
Keyword(s):  
Storage Tank ◽  
Nuclear Power ◽  
Power Plants ◽  
Water Storage ◽  
Environmental Hazards ◽  
Water Tank ◽  
Raw Water ◽  
Water Storage Tank ◽  
Design Basis ◽  
Under Construction

The Angra site contains the only two operational nuclear power plants in Brazil and one that is under construction. When Angra Unit 1 was designed the risk of tornadoes was deemed to be vanishingly small and tornadoes were not included in the design basis for the plant. When the question of environmental hazards was revisited for the design basis of Angra Unit 3, tornadoes were included as part of the design basis. Based on this change in philosophy for the Angra site, a review was performed and it was determined that the Raw Water Storage Tank and Reactor Make-up Water Tank, both of which are located outdoors at Angra Unit 1 required protection from tornado driven missiles. The tanks contain water that may be used for emergency cooling, and the water must be available for use during a design basis event. This paper provides an overview of the methodology used to design the tornado missile resistant shield structure for these two tanks.

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