Evaluation of the Structural Integrity of the Jet Pumps of a Boiling Water Reactor under Hydrodynamic Loading

Cuahquentzi, Noel M.; Gómez, Luís Héctor Hernández; López, Pablo Ruiz; Urriolagoitia-Calderón, Guillermo; Beltrán-Fernández, Juan Alfonso; Urriolagoitia-Sosa, Guillermo; Cuamatzi, Enrique F.; Ramírez, Alejandro; Ángeles, Beatriz Romero

doi:10.4028/www.scientific.net/ddf.348.261

Cited by 6 publications

(4 citation statements)

References 2 publications

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“…Code and some other procedures [1,5,7,15,16] proposed for the evaluation of the structural integrity of the piping system can be followed. Therefore, a criterion to prevent potential failures of the steam dryer can be established.…”

Section: Discussionmentioning

confidence: 99%

Simulation of the Acoustic Loads Generated in the Intersection of a Main Steam Line and its Safety Relief Valve Branch of a BWR Plant under Extended Power Uprate Condition

Ocampo-Ramírez

Hernández-Gómez

Ruiz-López³

et al. 2015

DDF

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The structural integrity of a BWR nuclear power plant can be compromised due to severe dynamic loads. Acoustic loads coming from a Safety Relief Valve branch can be adversely amplified if the steam flow is increased at the Main Steam Piping. This phenomenon has been reported previously in one BWR nuclear power plant. Its steam dryer was fractured and loose parts were generated due to high-cycle fatigue. This event has driven the United States Nuclear Regulatory Commission to issue specific regulations to evaluate acoustic loads which would be detrimental to the BWR steam dryer. In this paper, the acoustic loads were simulated when the steam flow is incremented from normal operation conditions to an Extended Power Uprate condition. It was analyzed, when the output power was incremented 14% and 28%. The initial conditions were determined with Computational Fluid Dynamics under steady state condition. This data was used in subsequent transient analysis. The model of Large Eddy Simulation was used and the acoustic simulation was performed with the Fowcs Williams and Hawkings Method. The Power Spectral Density was obtained with Fast Fourier Transform. The frequency peaks were found between 148 Hz and 155 Hz. These results are consistent with those obtained with the Helmholtz model and other results reported in the open literature. The results show that the peak pressure can be increased up to six times in resonance conditions, corresponding to a power uprate of 28%.

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Section: Discussionmentioning

confidence: 99%

Simulation of the Acoustic Loads Generated in the Intersection of a Main Steam Line and its Safety Relief Valve Branch of a BWR Plant under Extended Power Uprate Condition

Ocampo-Ramírez

Hernández-Gómez

Ruiz-López³

et al. 2015

DDF

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“…Natural Frequencies (Hz) Stevens and coworkers [15] Cuahquentzi and coworkers [16] This It was observed that the fourth mode shape is torsional (Figure 6). Its natural frequency is 41.82 Hz.…”

Section: Mode Shapementioning

confidence: 97%

“…Cuahquentzi and coworkers [16] determined the first 10 mode shapes and their natural frequencies with ANSYS code and SAP 2000 code. They considered the hydraulic loads inside the jet pump.…”

Section: Natural Frequencies Of the Jet Pump Assembly Submerged In Watermentioning

confidence: 99%

Analysis of the Leakage-Flow-Induced Vibration of a Slip Joint in a Jet Pump of a Boiling Water Reactor

Cruz-Castro

Palafox

Sánchez

et al. 2019

DDF

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The purpose of this analysis is to evaluate the structural integrity of the jet pump assembly of a BWR during the performance of its operational and safety functions. The natural frequencies and vibration modes of the jet pump assembly immersed in water were determined. It was observed that the fourth mode shape was torsional, and its associated resonance frequency was 41.82 Hz. Also, the vibration induced by the flow in the leakage of the slip joint was analyzed with an axisymmetric model. The gap of the slip joint was varied from 0.2 mm until 0.65bmm. A gap between 0.6 and 0.64, would cause flow-induced vibration because this excitation frequency matches with the fourth natural frequency of the jet pump assembly. The above was carried out using computational fluid dynamics, as well as the finite element method, with ANSYS Structural and ANSYS Fluent codes.

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“…e natural frequencies were evaluated with different gaps at the slip joint. Cuahquentzi et al [16] determined the natural frequencies and the modes of vibration of the jet pumps with a 3D model. Cuamatzi-Meléndez and Flores-Cuamatzi [17] analyzed the response of the natural frequencies versus the displacement, velocity, and acceleration of the structure.…”

Section: Natural Frequencies Of the Jet Pump Assembly Submerged In Watermentioning

confidence: 99%

Cross Flow Analysis over the Jet Pumps of a BWR-5 Reactor

Soto-Mendoza

Armenta-Molina

Pérez-Montejo

et al. 2021

Science and Technology of Nuclear Installations

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The recirculation system of a BWR-5 has 20 jet pumps. They are submerged in water in the cylindrical annular zone of the reactor. Their main function is the development of a forcing flow through the nuclear core. It increases the power of the reactor compared with the one obtained by natural circulation. These components have an important safety function in the operation of the reactor. In accordance with document BWRVIP-41 R4, it was concluded that the vibration induced by cross flow over the jet pump assemblies is one of the degradation mechanisms of such pumps. In this paper, the vibration induced by the cross flow at a jet pump assembly BWR-5 was analyzed. A numerical approach was developed. The natural frequencies were obtained, considering the Fluid-Structure Interaction (FSI). The first natural frequency was 25.7 Hz. A Computational Fluid Dynamics (CFD) analysis was carried, in conjunction with the Power Spectral Density (PSD). A frequency of vortex generation of 0.48 Hz was obtained. A vortex generation analysis was carried out with the Q-criteria. The results showed that resonance conditions are unlikely. Therefore, the structural integrity of the jet pump assemblies is maintained.

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Evaluation of the Structural Integrity of the Jet Pumps of a Boiling Water Reactor under Hydrodynamic Loading

Cited by 6 publications

References 2 publications

Simulation of the Acoustic Loads Generated in the Intersection of a Main Steam Line and its Safety Relief Valve Branch of a BWR Plant under Extended Power Uprate Condition

Simulation of the Acoustic Loads Generated in the Intersection of a Main Steam Line and its Safety Relief Valve Branch of a BWR Plant under Extended Power Uprate Condition

Analysis of the Leakage-Flow-Induced Vibration of a Slip Joint in a Jet Pump of a Boiling Water Reactor

Cross Flow Analysis over the Jet Pumps of a BWR-5 Reactor

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