New finite element-based modeling of reactor core support plate failure

Kerntechnik ◽  
2017 ◽  
Vol 82 (6) ◽  
pp. 685-692
Author(s):  
T. Hajas ◽  
P. Pandazis ◽  
L. Lovász ◽  
B. Babcsán
Keyword(s):  
Finite Element ◽  
Reactor Core ◽  
Support Plate ◽  
Plate Failure

Transient Simulation on Reactor Core Melt and Lower Support Plate Ablation in In-Vessel Retention

2017 ◽  
Author(s):  
Xuyi Chen ◽  
Xiaoying Zhang ◽  
Junying Xu ◽  
Biao Wang ◽  
Dekui Zhan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Moving Boundary ◽  
Radiation Heat Transfer ◽  
Reactor Core ◽  
Saturated Steam ◽  
Temperature History ◽  
Core Mass ◽  
3 Dimensional ◽  
Support Plate ◽  
Impingement Heat Transfer

To precisely understand the accident process of reactor core melt in In-vessel retention (IVR) condition, 3-dimensional transient thermal conduction analysis with moving boundary is performed on quarter reactor core model. The decline of decay power and water level in reactor pressure vessel (RPV), and the radial distribution of assemblies of different material is considered. Convective heat transfer on rod surface and coolant interface is computed with empirical correlation of natural convection of saturated steam vapor / water. Radiation heat transfer with 16 neighboring rod is considered. Also, a dynamic ablation model is developed to simulate the ablation of lower support plate (LSP) caused by continuously accumulation of molten corium. The impingement heat transfer of the falling corium and the molten pool formed in LSP ablation cavity is taken into account. The simulation gives the ablation process on the surface of LSP as well as temperature history and molten proportion of the reactor core, which shows agreement with reference. Simulation shows: the melt process of reactor core accelerated in the accident process of 2600s, when coolant in RPV dry up. 65% of the core mass has molten at 8000 second. LSP is completely penetrated in 6000s, the ablation of LSP is mainly focused on an annular region of radius 700mm.

Numerical Analysis of Compound ECT Signals due to Various Tube Defects near Support Plate in Steam Generator

2006 ◽  
Vol 110 ◽  
pp. 177-182
Author(s):  
Young Kil Shin ◽  
Yun Tai Lee ◽  
Myung Ho Song
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Steam Generator ◽  
Eddy Current ◽  
Slope Angle ◽  
Signal Prediction ◽  
Support Plate ◽  
Combined Use ◽  
Compound Signal ◽  
Effect Of Support

In this paper, eddy current signals from various anomalous defects in the steam generator tube are numerically predicted and their signal slope characteristics are investigated. The signal variations due to increased frequencies are also observed. Based on the accumulated knowledge, the analysis of compound signal is attempted which includes the effect of support plate. Both differential and absolute bobbin probe signals are analyzed. For the signal prediction, axisymmetric finite element modeling is used and this leads us to the utilization of slope angle analysis of the signal. Results show that differential signals are useful for locating the position of defect under the support plate, while absolute signals are easy to presume and interpret even though the effect of support plate is mixed. Combined use of these two types of signals will help us accomplish a more reliable inspection.

Seismic Analysis and Redesign of the Center Row in Reactor Core

2014 ◽  
Vol 668-669 ◽  
pp. 244-247
Author(s):  
Mei Huang ◽  
Yuan Yuan Zhao ◽  
Zhao Yang Xing ◽  
Hao Yuan ◽  
Jian Nan Tang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Impact Force ◽  
Seismic Analysis ◽  
Reactor Core ◽  
Maximum Force ◽  
Seismic Load ◽  
Element Method

In this article, finite element method is used to analyze the properties of the reactor core under seismic load, and redesign the center assemblies to resist deformation and impact force. The result shows that the maximum force on the lug boss is decreased while the springs are applied.

A Method for Online Calibration of MAAP Simulations in a Severe Accident Management System Database

2017 ◽  
Author(s):  
Weifeng Xu ◽  
Fangqing Yang ◽  
Peng Chen ◽  
Yehong Liao
Keyword(s):  
Management System ◽  
Reactor Vessel ◽  
Severe Accident ◽  
Outlet Temperature ◽  
Online Calibration ◽  
Support Plate ◽  
Initial Event ◽  
Accident Management ◽  
Accident Simulation ◽  
Plate Failure

During a nuclear plant accident, five accident events are usually considered, including core uncovery, core outlet temperature arrived at 650 °C, core support plate failure, reactor vessel failure and containment failure. In accident emergency aspect, when an accident happens, the initial event can be utilized in the severe accident management system which is based on MAAP to simulate the long process of the accident, so as to provide support for operators to take actions. However, in MAAP, many sensitivity parameters exist, which reflect phenomenological uncertainty or models uncertainty and will influence the happening time of the five accident events above. In this paper, based on MAAP5 and LOCAs, the CPR1000 is simulated to analyze the influences of MAAP5’s sensitivity parameters reflecting phenomenological uncertainty on the accident process, which is aimed to find out the sensitivity parameters associated to the five important accident events and build the database between these sensitivity parameters and five accident events’ happening time. Then, based on the research above, a preliminary approach to optimize the MAAP5’s accidents simulation is introduced, which is realized by adjusting sensitivity parameters. Finally, the application of this research will be showed in a severe accident management system developed by us. The research results offer great reference significance for the severe accident simulation and prediction in MAAP5.

Coupled Neutronics-mechanics Analysis Method for Evaluation of Reactivity Change Due to Core Distortion in Sodium Fast Reactor

2021 ◽  
Author(s):  
Janos Bodi ◽  
Alexander Ponomarev ◽  
Konstantin Mikityuk
Keyword(s):  
Finite Element ◽  
Fast Reactor ◽  
Computer Aided Design ◽  
Reactor Core ◽  
Mechanical Analysis ◽  
Analysis Method ◽  
Reactivity Effect ◽  
Reactor Types ◽  
Verification Process ◽  
Set Up

Abstract In this paper, a reactor core mechanical analysis method is introduced to provide a tool to calculate the reactivity effect of the fuel subassembly displacement in the reactor core which is an important problem for reactor types such as the Sodium-cooled Fast Reactor (SFR). The presented method relies on the following two main steps: 1) Core deformation calculation through a Computer-Aided Design (CAD) based finite element solver and 2) Static neutronic simulation on the original undeformed and deformed core models with a Mode Carlo code to quantify the reactivity effect. The technique makes it possible to accurately simulate the deformed geometry of the reactor core and to use this deformed shape model directly in the neutronic analysis. The paper includes the verification process which was conducted to compare the accuracy of the finite element solver to the theoretical solutions regarding the deformation of a hexagonal subassembly. Moreover, the neutronic calculation accuracy has been demonstrated. Following this, a validation work has been performed on the Phenix Sodium-cooled Fast Reactor based on the data obtained from previous, end-of-life test, experimental set-up. This procedure proved the accuracy of the presented methodology for both the verification and the validation cases, giving the capability to assess the reactivity effect of a non-uniform core deformation in an SFR.

scholarly journals Study on Fatigue Crack of Supporting Plate on Sonic Vibration Head

2014 ◽  
Vol 6 ◽  
pp. 106238
Author(s):  
Wang Yu ◽  
Lei Yuru ◽  
Liu Bao-lin ◽  
Li Zhi-jun
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fatigue Crack ◽  
Stress Concentration ◽  
Fatigue Failure ◽  
Fatigue Testing ◽  
Steel Structures ◽  
Support Plate ◽  
Fatigue And Fracture ◽  
Supporting Plate

The supporting plate is one of the key parts of the sonic vibration head, and the regular fatigue and fracture make the support plate be one of the most venerably damaged units, resulting in huge loss in economy and security. After analyzing the loading states of the supporting plate on sonic vibration head, the mechanical stresses of three kinds of supporting plate under different operation load cases are simulated by the method of finite element method (FEM). The effects of stress of supporting plate are studied by means of fatigue testing on actual drilling processing. The results show that the steel structures fatigue failure is caused by stress concentration and unbalance. The optimal supporting plate structure is selected by the simulation and test.

A Comparative Study on Elastic Behavior of Trefoil Patterned Perforated Plate

2010 ◽  
Author(s):  
Min-Ki Cho ◽  
Chang-Hoon Ha ◽  
Moo-Yong Kim ◽  
Sang-Cheol Lee ◽  
Jea-Mean Koo ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Elastic Modulus ◽  
Elastic Properties ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Element Analysis ◽  
Bending Tests ◽  
Support Plate ◽  
The Finite Element Analysis

A tube support plate is one of the significant parts of a steam generator, which confines the rotational and translational motion of tubes caused by the hydraulic and seismic load. It also provides a flow path along the tubes. There are various types of tube support plates according to the component designer’s preference. In this investigation, ten types of trefoil Broached Tube Support Plate (BTSP) specimens made from ASME stainless steel were analyzed and tested to determine the appropriate shape of trefoil BTSP in the view of the elastic properties including elastic modulus and Poisson’s ratio. The types of trefoil BTSP specimens were designated as SI through S5 and L1 through L5 for S and L types, respectively. These specimens are categorized by the shape and dimension of broached hole. Ten specimens were investigated through finite element analysis, and compression and bending tests. The dimensions of the test specimens were decided through a previous research study done to examine appropriate shape for the compression and bending tests. The equivalent elastic properties of BTSP were obtained by the finite element analysis as per different loading orientation as well as the various specimen types. Autodesk® Inventor™ software was used to make the analytical model and ABAQUS® software was used for the analysis and post-processing. The equivalent elastic properties of BTSP specimens were also acquired by the compression and bending tests. From the results of the finite element analysis, and the compression and bending tests, the appropriate shapes of trefoil BTSP with regard to the equivalent elastic modulus, and Poisson’s ratio are suggested as L4, S3, and S4.

Strength Prediction of Bonded T-Peel Joint with Single Overlap Support

2011 ◽  
Vol 236-238 ◽  
pp. 781-788
Author(s):  
Ali M. Al Samhan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Joint Strength ◽  
Tensile Loading ◽  
Strength Prediction ◽  
Support Plate ◽  
Plate Length ◽  
Bonded Joint ◽  
Element Method

Bonded structure are commonly three types, purely adhesive bonded, weld-bonded and adhesive/mechanical structures. Generally, peel and overlapped joints are commonly used in the development of bonded structures. T-Peel bonded joint has week tensile loading strength compare to double-overlap bonded joint. The present work aimed to predicting the strength of bonded T-peel joint with single overlap support using finite-element method. For comparison purposes, normal bonded T-peel joint is included in this study. It was found the introduction of a single overlap support for bonded T-peel joint strengthening the joint by 300%. Furthermore, it was reported that the proposed joint strength increased further with increase of the overlap support plate length and thickness.

Prediction and Analysis of ECT Signals due to Tube Defects near Support Plate in Steam Generator

2006 ◽  
Vol 321-323 ◽  
pp. 420-425
Author(s):  
Young Kil Shin ◽  
Sung Chul Song ◽  
Hee Sung Jung ◽  
Yun Tai Lee
Keyword(s):  
Finite Element ◽  
Steam Generator ◽  
Slope Angle ◽  
Defect Characterization ◽  
Frequency Increase ◽  
Signal Prediction ◽  
Support Plate ◽  
Signal Characteristics ◽  
Effect Of Support ◽  
Signal Understanding

In this paper, absolute and differential eddy current signals from various shapes and sizes of defects in the steam generator tube are numerically predicted and their slope characteristics are investigated. The signal variations due to frequency increase are also observed. Then, the analysis of mixed defect signals affected by a ferromagnetic support plate is attempted. Axisymmetric finite element modeling is used for signal prediction and the slope angle of signal is used importantly in analyzing the signal. Results show that differential signals are useful for locating the position of a defect inside the support plate hole, while absolute signals are easy to presume and interpret even though the effect of support plate is mixed in the signal. Understanding of respective signal characteristics and relationship between them will be helpful for more reliable defect characterization.

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