scholarly journals Stress Analysis of HCPB BB under Ex-Vessel LOCA Condition

2021 ◽  
Vol 2108 (1) ◽  
pp. 012088
Author(s):  
Mengdi Dai ◽  
Xiaomo Wang
Keyword(s):  
Stress Distribution ◽  
Stress Field ◽  
Stress Analysis ◽  
Cross Section ◽  
Maximum Stress ◽  
Fusion Reactor ◽  
Vacuum Vessel ◽  
Loss Of Coolant Accident ◽  
Loss Of Coolant ◽  
Size Dimension

Abstract Helium Cooled Pebble Bed Breeding Blanket (HCPB BB) is a kind of concept for the European demonstration fusion reactor (DEMO). The blanket attachment system plays an important role in the mechanical connection of the BB and vacuum vessel. Typically, the mechanical and thermal loads should meet the requirement to avoid collapse of the system with off-normal conditions, e.g., under ex-vessel Loss of Coolant Accident (LOCA. This paper investigates the loading requirement corresponding to the maximum stress that can sustain to avoid the LOCA condition. Firstly, a model of the BB is constructed using SolidWorks. Then, stress analysis is carried out based on the cross section of the blanket. Through simulation, the critical condition for the LOCA case and the maximum stress value for the model are obtained. According to the relevant size dimension from the reference, the blanket’s cross section is drawn, and one can get the stress field under the ex-vessel LOCA through stress analysis. The stress distribution under the ex-vessel LOCA condition is simulated to find out the maximum stress field that the blanket can sustain through this paper. The significance is to predict the possible conditions leading to an accident and find possible methods to avoid them.

Ex-Vessel Loss of Coolant Accident Analysis of ITER Divertor Cooling System Using Modified RELAP/SCADAPSIM/Mod 4.0

2017 ◽  
Vol 3 (4) ◽  
Author(s):  
S. P. Saraswat ◽  
P. Munshi ◽  
A. Khanna ◽  
C. Allison
Keyword(s):  
Heat Flux ◽  
Cooling System ◽  
Heat Removal ◽  
Hydraulic Modeling ◽  
Carbon Fiber Composites ◽  
High Heat Flux ◽  
Vacuum Vessel ◽  
Loss Of Coolant Accident ◽  
Loss Of Coolant ◽  
Accident Scenarios

The initial design of ITER incorporated the use of carbon fiber composites in high heat flux regions and tungsten was used for low heat flux regions. The current design includes tungsten for both these regions. The present work includes thermal hydraulic modeling and analysis of ex-vessel loss of coolant accident (LOCA) for the divertor (DIV) cooling system. The purpose of this study is to show that the new concept of full tungsten divertor is able to withstand in the accident scenarios. The code used in this study is RELAP/SCADAPSIM/MOD 4.0. A parametric study is also carried out with different in-vessel break sizes and ex-vessel break locations. The analysis discusses a number of safety concerns that may result from the accident scenarios. These concerns include vacuum vessel (VV) pressurization, divertor temperature profile, passive decay heat removal capability of structure, and pressurization of tokamak cooling water system. The results show that the pressures and temperatures are kept below design limits prescribed by ITER organization.

Investigation of Air Ingress Into a Vacuum Vessel Related to Particle Re-Suspension and Distribution for Dust Issues in ITER

2017 ◽  
Author(s):  
Emmanuel Porcheron ◽  
Pascal Lemaitre
Keyword(s):  
Large Scale ◽  
Low Pressure ◽  
Normal Operation ◽  
Vacuum Vessel ◽  
Physical Processes ◽  
Time Resolved ◽  
Loss Of Coolant Accident ◽  
Image Velocimetry ◽  
Loss Of Coolant ◽  
Air Ingress

During normal operation of the ITER tokamak, few hundred kilograms of dust containing beryllium (Be) and tungsten (W) will be produced due to the erosion of the walls of the vacuum chamber by the plasma. During a loss of coolant accident (LOCA) or a loss of vacuum accident by air ingress (LOVA), hydrogen could be produced by dust oxidation with steam. Evaluation of the risk of dust and hydrogen explosion, that may lead to a loss of containment, requires studying the physical processes involved in the dust re-suspension and its distribution in the tokamak chamber. This experimental study is conducted by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) to simulate dust re-suspension phenomena induced by high velocity jet under low pressure conditions. Tests are conducted in a large scale facility (TOSQAN, 7 m3) able to reproduce primary vacuum conditions (1 mbar). Optical diagnostics such as PIV technique (Particles Image Velocimetry) are implemented on the facility to provide time resolved measurements of the dust re-suspension in terms of phenomenology and velocity. We present in this paper the TOSQAN facility with its configuration for studying dust re-suspension under low pressure conditions and underway experiments showing the mechanism of dust re-suspension by sonic and supersonic flows.

Analyses for Passive Safety of Fusion Reactor during Ex-Vessel Loss of Coolant Accident

1995 ◽  
Vol 32 (4) ◽  
pp. 265-274 ◽  
Author(s):  
Takuro HONDA ◽  
Takashi OKAZAKI ◽  
Koichi MAKI ◽  
Tatuhiko UDA ◽  
Yasushi SEKI ◽  
...  
Keyword(s):  
Fusion Reactor ◽  
Passive Safety ◽  
Loss Of Coolant Accident ◽  
Loss Of Coolant

Analysis and Comparison of Pad Reinforcement of Pressure Vessel by Elastic and Elastoplastic FEM

2007 ◽  
Author(s):  
Lihua Liang ◽  
Zengliang Gao ◽  
Yangjian Xu ◽  
Kangda Zhang ◽  
Zhaohui Fan
Keyword(s):  
Cylindrical Shell ◽  
Stress Distribution ◽  
Stress Analysis ◽  
Maximum Stress ◽  
Constitutive Relations ◽  
Contact Model ◽  
Integral Model ◽  
The Difference ◽  
Shell Intersections ◽  
Different Diameters

Considering reinforcement pad and the cylindrical shell as an integral model and a contact model, stress analysis for opening-reinforcement structures of a cylindrical shell is performed by elastic and elastoplastic FEM. By comparison of two sub-models and two material constitutive relations (elastic and elastoplastic), the stress distribution of cylindrical shell intersections by the contact model is similar to that by the integral model, but there are some differences of the stress at contact surfaces of the shell and the reinforcement pad between by the contact model and by the integral model. In general, the stress analysis of the integral model for pad reinforcement can approximately represent that of the contact model. Finite element analyses for different nozzle diameters and different oblique angles in nozzle and cylinder shell intersections are carried out. The stress distribution and the maximum stress are affected by oblique angle. But the difference of the maximum stress intensity among different diameters is small.

Analysis for loss of coolant accident in a fusion reactor

1996 ◽  
Vol 31 (3) ◽  
pp. 259-263 ◽  
Author(s):  
T. Hino ◽  
Y. Hirohata ◽  
T. Yamashina
Keyword(s):  
Fusion Reactor ◽  
Loss Of Coolant Accident ◽  
Loss Of Coolant

scholarly journals 3D transient CFD simulation of an in-vessel Loss-Of-Coolant Accident in the EU DEMO fusion reactor

2020 ◽  
Author(s):  
Andrea Zappatore ◽  
Antonio Froio ◽  
Gandolfo Alessandro Spagnuolo ◽  
Roberto Zanino
Keyword(s):  
Cfd Simulation ◽  
Fusion Reactor ◽  
Loss Of Coolant Accident ◽  
Loss Of Coolant ◽  
The Eu

Stresses in Eccentric Stepwise Discontinuous Rings With Transition Section

1968 ◽  
Vol 12 (04) ◽  
pp. 269-278
Author(s):  
Arnold Allentuch ◽  
Joseph Kempner
Keyword(s):  
Stress Distribution ◽  
Cross Section ◽  
Maximum Stress ◽  
Circular Cylindrical Shell ◽  
Radial Line ◽  
Cross Sectional ◽  
Line Load ◽  
Transition Section ◽  
Parameter Values ◽  
Interaction Problem

The stress distribution in a ring of nonuniform cross section under the action of a uniform radial line load is obtained. The solution is an approximation to the exact interaction problem of a reinforced circular cylindrical shell under hydrostatic pressure. The ring is fabricated in three segments; one segment, whose cross-sectional area varies according to a power function, connects two uniform segments. By a proper choice of parameter values the ring geometry can be reduced to two segments, one of uniform depth, the other of continuously varying depth. Several sets of parameters are chosen for numerical calculations. Within these sets only the length of the transition section changes. Thus an appraisal of the importance of the transition section in reducing the maximum stress is made. The stress distribution in a frame with different lengths of transition section is obtained.

Reinforced Elliptical Holes in Stressed Plates

1957 ◽  
Vol 61 (562) ◽  
pp. 688-693 ◽  
Author(s):  
Raymond Hicks
Keyword(s):  
Stress Distribution ◽  
Cross Section ◽  
Maximum Stress ◽  
Elliptical Hole ◽  
Pressure Vessels ◽  
Stress System ◽  
Sectional Area ◽  
Principal Stresses ◽  
Cross Sectional ◽  
Elliptical Holes

SummaryThis paper considers the problem of a reinforced elliptical hole in a plate under the action of a principal stress system of the type found in cylindrical and ellipsoidal pressure vessels. That is, stress systems in which the ratio of the principal stresses is not greater than two to one. It is shown that when the ratio of the major and minor axes of the ellipse can be chosen arbitrarily, practical reinforcements can be designed to give a maximum stress around the hole which is only slightly greater than the maximum stress in a similarly loaded plate with no hole. General expressions are obtained for the stress distribution in the plate around the hole, for the stress acting on a normal cross section of the reinforcement, and for the cross-sectional area of a reinforcement which gives a small stress concentration. These are used to find the variation in the stress distribution around the hole due to reinforcements having different cross-sectional areas when the applied principal stresses are in the ratio of two to one and Poisson's ratio for the material of the plate and reinforcement has practical values.

Identification of Damages and Stress Analysis of Rail/Wheel Rolling Contact Region

2011 ◽  
Vol 462-463 ◽  
pp. 1152-1157 ◽  
Author(s):  
N.A. Akeel ◽  
M.A. Aziman ◽  
Zainuddin Sajuri ◽  
Ahmad Kamal Ariffin ◽  
A.W. Ikhsan
Keyword(s):  
Stress Distribution ◽  
Stress Analysis ◽  
Cross Section ◽  
Contact Area ◽  
Contact Region ◽  
Fem Simulation ◽  
High Hardness ◽  
Rolling Contact ◽  
Wheel Surface ◽  
Wheel Rolling

This paper presents the identification of damages and stress analysis of rail/wheel rolling contact region. The railhead surface of used rail track was investigated to identify damages and the hardness of the rail/wheel contact area was measured. Finite element method FEM code, ANSYS was used to determine the stress distribution at vicinity of rail/wheel contact area. The results showed that the hardness increased on the contact area between rail and wheel due to repeated rolling contact of rail and wheel surface. Severe damages and cracks were observed on the railhead surface and in the cross section of the rail at the contact region. The FEM simulation showed that the highest stress distribution regions were matched with the area of severely damage and high hardness obtained from the observation and experimental results.

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