Behavior of Simulated Molten Metal at Channel Modeled Boiling Water Reactors

2017 ◽  
Author(s):  
Yutaro Hihara ◽  
Kota Matsuura ◽  
Hideaki Monji ◽  
Yutaka Abe ◽  
Akiko Kaneko ◽  
...  
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Numerical Analysis ◽  
Molten Metal ◽  
Numerical Results ◽  
Boiling Water ◽  
Severe Accident ◽  
Boiling Water Reactors ◽  
Simulation Code ◽  
Water Reactors

When a severe accident occurs, decommissioning work becomes important task. In the decommissioning work after the severe accident, establishing the way to estimate the sedimentation place of molten debris is important. However, the technique to estimate exactly sedimentation place has not been enough. Therefore, the detailed and phenomenological numerical simulation code named JUPITER for predicting the molten core behavior is under development. The comparison between experimental and numerical results is necessary to clarify the validity of the numerical analysis code. This study provides the experimental data for a BWR to examine the numerical simulation code in order to contribute to progress of the decommissioning work.

Evaluation of a Severe Accident Management Strategy for Boiling Water Reactors—Drywell Flooding

1994 ◽  
Vol 106 (2) ◽  
pp. 139-154 ◽  
Author(s):  
Donghan Yu ◽  
Leiming Xing ◽  
William E. Kastenberg ◽  
David Okrent
Keyword(s):  
Management Strategy ◽  
Boiling Water ◽  
Severe Accident ◽  
Boiling Water Reactors ◽  
Accident Management ◽  
Water Reactors

Features of a control blade degradation observed in situ during severe accident conditions in boiling water reactors

2019 ◽  
Vol 56 (5) ◽  
pp. 440-453 ◽  
Author(s):  
Anton Pshenichnikov ◽  
Saishun Yamazaki ◽  
David Bottomley ◽  
Yuji Nagae ◽  
Masaki Kurata
Keyword(s):  
Boiling Water ◽  
Severe Accident ◽  
Boiling Water Reactors ◽  
Water Reactors ◽  
Accident Conditions

Numerical Analysis of the Flow Within a Clark Turbocharger Compressor

2004 ◽  
Author(s):  
K. S. Chapman ◽  
Sudip Dey ◽  
Ali Keshavarz
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Numerical Analysis ◽  
Flow Field ◽  
Field Test ◽  
Numerical Results ◽  
Operating Conditions ◽  
Flow Recirculation ◽  
Flow Through

The flow field within a Clark turbocharger compressor has been thoroughly analyzed by numerical simulation. The numerical simulation was validated with experimental data collected from field test sites. The numerical results are found to closely match the experimental data. Once validated, the numerical simulation was used to investigate the flow field within the turbocharger compressor under a variety of operating conditions. Several regions of flow recirculation were identified that restrict flow through the turbocharger.

Simulation for Startup Transients in a Natural Circulation Boiling Loop

2008 ◽  
Author(s):  
S. P. Lakshmanan ◽  
P. Pradeep Kumar ◽  
Manmohan Pandey ◽  
Kannan N. Iyer
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Numerical Simulations ◽  
Natural Circulation ◽  
Boiling Water ◽  
Boiling Water Reactors ◽  
Test Facility ◽  
Current Interest ◽  
Water Reactors ◽  
Experimental Findings

Startup of natural circulation boiling water reactors is of current interest due to the transients that occur at low pressure and low power conditions. Numerical simulation can be a useful tool for studying startup transients and for devising appropriate startup procedure. In the present work, a numerical model of an experimental test facility has been developed with RELAP5/MOD3.4. This model has been used to devise a startup procedure, which has been successfully implemented in the test facility. Numerical simulations for the startup transients have been done with the RELAP5 model and results have been compared with experimental findings. The nature of oscillations predicted by numerical simulations is similar to that observed in the experiment. This study demonstrated one possible method for developing startup procedures for natural circulation boiling water reactors.

Recirculation Pump Speed Control System Upgrades in Nuclear Boiling Water Reactors

2008 ◽  
Author(s):  
James W. Morgan
Keyword(s):  
Control System ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Flow Control ◽  
Nuclear Power ◽  
Boiling Water ◽  
Boiling Water Reactors ◽  
Pump Speed ◽  
Water Reactors ◽  
Generator Sets

The nuclear power industry is faced with determining what to do with equipment and instrumentation reaching obsolescence and selecting the appropriate approach for upgrading the affected equipment. One of the systems in a nuclear power plant that has been a source of poor reliability in terms of replacement parts and control performance is the reactor recirculation pump speed/ flow control system for boiling water reactors (BWR). All of the operating BWR-3 and BWR-4’s use motor-generator sets, with a fluid coupled speed changer, to control the speed of the recirculation water pumps over the entire speed range of the pumps. These systems historically have had high maintenance costs, relative low efficiency, and relatively inaccurate speed control creating unwanted unit de-rates. BWR-5 and BWR-6 recirculation flow control schemes, which use flow control valves in conjunction with two-speed pumps, are also subject to upgrades for improved performance and reliability. These systems can be improved by installing solid-state adjustable speed drives (ASD), also known as variable frequency drives (VFD), in place of the motor-generator sets and the flow control valves. Several system configurations and ASD designs have been considered for optimal reliability and return on investment. This paper will discuss a highly reliable system and ASD design that is being developed for nuclear power plant reactor recirculation water pump controls. Design considerations discussed include ASD topology, controls architecture, accident, transient and hydraulic analyses, potential reactor internals modifications, installation, demolition and economic benefits.

Simulation of a Free Standing Riser Model and Validation With Experimental Results

2014 ◽  
Author(s):  
Marcio Yamamoto ◽  
Sotaro Masanobu ◽  
Satoru Takano ◽  
Shigeo Kanada ◽  
Tomo Fujiwara ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Previous Experiment ◽  
Numerical Results ◽  
Experimental Results ◽  
Previous Article ◽  
Scale Model ◽  
Analysis Software ◽  
Free Standing ◽  
Reduced Scale

In this article, we present the numerical analysis of a Free Standing Riser. The numerical simulation was carried out using a commercial riser analysis software suit. The numerical model’s dimensions were the same of a 1/70 reduced scale model deployed in a previous experiment. The numerical results were compared with experimental results presented in a previous article [1]. Discussion about the model and limitations of the numerical analysis is included.

Vibro-Stone Column Reinforcement Mechanism and Numerical Analysis

2012 ◽  
Vol 446-449 ◽  
pp. 1940-1943
Author(s):  
Yang Liu ◽  
Hong Xiang Yan
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Pore Pressure ◽  
Numerical Procedure ◽  
Numerical Results ◽  
Excess Pore Pressure ◽  
Stone Column ◽  
Reinforcement Mechanism ◽  
Consolidation Theory ◽  
Excess Pore

Numerical simulation of vibro-stone column is taken to simulate the installation of vibro-stone column. A relationship based on test is adopted to calculate the excess pore pressure induced by vibratory energy during the installation of vibro-stone column. A numerical procedure is developed based on the formula and Terzaghi-Renduric consolidation theory. Finally numerical results of composite stone column are compared single stone column.

The Steam Turbine Retrofitting of Six Boiling Water Reactor Units Using Innovative Engineering and Laser Scanning Techniques

2009 ◽  
Author(s):  
Mike Jones ◽  
David J. Nelmes
Keyword(s):  
Steam Turbine ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Boiling Water ◽  
Boiling Water Reactors ◽  
Extensive Experience ◽  
Turbine Generators ◽  
The Usa ◽  
Water Reactors ◽  
Scan Data

Alstom Power is executing the steam turbine retrofit of six nuclear units for Exelon Generation in the USA. The existing turbine-generators are an 1800 RPM General Electric design originally rated at 912 MWe and 1098 MWe and powered by Boiling Water Reactors. 18 Low Pressure inner modules will be replaced, with the first due to be installed in March 2010. This project is particularly challenging — the aggressive retrofit installation schedule is compounded by the requirement to handle radioactively contaminated equipment and also comply with demanding regulations applicable to BWR plant. The author’s company has extensive experience in the steam turbine retrofit business, having supplied around 800 retrofit cylinders globally since the 1970’s. However, this LP upgrade challenges the established techniques used in the business and requires extraordinary effort. Traditional retrofit engineering and installation principles have been interrogated and developed to meet the specific requirements of this project. Innovative techniques are introduced, including the extensive use of the Leica HDS 6000 laser scanner to model the existing plant. The approach has advanced the field of steam turbine retrofit design and installation significantly. The first section of this paper focuses on the extraordinary considerations of the project and the challenges surrounding BWR plant. The second part describes the laser scanning technique and the application of scan data. It outlines the innovative solutions which have been developed.

On Numerical Simulation of the Stepped Soil-Nail Wall

2013 ◽  
Vol 353-356 ◽  
pp. 692-695
Author(s):  
Chang Zhi Zhu ◽  
Quan Chen Gao
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Internal Force ◽  
Numerical Results ◽  
Analysis Model ◽  
Foundation Pit ◽  
Soil Nails ◽  
Soil Nail ◽  
Soil Nail Wall ◽  
Design And Construction

Based on an Engineering Example which was supported by the stepped soil-nail wall, a numerical analysis model was established by FLAC3D,and the process of the excavation and supporting was simulated, and the numerical results of the soil nails internal force and foundation pit deformation were obtained. The simulated result was consistent with the measured results. It shows that the method of FLAC3D numerical analysis can be used to the numerical analysis of foundation pit excavation and supporting, and it will provide the basis for the design and construction of practice project.

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