Rough Estimates of Severe Accident Containment Loads Accompanying Vessel Breach in Boiling Water Reactors

1994 ◽  
Vol 108 (3) ◽  
pp. 320-337
Author(s):  
Mark T. Leonard
Keyword(s):  
Boiling Water ◽  
Severe Accident ◽  
Boiling Water Reactors ◽  
Water Reactors

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

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.

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

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.

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.

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