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Showing 1 to 19 of 19 for “"Loss of Coolant Accident (LOCA)"”.
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Heat and Mass Transfer in Reactor Core During a Loca-Single Channel Analysis (Mixed Convection, Numerical, Flow, Thermal-Hydraulics)
Ability to predict the scenario following a loss-of-coolant accident (LOCA) is of central importance in the safety analysis of water reactors. During LOCA, the reactor core is uncovered and the residual water inventory is boiled off by fission products decay heating. For the Three Mile Island …
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A Study on the Mechanical Characteristics of a Fiberglass Bed Formed During a Loss-of-Coolant-Accident at a PWR Nuclear Facility
Following a Loss-of-Coolant-Accident (LOCA) in one of the primary coolant lines in the containment building of a PWR Facility, it is possible that fiberglass pipe insulation could be dislodged and washed down to the sump pool. This fiberglass could collect into a bed' and cause blockage on the sump …
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Design of an experimental loop for post-LOCA heat transfer regimes in a Gas-cooled Fast Reactor
The goal of this thesis is to design an experimental thermal-hydraulic loop capable of generating accurate, reliable data in various convection heat transfer regimes for use in the formulation of a comprehensive convection heat transfer correlation. The initial focus of the design is to ensure that …
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CFD Analyses of Flow Structures in Air-Ingress and Rod Bundle Problems
… One study is the air-ingress phenomenon during a loss of coolant accident (LOCA) scenario, and the other is a 5-by-5 bundle assembly problem under a design of PWRs. The objectives are to investigate the Kelvin-Helmholtz instability of the gravity-driven stratified flows inside a coaxial pipe and …
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An alternate high pressure injection system for pressurized-water reactors
… Injection System (ICIS) performance during a loss-of-coolant accident (LOCA) due to a major rupture in the primary system of a pressurized water reactor (PWR), tests were conducted using the thermal-hydraulic computer code RELAP4/MOD5.</p> <p>The results for the overall plant system show that …
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Flooding and non-equilibrium in counter-current flows with reference to pressurised water reactors
During the refill stage of a Loss of Coolant Accident (LOCA) in Pressurised Water Reactor (PWR) the effectiveness with which the emergency coolant penetrates to the lower plenum, and hence to the core, is of paramount importance. This thesis presents the results of experimental and theoretical work …
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Fuel performance of multi-layered zirconium and silicon carbide based Accident Tolerant Fuel claddings
The Accident Tolerant Fuel (ATF) program is focused on extending the time for fuel failure during postulated severe accidents compared to the standard UO₂-Zr alloy fuel system. This thesis investigates the feasibility of four different cladding concepts, two of which are zirconium-alloy based and …
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TRACE code validation of boiling water reactor spray cooling injection into a SVEA fuel assembly
… license nuclear power plants to a greater degree of accuracy and safety assurance. Such codes necessitate efforts to qualify their validity, particularly with modeling the complex thermal-hydraulics phenomena associated with Loss-of-Coolant Accident (LOCA) scenarios. Emergency spray cooling …
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Investigation of calcium orthophosphate chemical effects in a post-LOCA nuclear reactor containment
… from NUKON fiberglass in containment following a Loss of Coolant Accident (LOCA) could lead to the formation of chemical precipitates that in turn cause head-loss increase due to filtering through a fibrous debris accumulation at the sump pump screens. Experiments conducted on the bench scale show …
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EXPERIMENTAL STUDIES OF THE CHEMICAL EFFECTS OF ZINC-BEARING MATERIALS FOLLOWING A LOSS-OF-COOLANT ACCIDENT IN A PRESSURIZED WATER REACTOR
… Commission (U.S. NRC) to assess the effect of debris loading on pressurized water reactor (PWR) emergency core cooling systems (ECCS) sump strainers during a Loss-of-Coolant Accident (LOCA). Potential contributors to the debris loading include latent dirt, fiberglass insulation, paints, …
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Inverse uncertainty quantification of input model parameters for thermal-hydraulics simulations using expectation-maximization under non-Bayesian and Bayesian framework
Uncertainty quantification of computer simulation response requires knowledge of input model parameter uncertainty. However, like most system codes, nuclear thermal-hydraulics code TRACE does not provide any information on statistical properties of input model parameters. Moreover, the input model …
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Advanced thermal hydraulic simulations for human reliability assessment of nuclear power plants
… the last two decades. However, there is a lack of understanding of the magnitude of the effect of thermal hydraulic (TH) uncertainties upon the failure probabilities of the operator actions of nuclear units. I demonstrate in this work that there is an effect of TH uncertainties on the operating …
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Estimation of coping time in pressurized water reactors for accident tolerant fuel claddings
The Fukushima Nuclear Power Plant (NPP) accident in Japan has motivated improving the safety of current light water reactors (LWRs). Accident tolerant fuels (ATF) are being developed to enhance the safety of LWRs by tolerating loss of active cooling in the core for a longer duration compared to …
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Silicon carbide oxidation in high temperature steam
… reaction which can potentially occur during a loss of coolant accident (LOCA), and may become autocatalytic beyond 1,200 0C, thus generating a large amount of hydrogen. The concern for the zircaloy oxidation reaction has been heightened since the March 2011 events of Fukushima, Japan. One …
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Evaluation of multilayer silicon carbide composite cladding under loss of coolant accident conditions
… and a 1000°C higher melting temperature, all of which are important during a loss of coolant accident (LOCA). To improve the performance of SiC cladding, a multilayered architecture consisting of layers of monolithic SiC (mSiC) and SiC/SiC ceramic matrix composite (CMC) has been proposed. In …
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Design optimization of advanced PWR SiC/SiC fuel cladding for enhanced tolerance of loss of coolant conditions
… In this work the mechanical performance of three unique architectures of three-layer silicon carbide (SiC) composite cladding is experimentally investigated under conditions associated with the loss of coolant accident (LOCA), and analytically under various conditions. Specifically, this …
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High temperature steam oxidation of titanium-coated Zircaloy-2 and Titanium-Zirconium Alloys
… Daiichi Nuclear Disaster changed the course of nuclear power production worldwide. Though most people have focused on the negatives of the events, there have been major advantageous outcomes. An industry, which general consensus would say is extremely safe, has become even safer based on the …
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Analysis of reverse flow restriction device to prevent fuel dryout during loss of coolant and instability accidents of boiling water reactors
… introduces a new method to increase the safety of Boiling Water Reactors (BWRs) during the BWR instability and Loss of Coolant Accidents (LOCA). The method is based on a device called Reverse Flow Restriction Device (RFRD) and its purpose is to allow the flow in the forward direction, but …
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Analysis of Reverse Flow Restriction Device to Prevent Fuel Dryout During Loss of Coolant and Instability Accidents of Boiling Water Reactors
… in DSpace on 2017-07-06T18:55:56Z (GMT). No. of bitstreams: 3 Radaideh_Majdi_I_MS.pdf: 3702916 bytes, checksum: d9ab8cfcddc4314d381232b2ad3af591 (MD5) Radaideh_Majdi_I_MS_ABS.pdf: 113055 bytes, checksum: 6dd5088a2264a7ad7262bf468569a820 (MD5) license.txt: 4813 bytes, checksum: …