Simulating High Flux Isotope Reactor Core Thermal-hydraulics Via Interdimensional Model Coupling

Simulating High Flux Isotope Reactor Core Thermal-hydraulics Via Interdimensional Model Coupling PDF Author: Adam Ross Travis
Publisher:
ISBN:
Category :
Languages : en
Pages : 131

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Book Description
A coupled interdimensional model is presented for the simulation of the thermal-hydraulic characteristics of the High Flux Isotope Reactor core at Oak Ridge National Laboratory. The model consists of two domains—a solid involute fuel plate and the surrounding liquid coolant channel. The fuel plate is modeled explicitly in three-dimensions. The coolant channel is approximated as a two-dimensional slice oriented perpendicular to the fuel plate’s surface. The two dimensionally-inconsistent domains are linked to one another via interdimensional model coupling mechanisms. The coupled model is presented as a simplified alternative to a fully explicit, fully three-dimensional model. Involute geometries were constructed in SolidWorks. Derivations of the involute construction equations are presented. Geometries were then imported into COMSOL Multiphysics for simulation and modeling. Both models are described in detail so as to highlight their respective attributes—in the 3D model, the pursuit of an accurate, reliable, and complete solution; in the coupled model, the intent to simplify the modeling domain as much as possible without affecting significant alterations to the solution. The coupled model was created with the goal of permitting larger portions of the reactor core to be modeled at once without a significant sacrifice to solution integrity. As such, particular care is given to validating incorporated model simplifications. To the greatest extent possible, the decrease in solution time as well as computational cost are quantified versus the effects such gains have on the solution quality. A variant of the coupled model which sufficiently balances these three solution characteristics is presented alongside the more comprehensive 3D model for comparison and validation.

Simulating High Flux Isotope Reactor Core Thermal-hydraulics Via Interdimensional Model Coupling

Simulating High Flux Isotope Reactor Core Thermal-hydraulics Via Interdimensional Model Coupling PDF Author: Adam Ross Travis
Publisher:
ISBN:
Category :
Languages : en
Pages : 131

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Book Description
A coupled interdimensional model is presented for the simulation of the thermal-hydraulic characteristics of the High Flux Isotope Reactor core at Oak Ridge National Laboratory. The model consists of two domains—a solid involute fuel plate and the surrounding liquid coolant channel. The fuel plate is modeled explicitly in three-dimensions. The coolant channel is approximated as a two-dimensional slice oriented perpendicular to the fuel plate’s surface. The two dimensionally-inconsistent domains are linked to one another via interdimensional model coupling mechanisms. The coupled model is presented as a simplified alternative to a fully explicit, fully three-dimensional model. Involute geometries were constructed in SolidWorks. Derivations of the involute construction equations are presented. Geometries were then imported into COMSOL Multiphysics for simulation and modeling. Both models are described in detail so as to highlight their respective attributes—in the 3D model, the pursuit of an accurate, reliable, and complete solution; in the coupled model, the intent to simplify the modeling domain as much as possible without affecting significant alterations to the solution. The coupled model was created with the goal of permitting larger portions of the reactor core to be modeled at once without a significant sacrifice to solution integrity. As such, particular care is given to validating incorporated model simplifications. To the greatest extent possible, the decrease in solution time as well as computational cost are quantified versus the effects such gains have on the solution quality. A variant of the coupled model which sufficiently balances these three solution characteristics is presented alongside the more comprehensive 3D model for comparison and validation.

Simulating High Flux Isotope Reactor Core Thermal-Hydraulics Via Interdimensional Model Coupling

Simulating High Flux Isotope Reactor Core Thermal-Hydraulics Via Interdimensional Model Coupling PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A coupled interdimensional model is presented for the simulation of the thermal-hydraulic characteristics of the High Flux Isotope Reactor core at Oak Ridge National Laboratory. The model consists of two domains a solid involute fuel plate and the surrounding liquid coolant channel. The fuel plate is modeled explicitly in three-dimensions. The coolant channel is approximated as a twodimensional slice oriented perpendicular to the fuel plate s surface. The two dimensionally-inconsistent domains are linked to one another via interdimensional model coupling mechanisms. The coupled model is presented as a simplified alternative to a fully explicit, fully three-dimensional model. Involute geometries were constructed in SolidWorks. Derivations of the involute construction equations are presented. Geometries were then imported into COMSOL Multiphysics for simulation and modeling. Both models are described in detail so as to highlight their respective attributes in the 3D model, the pursuit of an accurate, reliable, and complete solution; in the coupled model, the intent to simplify the modeling domain as much as possible without affecting significant alterations to the solution. The coupled model was created with the goal of permitting larger portions of the reactor core to be modeled at once without a significant sacrifice to solution integrity. As such, particular care is given to validating incorporated model simplifications. To the greatest extent possible, the decrease in solution time as well as computational cost are quantified versus the effects such gains have on the solution quality. A variant of the coupled model which sufficiently balances these three solution characteristics is presented alongside the more comprehensive 3D model for comparison and validation.

Simulating HFIR Core Thermal Hydraulics Using 3D-2D Model Coupling

Simulating HFIR Core Thermal Hydraulics Using 3D-2D Model Coupling PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A model utilizing interdimensional variable coupling is presented for simulating the thermal hydraulic interactions of the High Flux Isotope Reactor (HFIR) core at Oak Ridge National Laboratory (ORNL). The model s domain consists of a single, explicitly represented three-dimensional fuel plate and a simplified two-dimensional coolant channel slice. In simplifying the coolant channel, and thus the number of mesh points in which the Navier-Stokes equations must be solved, the computational cost and solution time are both greatly reduced. In order for the reduced-dimension coolant channel to interact with the explicitly represented fuel plate, however, interdimensional variable coupling must be enacted along all shared boundaries. The primary focus of this paper is in detailing the collection, storage, passage, and application of variables across this interdimensional interface. Comparisons are made showing the general speed-up associated with this simplified coupled model.

COMSOL Simulations for Steady State Thermal Hydraulics Analyses of ORNL S High Flux Isotope Reactor

COMSOL Simulations for Steady State Thermal Hydraulics Analyses of ORNL S High Flux Isotope Reactor PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Simulation models for steady state thermal hydraulics analyses of Oak Ridge National Laboratory s High Flux Isotope Reactor (HFIR) have been developed using the COMSOL Multiphysics simulation software. A single fuel plate and coolant channel of each type of HFIR fuel element was modeled in three dimensions; coupling to adjacent plates and channels was accounted for by using periodic boundary conditions. The standard k- turbulence model was used in simulating turbulent flow with conjugate heat transfer. The COMSOL models were developed to be fully parameterized to allow assessing impacts of fuel fabrication tolerances and uncertainties related to low enriched uranium (LEU) fuel design and reactor operating parameters. Heat source input for the simulations was obtained from separate Monte Carlo N Particle calculations for the axially non-contoured LEU fuel designs at the beginning of the reactor cycle. Mesh refinement studies have been performed to calibrate the models against the pressure drop measured across the HFIR core.

High Flux Isotope Reactor System RELAP5 Input Model

High Flux Isotope Reactor System RELAP5 Input Model PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 320

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Book Description
A thermal-hydraulic computational model of the High Flux Isotope Reactor (HFIR) has been developed using the RELAP5 program. The purpose of the model is to provide a state-of-the art thermal-hydraulic simulation tool for analyzing selected hypothetical accident scenarios for a revised HFIR Safety Analysis Report (SAR). The model includes (1) a detailed representation of the reactor core and other vessel components, (2) three heat exchanger/pump cells, (3) pressurizing pumps and letdown valves, and (4) secondary coolant system (with less detail than the primary system). Data from HFIR operation, component tests, tests in facility mockups and the HFIR, HFIR specific experiments, and other pertinent experiments performed independent of HFIR were used to construct the model and validate it to the extent permitted by the data. The detailed version of the model has been used to simulate loss-of-coolant accidents (LOCAs), while the abbreviated version has been developed for the operational transients that allow use of a less detailed nodalization. Analysis of station blackout with core long-term decay heat removal via natural convection has been performed using the core and vessel portions of the detailed model.

Thermal Hydraulic Characteristics of Fuel Defects in Plate Type Nuclear Research Reactors

Thermal Hydraulic Characteristics of Fuel Defects in Plate Type Nuclear Research Reactors PDF Author: Isaac Thomas Bodey
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 150

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Book Description
Turbulent flow coupled with heat transfer is investigated for a High Flux Isotope Reactor (HFIR) fuel plate. The Reynolds Averaged Navier-Stokes Models are used for fluid dynamics and the transfer of heat from a thermal nuclear fuel plate using the Multi-physics code COMSOL. Simulation outcomes are compared with experimental data from the Advanced Neutron Source Reactor Thermal Hydraulic Test Loop. The computational results for the High Flux Isotope Reactor core system provide a more physically accurate simulation of this system by modeling the turbulent flow field in conjunction with the diffusion of thermal energy within the solid and fluid phases of the model domain. Recommendations are made regarding Nusselt number correlations and material properties for future thermal hydraulic modeling efforts.

Nuclear Reactor Thermal Hydraulics and Other Applications

Nuclear Reactor Thermal Hydraulics and Other Applications PDF Author: Donna Guillen
Publisher: BoD – Books on Demand
ISBN: 9535109871
Category : Technology & Engineering
Languages : en
Pages : 204

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Book Description
This book includes contributions from researchers around the world on numerical developments and applications to predict fluid flow and heat transfer, with an emphasis on thermal hydraulics computational fluid dynamics. Our ability to simulate larger problems with greater fidelity has vastly expanded over the past decade. The collection of material presented in this book augments the ever-increasing body of knowledge concerning the important topic of thermal hydraulics. Featured topics include coolant channel analysis, thermal hydraulic transport and mixing, as well as hydrodynamics and heat transfer processes. The contents of this book will interest researchers, scientists, engineers and graduate students.

Thermal Hydraulic Characteristics of Fuel Defects in Plate Type Nuclear Research Reactors

Thermal Hydraulic Characteristics of Fuel Defects in Plate Type Nuclear Research Reactors PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Turbulent flow coupled with heat transfer is investigated for a High Flux Isotope Reactor (HFIR) fuel plate. The Reynolds Averaged Navier-Stokes Models are used for fluid dynamics and the transfer of heat from a thermal nuclear fuel plate using the Multi-physics code COMSOL. Simulation outcomes are compared with experimental data from the Advanced Neutron Source Reactor Thermal Hydraulic Test Loop. The computational results for the High Flux Isotope Reactor core system provide a more physically accurate simulation of this system by modeling the turbulent flow field in conjunction with the diffusion of thermal energy within the solid and fluid phases of the model domain. Recommendations are made regarding Nusselt number correlations and material properties for future thermal hydraulic modeling efforts.

Thermal-hydraulic Simulation of Natural Convection Decay Heat Removal in the High Flux Isotope Reactor (HFIR) Using RELAP5 and TEMPEST

Thermal-hydraulic Simulation of Natural Convection Decay Heat Removal in the High Flux Isotope Reactor (HFIR) Using RELAP5 and TEMPEST PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The RELAP5/MOD2 code was used to predict the thermal-hydraulic behavior of the HFIR core during decay heat removal through boiling natural circulation. The low system pressure and low mass flux values associated with boiling natural circulation are far from conditions for which RELAP5 is well exercised. Therefore, some simple hand calculations are used herein to establish the physics of the results. The interpretation and validation effort is divided between the time average flow conditions and the time varying flow conditions. The time average flow conditions are evaluated using a lumped parameter model and heat balance. The Martinelli-Nelson correlations are used to model the two-phase pressure drop and void fraction vs flow quality relationship within the core region. Systems of parallel channels are susceptible to both density wave oscillations and pressure drop oscillations. Periodic variations in the mass flux and exit flow quality of individual core channels are predicted by RELAP5. These oscillations are consistent with those observed experimentally and are of the density wave type. The impact of the time varying flow properties on local wall superheat is bounded herein. The conditions necessary for Ledinegg flow excursions are identified. These conditions do not fall within the envelope of decay heat levels relevant to HFIR in boiling natural circulation. 14 refs., 5 figs., 1 tab.

Thermal Hydraulics Aspects of Liquid Metal Cooled Nuclear Reactors

Thermal Hydraulics Aspects of Liquid Metal Cooled Nuclear Reactors PDF Author: Ferry Roelofs
Publisher: Woodhead Publishing
ISBN: 0081019815
Category : Science
Languages : en
Pages : 464

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Book Description
Thermal Hydraulics Aspects of Liquid Metal cooled Nuclear Reactors is a comprehensive collection of liquid metal thermal hydraulics research and development for nuclear liquid metal reactor applications. A deliverable of the SESAME H2020 project, this book is written by top European experts who discuss topics of note that are supplemented by an international contribution from U.S. partners within the framework of the NEAMS program under the U.S. DOE. This book is a convenient source for students, professionals and academics interested in liquid metal thermal hydraulics in nuclear applications. In addition, it will also help newcomers become familiar with current techniques and knowledge. - Presents the latest information on one of the deliverables of the SESAME H2020 project - Provides an overview on the design and history of liquid metal cooled fast reactors worldwide - Describes the challenges in thermal hydraulics related to the design and safety analysis of liquid metal cooled fast reactors - Includes the codes, methods, correlations, guidelines and limitations for liquid metal fast reactor thermal hydraulic simulations clearly - Discusses state-of-the-art, multi-scale techniques for liquid metal fast reactor thermal hydraulics applications