bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of Inviscid Multi-Species Plasma Flow
Authors: Martin Alexandre , Reggio Marcelo , Tre´panier Jean-Yves
Published: August 2008

A multi-species solver for plasma at thermodynamical equilibrium is developed. A numerical scheme, based on Roe’s approximate Riemann solver, is implemented with some modification regarding averaged quantities. Treatments for perfect and real gas have been carried out. The real gas approach considers changes in the composition of the gas in local thermodynamics equilibrium assumptions. These models have been applied to the classical shock tube problem involving two different gases and air as a multi-species gas.
Numerical Simulation of Full Oxy-Fired Oscillating Combustion
Authors: Marin Ovidiu , Bugeat Benjamin , Till Marc , Louedin Olivier
Published: August 2008

Oscillating combustion represents a complex process, leading to significant improvements in high temperature industrial applications. Field demonstrations of the oscillating combustion technology have shown a significant reduction in NOx emissions, increased efficiency and improved operation. To date, no modeling work has been able to quantify these impacts of the technology. This effort presents the results of a numerical simulation study of oscillating combustion in a 450 kW pilot furnace. The combustion process involves a pipe-in-pipe natural gas-fired burner using exclusively oxygen as oxidant. The fuel is introduced into the combustion chamber periodically, given a certain amplitude and a time period, while the oxidant is introduced continuously. The transient numerical simulation uses the Air Liquide proprietary computational fluid dynamic software ATHENA™, analyzing the combustion process at incremental timesteps. The results reported here clearly explain the phenomena observed in the lab, as well as in field demonstrations. Detailed analysis of the mixing process between the fuel and oxidant, combustion of the reactants and heat transfer to the furnace walls is included. It is concluded that oscillating combustion represents a powerful solution to many industrial applications, and that modeling can play an important role in explaining the process, and in optimizing the system operation.
Hydrogen Distribution, Combustion and Detonation for H2 Risk Analysis in Large Facilities
Authors: Beccantini A. , Coulon N. , Dabbene F. , Gounand S. , Kudriakov S. , Magnaud J. P. , Paille`re H.
Published: August 2008

The French Atomic Energy Commission (C.E.A.) is developing a hydrogen risk analysis code (safety code) which incorporates both lumped-parameter and multi-dimensional formulations. In this paper we present the governing equations, numerical strategy and schemes used for the lumped parameter approach as well as for the multi-dimensional one. Typical numerical studies will be presented for hydrogen distribution and combustion applications in realistic large geometries.
Numerical Analysis of Interaction Between Plasma Jet and Flame in Supersonic Flow
Authors: Takita Kenichi
Published: August 2008

The ability of a plasma torch as an igniter in a supersonic flow for new engines was analyzed in various ways such as zero-dimensional analysis of ignition delay, one-dimensional analysis of burning velocity, and two-dimensional analysis of ignition phenomena with full chemistry, and so on. Problems in those analyses for accurate prediction of the performance of the plasma torch were herein discussed. The two-dimensional analysis was sufficient only for the ignition phenomena of the plasma torch. However, three-dimensional analysis is needed for simulations of flame spreading and flame-holding around the plasma jet after ignition.
Numerical Simulation of Non-Premixed Diffusion Flame and Reaction Product Aerosol Behavior in Liquid Metal Pool Combustion
Authors: Yamaguchi Akira , Tajima Yuji
Published: August 2008

A numerical methodology has been developed to solve a non-premixed diffusion flame under natural convection and applied to the calculation of the liquid sodium pool combustion experiment at various pool temperatures and oxygen concentrations. The computations reproduce the experimental observations concerning burning rate, flame temperature and flame height, consistently. The aerosol release rates are also in good agreement with the measurement. Dominant mechanisms of the mass and heat transfer are identified through the numerical simulation. An intrinsic feature is that the liquid sodium pool combustion is self-limited and negative feedback mechanism is at work Interaction among the thermal-hydraulics, chemical reaction and aerosol behavior plays an important role in the phenomena and it has been successfully analyzed by the numerical simulation. The present method can be used to understand sodium combustion phenomena and applied to the modeling of sodium pool combustion for safety analyses of liquid metal fast reactors. The numerical simulation is a useful tool because it can easily employ various conditions by changing parameters.
Numerical Modeling of Eccentric Jet Precombustor
Authors: Yezhu Sun
Published: August 2008

This thesis presents a numerical modeling on the cold flow field of the eccentric jet precombustor developed by the Institute of Mechanics, Chinese Academy of Sciences. The numerical modeling is to research the flow field structure of the eccentric jet precombustor, to study the factors which affect the recirculating region produced in the precombustor by eccentric jets and their affecting rules, then the results of the study will play the guiding and referenced roles in the optimizing design and operation of the eccentric jet precombustors. The effects of precombustor structure and operating parameters on flow field characteristics and possible effects on combustion stability in these two types of eccentric jet precombustor are numerically modeled, a detailed numerical analysis on the effects of eccentric jet precombustor’s structure include the shape of eccentric jet precombustor, the length of precombustor, the position, area, obliquity and shape of primary jet (main jet near center), the position and area of secondary jet (auxiliary jet near the wall), the momentum rate of primary jet to secondary jet etc. The code is used to solve the velocities fields, turbulent kinetic energy fields and other parameters. On this basis a comparison is made between the investigated cases and the most effective conditions are determined.
Validated 1D/3D Coupling Method to Solve Transient Flows in Internal Combustion Engines
Authors: Sinclair Rory , Schindler Peter , Strauss Tim
Published: August 2008

In this paper an improved numerical procedure [1] to calculate the gas dynamics within an automotive engine using hybrid 1D/3D models is presented. The hybrid models are solved using a coupled calculation of a 1D-finite differencing-code and a 3D-finite volume-code. The overall methodology is reviewed, emphasising new improvements to the averaging procedure. A simply method for the boundary velocity profile initialisation is discussed. Computational results from a hybrid model of a V6 TDI engine are discussed and compared to pressure measurements for three engine speeds.
Large Eddy Simulation of Turbulent Combustion Flows in Gas Turbine Combustor
Authors: Tominaga Takuji , Taniguchi Nobuyuki , Itoh Yuichi , Kobayashi Toshio
Published: August 2008

In this paper, Large Eddy Simulation (LES) and G-equation model based on flamelet concept are demonstrated in axially staged annular combustor of gas turbine engine. G-equation model is extended for combustion in a non-uniform equivalence ratio of premixed gas. Using this model, the simulations of the flame propagation are executed with different spatial distribution of the equivalence ratios. In order to compare the results, experiments for combustion and non-combustion flows in the modeled combustor are also performed. The flow field can be predicted by LES and be agreed with the experimental results essentially. The flame propagating behaviors depending on the equivalence ratios are represented by the extended G-equation model.
Using CFD to Improve Aero-Engine Air/Oil Separator Design
Authors: Eastwick Carol , Hibberd Stephen , Simmons Kathy , Wang Yi , Care Ian , Aroussi Abdelwahab
Published: August 2008

Within the transmission system of a commercial gas turbine engine the lubrication and cooling of shaft bearings is performed by oil injected into bearing chambers that are typically sealed with air-pressurised labyrinth seals. The subsequent air/oil mixture is scavenged from the bearing chamber with the oil being re-used, whilst the air is discharged overboard via an air/oil separator. Efficiency of separators is becoming a high priority to industry, with any loss of oil an environmental concern. To help improve the design of separators a computational model was created of an existing design and coupled two-phase CFD calculations were performed. A limited amount of experimental data, collected by particle image velocimetry (PIV) was available for validation.
Design Analysis of the Volumatic: A CFD and Experimental Study
Authors: Jalili Vahid , Patel Mayur K. , Bailey Christopher , Begg Steve , Versteeg Henk , Shrubb Ian , Hargrave Graham
Published: August 2008

The aim of this paper has been to describe the novel approach adopted in studying the flow field within the Volumatic. In this study a combination of engineering tools such as Computational Fluid Dynamics (CFD), Laser Doppler Anemometry (LDA) and Flow visualization techniques have been employed. The initial part of the study involved the use of CFD in modelling the drug entering the Volumatic. The CFD model was then validated against measurements made using LDA. The agreement obtained was very good; this was particularly encouraging as the CFD analysis was carried out some six months prior to the experimental study.
Three-Dimensional Flow Analysis in VFP Type Artificial Heart by Unstructured Grid
Authors: Kawano Satoyuki , Kato Takuma , Nakahashi Kazuhiro , Shirai Atsushi , Hayase Toshiyuki , Yambe Tomoyuki , Nitta Shin-Ichi , Hashimoto Hiroyuki
Published: August 2008

To effectively design the vibrating flow pump (VFP) for left ventricular assist device, the numerical codes were developed for three-dimensional blood flow based on the finite volume method. The numerical codes were also developed based on the artificial compressibility method by the use of unstructured grid. Three-dimensional numerical computations and the visualizations were made for flow patterns in the casing of VFP, which were closely connected with hemolysis and blood coagulation. We examined the three different inlet conditions, i.e., radial flow, flow considering the 2nd vibration mode of the jellyfish valve motion, and the swirling flow, to explore the suitable condition for preventing the hemolysis and the blood coagulation. It was found that the swirling flow could effectively decrease hemolysis. The effect of rheology model of the blood flow was also studied in detail.
CFD Analysis of the Behavior of Airborne Allergens in Carpeted and Uncarpeted Dwellings
Authors: Cicciarelli Bradley A. , Davidson David L. , Hart Edward H. , Peoples P. Robert
Published: August 2008

There is considerable concern today over indoor air quality (IAQ). The factors that influence IAQ may be numerous, and there is considerable research aimed at quantifying these factors. This research is of particular interest to industries that manufacture products used in residential and commercial dwellings, such as the carpet industry. With respect to carpet, there are various opinions about its role in IAQ, but little quantitative data. Much of the quantitative data that does exist either ignores or makes crude assumptions about the influence of fluid dynamics on the experimental observations. In this paper we discuss our use of Computational Fluid Dynamics (CFD) to model the transient behavior of airborne particles in dwellings with and without carpeted floors to quantify the impact of floor covering on IAQ. In particular, we discuss the theoretical considerations that are required to construct an accurate and practical CFD model that captures the correct fluid and particle dynamics, and present and summarize CFD predictions that account for the effects of HVAC systems, room geometry and virtual objects, such as people moving about the dwelling. In addition to getting the fluid and particle dynamics correct, there are two additional aspects of this problem that will be discussed. First, in order to draw reasonable conclusions about IAQ, a large number of simulations are required to capture the wide range of realistic dwelling conditions of interest. In order to perform these simulations in a timely manner, the process of building and meshing the geometry, specifying all relevant room conditions, conducting the simulation and interrogating the results has been automated by constructing a Digital Expert for the problem, wherein the user can automatically complete these tasks with little CFD expertise and no intervention. Second, it is essential to communicate the results of these simulations to lay audiences — the wide range of people interested in IAQ, including school boards, politicians and other government officials. We have developed a means of generating “Hollywood grade” animations that are more realistic in appearance than conventional CFD animations, and consequently more appealing and more readily understandable, but that reflect the correct fluid and particle dynamics. We believe that the integration of CFD with realistic animation capability will see greater applicability as our society becomes increasingly dependent on technology and decreasingly technically literate.
Forced Flow Heat and Mass Transfer to a Cylinder Surrounded by a Porous Material With Applications to NBC Protective Clothing
Authors: Sobera Michael P. , Kleijn Chris R. , Brasser Paul , Van den Akker Harry E. A.
Published: August 2008

Increased permeability of clothing material can reduce the heat load caused by Nuclear-Biological-Chemical (NBC) protective clothing, but implies reduced protection. The goal of the present work is to study the influence of the air permeability on human comfort and safety. A numerical study is presented of the air flow with heat and mass transfer around a cylinder, mimicking a human limb, placed in a turbulent external air flow and surrounded by protective clothing. The problem is described in terms of the relevant dimensionless numbers. The dependence of the flow field underneath the clothing and the heat and mass transfer to the limb are studied as a function of the Reynolds, Darcy and Damko¨hler numbers, which are a measure for the wind speed, clothing permeability and adsorptivity of the poisonous gas, respectively. The air flow simulations are validated with experiments, in which the flow field around a bare cylinder and in the space between a cylinder and its porous cover, is measured with LDA. Scaling rules for heat and mass transfer are presented.
Self-Excitation Vocalization Analyses of Vocal Chord Under Breathing Flow and Wide Frequency Change by Muscle Activation
Authors: Tsuta Toshio , Iwamoto Takeshi , Shimizu Toshiyuki , Egusa Daisuke
Published: August 2008

This paper presents some analyses and experiments on vocalizing mechanics in vocal chord due to the breathing flow, and their wide range of frequency change by varing the interior muscle activations. Three dimensional dynamic response of the hyperelastic and finite deformation body of the vocal chord and the interior muscles have been analysed at first and the exclusive FEM system has been developed. The eigen frequencies and vibration characteristics of the vocal chord are analysed by varing the activation level of the interior muscles. The Helmholtz equation of the breathing flow under transient state has been analysed to obtain the pressure pulsation characteristics behind the vocal chord during vocalizing of the source voice. Combining both approaches stated aboves, the mechanics of the self-exciting vibration of the vocal chord have been studied in detail using the root-locus approach. It is also found in the analysis and experiments that the frequency of the self-exciting vibration can be widely varied with the activation level of the interior muscle of the vocal chord, giving rise to a variety of frequency level of the source voice.
Computational Modelling and Simulation of Proton-Exchange Membrane Fuel Cells (Keynote)
Authors: Djilali N. , Berning T.
Published: August 2008

Fuel cells (FC’s) are electrochemical devices that convert directly into electricity the chemical energy of reaction of a fuel (usually hydrogen) with an oxidant (usually oxygen from ambient air). The only by-products in a hydrogen fuel cell are heat and water, making this emerging technology the leading candidate for quiet, zero emission energy production. Several types of fuel cell are currently undergoing intense research and development for applications ranging from portable electronics and appliances to residential power generation and transportation. The focus of this lecture is Proton-Exchange Membrane Fuel Cells (PEMFC’s). An electrolyte consisting of a “solid” polymer membrane, low operating temperatures (typically below 90 °C) and a relatively simple design combine to make PEMFC’s particularly well suited to automotive and portable applications. The operation of a fuel cell relies on electrochemical reactions and an array of coupled transport phenomena, including multi-component gas flow, two phase-flow, heat and mass transfer, phase change and transport of charged species. The transport processes take place in variety of media, including porous gas diffusion electrodes and polymer membranes. The fuel cell environment makes it impossible to measure in-situ the quantities of interest to understand and quantify these phenomena, and computational modelling and simulations are therefore poised to play a central role in the development and optimization of fuel cell technology. We provide an overview of the role of various transport phenomena in fuel cell operation and some of the physical and computational modelling challenges they present. The processes will be illustrated through examples of multi-dimensional numerical simulations of Proton-Exchange Membrane Fuel Cells. We close with a perspective on some of the many remaining challenges and future development opportunities.
Tools and Techniques for Modeling SOFC Fuel Cell Performance
Authors: Reich Alton J. , Das Rupak , Cole J. Vernon , Mazumder Sandip
Published: August 2008

Fuel cells have been utilized in certain specialized applications since the 1960’s, however the technology has recently been the focus of a broad research and development effort. The next 10 years will likely produce practical, affordable fuel cells that are applied in fixed power generation, automotive, and even powered bicycle applications. As the fuel cell becomes less of a research curiosity and more of an engineered commodity item, designers need tools to study and optimize the behavior of fuel cells. This paper discusses some of the questions that simulation can help fuel cell designers address.
Three-Dimensional Modeling of a Medium Size PEM Fuel Cell Stack: Thermal Effects and Electrical Performance
Authors: Kudriavtsev Vladimir , Das Rupak
Published: August 2008

In this extended abstract we describe self-consistent computational methodology developed to solve various engineering challenges arising during design and development of proton-exchange membrane based (PEM) fuel cell stacks. We extracted fundamental building block of the cell and developed several models, consistent with various levels of physical understanding of underlying mechanisms. Our proposed approach, when applied consistently allows relating global (cell and stack) and micro (individual channel) scale performances. This can be done for both thermo-flow and electrochemical parameters. We here report work-in-progress results. When research will be fully completed several sets of tabulated parameters and manual of fuel cell computations will be produced. CFD-ACE+ software package (CFDRC, Huntsville, AL) was used in this study.
Numerical Experiments for Flow Around a Ducted Tip Hydrofoil
Authors: Ingvarsdo´ttir Hildur , Ollivier-Gooch Carl , Green Sheldon I.
Published: August 2008

The performance and cavitation characteristics of marine propellers and hydrofoils are strongly affected by tip vortex behavior. A number of previous computational studies have been done on tip vortices, both in aerodynamic and marine applications. The focus, however, has primarily been on validating methods for prediction and advancing the understanding of tip-vortex formation in general, rather than showing effects of tip modifications on tip vortices. Studies of the most relevance to the current work include computational studies by Dacles-Mariani et al. (1995) and Hsiao and Pauley (1998, 1999). Daeles-Mariani et al. carried out interactively a computational and experimental study of the wingtip vortex in the near field using a full Navier-Stokes simulation, accompanied with the Baldwin-Barth turbulence model. Although they showed improvement over numerical results obtained by previous researchers, the tip vortex strength was underpredicted. Hsiao and Pauley (1998) studied the steady-state tip vortex flow over a finite-span hydrofoil, also using the Baldwin-Barth turbulence model. They were able to achieve good agreement in pressure distribution and oil flow pattern with experimental data and accurately predict vertical and axial velocities of the tip vortex core within the near-field region. Far downstream, however, the computed flow field was overly diffused within the tip vortex core. Hsiao and Pauley (1999) also carried out a computational study of the tip vortex flow generated by a marine propeller. The general characteristics of the flow were well predicted but the vortex core was again overly diffused.
Development of Ultrasonic Temperature Sensors for Ultra-High Temperature Measurement in Nuclear Reactor Vessel
Authors: Koo Kil-Mo , Ha Kwang-Soon , Park Rae-Joon , Kim Sang-Baik , Kim Hee-Dong , Kang Hee-Young
Published: August 2008

The temperature measurement of a very high temperature core melt is of importance in LAVA (lower-plenum Arrested Vessel Attack) experiment in which gap formation between core melt and the reactor lower head, and the effect of the gap on thermal behavior are to be measured. The existing temperature measurement techniques have some problems, where the thermocouple, one of the contact methods, is restricted to under 2000°C, and the infrared thermometry, one of the non-contact methods, is unable to measure an internal temperature and very sensitive to the interference from reacted gases. So, in order to solve these problems, the delay time of ultrasonic wavelets due to high temperature is suggested. One of the key initial conditions to be measured in LAVA is the initial corium melt temperature. To measure it, the LAVA measurement group has developed several kinds of UTS’s. As a first stage, a molten material temperature was measured up to 2314°C. Also, the optimization design of the UTS (ultrasonic temperature sensor) with persistence at the high temperature was suggested in this paper. And the utilization of the theory suggested in this paper and the efficiency of the developed system are certified by performing experiments.
Automatic Design of Hydropower Flows: The Draft Tube
Authors: Lindgren M. , Marjavaara B. D. , Lundstro¨m T. S.
Published: August 2008

The focus is set on a redesign of an existing draft tube by usage of an automated optimisation based on CFD calculations. By this method a design can be predicted in terms of a predefined objective function, here the pressure recovery factor. The design parameters used are based on spline-functions that are set under certain restrictions. One is that the new design should fit into the old one. The optimisation is performed with the Response Surface Method (RSM) implemented on the commercial code iSIGHT6.0. The flow simulations are carried out with the commercial code, CFX4, with the standard k-ε turbulence model and with boundary conditions based on detailed experimental data. With this set-up and the chosen parameterisation the highest value is found at the edge of the design space allowing for further improvements.
A Numerical Study of BWR Steam Separator
Authors: Terasaka Haruo , Shimizu Sensuke
Published: August 2008

An advanced numerical method based on two-fluid model of two-phase flow has been developed to simulate the swirling gas-liquid flow and the phase separation process in a Boiling Water Reactor separator. The goal is to correctly predict the performance of operating steam separator as well as new designs. The solution method present here is an extension of SIMPLEST scheme, a fully implicit scheme for single-phase flow analysis. It is robust and unconditionally stable, therefore enable us to use very large time step size. This feature is suitable for steady and/or slow transient flow analyses. Furthermore, it enhances numerical stability during rapid transient calculations. By employing this method, separator hydrodynamics around swirler were calculated.
CFD Analysis of Turbulent Flow in a Nuclear Fuel Bundle With Mixing Vane
Authors: In Wang Kee , Oh Dong Seok , Chun Tae Hyun
Published: August 2008

A computational fluid dynamics (CFD) analysis was performed to investigate the coolant mixing in a nuclear fuel bundle that is promoted by the mixing vane on the grid spacer. Single and multiple subchannels of one grid span of the fuel bundle were modeled to simulate a 5×5 rod array experiment with the mixing vane. The three-dimensional CFD models were generated by a structured multi-block method. The standard k-ε turbulence model was used in the current CFD simulation since it is practically useful and converges well for the complex turbulent flow in a nuclear fuel bundle. The CFD predictions of axial and lateral mean flow velocities showed a somewhat large difference from the experimental results near the spacer but represented the overall characteristics of coolant mixing well in a nuclear fuel bundle with the mixing vane. Comparison of single and multiple subchannel predictions shows good agreement of the flow characteristics in the central subchannel of the rod array. The simulation of multiple subchannels shows a slightly off-centered swirl in the peripheral subchannels due to the external wall of the rod array. It also shows no significant swirl and crossflow in the wall subchannels and the corner subchannels.
An Analysis of a Spent Fuel Transportation Cask Under Severe Fire Accident Conditions
Authors: Bajwa Christopher S.
Published: August 2008

Title 10 of the Code of Federal Regulations Part 71 section 73(c)(4), (10 CFR 71.73(c)(4)) requires that transportation packages used to ship radioactive material must be designed to resist an engulfing fire of a 30 minute duration and prevent release of radioactive material to the environment. In July, 2001, a derailed train carrying hazardous materials caught fire in a railroad tunnel in Baltimore, Maryland, and burned for several days. Although the occurrence of a fire of such duration during the shipment of spent nuclear fuel is unlikely, questions were raised about the performance of spent nuclear fuel casks under conditions similar to those experienced in the Baltimore tunnel fire incident. The U.S. Nuclear Regulatory Commission evaluates the performance of spent fuel transportation casks under accident conditions. The National Transportation Safety Board is responsible for investigating railroad accidents and identifying the probable cause(s) and offers recommendations for safety improvements. They are currently investigating the Baltimore tunnel fire accident. This paper assesses the performance of a spent fuel transportation cask with a welded canister under severe fire conditions. The paper describes the analytic model used for the assessment and presents a discussion of the preliminary results.
A Plutonium Storage Container Pressure Measurement Technique
Authors: Grim T. J. , Hensel S. J.
Published: August 2008

Plutonium oxide and metal awaiting final disposition are currently stored at the Savannah River Site (SRS) in crimp sealed food pack cans. Surveillances to ensure continued safe storage of the cans include periodic lid deflection measurements using a mechanical device. Trending the lid deflection measurements over time indicates whether tightly sealed cans are pressurizing or depressurizing. Both phenomena may result in reduced can integrity and ultimately in containment failure. Periodic lid deflection measurements have been taken on over 400 cans, and the vast majority indicate no changes in internal pressure. However, several cans were repackaged due to trends in lid deflection which indicated gradual but steady pressure decrease within the container over time. There have been no food can failures since the surveillance program has been instituted. Several cans have been repackaged which would have certainly failed.
A Pre-Shipment Gas Generation Test Using a Bell Jar
Authors: Rodrigues G. C. , Hensel S. J.
Published: August 2008

The primary purpose of a bell jar is to collect and measure out gassing from a container (e.g., food can) of plutonium bearing materials to evaluate potential pressurization within a shipping package containment vessel. The bell jar allows for testing of the actual cans to be shipped without repackaging or taking samples of the materials. Pressurization of the bell jar can be readily extrapolated to the conditions inside the shipping container containment vessel during a shipment. Bell jar testing is being used in conjunction with current plutonium surveillance techniques (lid deflection measuring) to demonstrate that the cans bearing plutonium material may be shipped safely across the Savannah River Site for processing. Statistical sampling of similar materials leverages the testing such that only population subsets need be tested. The pressurization (or depressurization) measured in the bell jar to date has been very small and of no concern from a shipping perspective.
Evaluation of Postulated Spent Fuel Container Handling Accidents Using Numerical Simulations
Authors: Morandin Greg D. , Ribbans David J.
Published: August 2008

Ontario Power Generation (OPG) is transferring irradiated fuel from its CANDU nuclear generating stations in Ontario Canada, that has been cooled for a minimum of 10 years in the Irradiated Fuel Bay (IFB), into Dry Storage Containers (DSC). The Picketing Used Fuel Dry Storage Facility has been in operation for 6 years and over 200 DSC’s have been loaded to date. During the loading operation a DSC is lifted out of the IFB and craned over a wall into a decontamination pit (DP). This operation requires that the lid of the DSC be in place before the container is removed from the IFB. A lid clamp is used, which sits around the perimeter of the lid and maintains the boundary between the mating lid and container flange plates, to ensure that the lid is retained under normal and abnormal conditions. In the event of a crane failure, there is a potential for the DSC to impact the intermediate wall between the IFB and the DP. This may result in the DSC toppling over the wall and either falling into the DP or toppling back into the IFB. Both the IFB and the DP have floor impact pads to prevent structural damage. The lid clamp must demonstrate the ability to maintain the containment boundary under these postulated accident scenarios. A finite element model of the Dry Storage Container and the proposed lid clamp has been developed to assess the structural integrity of the lid clamp design. The postulated accident scenarios consider are a 9.9 meter drop in a centre of gravity over top edge orientation, in a top down flat end orientation and a near side drop orientation onto an impact pad representative of the IFB pad. Only the centre of gravity and near side orientations are presented in this paper. The simulations were carried out on a DEC ALPHA workstation using an in-house three dimensional non-linear multi-purpose finite element code entitled H3DMAP version 6.
Dynamic Impact Analysis of a Type A Fissile Package Consisting of Thin Gage Mild Carbon Steel Components Arranged for High Energy Absorption
Authors: Wu Tsu-te , Leduc Daniel
Published: August 2008

The Savannah River Site (SRS) has a need to transport Highly Enriched Uranium (HEU) within site boundaries. A Type A fissile package design similar to the General Electric (GE) RA-3 and the Westinghouse PATRIOT packages has been selected for these shipments. This package design involves the use of light gage steel shapes, oriented to absorb energy from deformation and friction bearing contact surfaces, in between a thin gage mild carbon steel inner and outer shell. The RA-3 and the PATRIOT2 were both qualified by testing rather than analysis. To validate the SRS specific design, an advanced ABAQUS model of the package has been created to subject the package to dynamic impact analyses. The model was created to demonstrate the level of protection of the fuel assemblies and evaluate the impact absorbing capabilities of the package design concept.
A Technique for Dynamic Analyses of Containers With Locking-Ring Closures
Authors: Wu Tsu-te
Published: August 2008

The explicit method of the finite-element analysis is capable of analyzing the dynamic responses of a complex structure with complicated contact conditions. The method has been widely used in evaluating the dynamic responses of shipping package for radioactive materials. However, the previous analyses focused on the stresses and deformations of the structure components subjected impact loads and the possibility of the locking-ring closure separating from the drum body is not accounted for. The major difficulty for applying the explicit method to a container with a locking-ring closure is that the phenomenon of pre-loading a locking-ring closure is a static process; whereas, the explicit method involves the propagation of stress waves in the structure and thus is only applicable to dynamic analyses. The purpose of the present paper is to propose a technique that extends the application of the explicit finite-element method to the dynamic analysis of the container pre-loaded by a lock-ring. Unlike the conventional dynamic analysis by the explicit method that only needs one load step, the proposed technique requires three sequential procedure steps (not load steps) to complete an entire analysis. Furthermore, one procedure step may consist of two load steps. The paper discusses the procedures of the proposed technique in details. The application of the technique is illustrated by an example problem. The adequacy of the technique is also verified.
Effect of Temperature and Humidity on Crush Strength of Cellulose Fiberboard Assemblies
Authors: Smith Allen C. , Vormelker Philip R. , Chapman Glenn K. , Creech Greg D. , Khan Jamil , Khandkar Mir Zahedul Huq , Miller Kenneth W.
Published: August 2008

Cane fiberboard is widely used as the impact absorption and thermal insulation material in overpacks for radioactive materials shipping packages. The study described here investigated the properties of cane fiberboard assemblies under environmental conditions important to radioactive materials packaging applications. Tests were performed for loading perpendicular and parallel to the planes of the fiberboard sheets for both slow and impact strain rates, at high and low temperature and at high and low humidity. Under high temperature and high humidity conditions, the stress/strain response of the assemblies was close to the response at ambient conditions. However, for low temperature and impact strain rate conditions for specimens loaded parallel to the planes of the fiberboard sheets, an initial stress spike was found. The cause of this transient, high, initial stress was determined to be the stiffening effect of the glue layers used to bond the fiberboard sheets together.
Recent Progress on the Standardized DOE Spent Nuclear Fuel Canister
Authors: Morton D. Keith , Snow Spencer D. , Rahl Tom E. , Hill Tom J. , Morissette Richard P.
Published: August 2008

The Department of Energy (DOE) has developed a set of containers for the handling, interim storage, transportation, and disposal in the national repository of DOE spent nuclear fuel (SNF). This container design, referred to as the standardized DOE SNF canister or standardized canister, was developed by the Department’s National Spent Nuclear Fuel Program (NSNFP) working in conjunction with the Office of Civilian Radioactive Waste Management (OCRWM) and the DOE spent fuel sites. This canister had to have a standardized design yet be capable of accepting virtually all of the DOE SNF, be placed in a variety of storage and transportation systems, and still be acceptable to the repository. Since specific design details regarding the storage, transportation, and repository disposal of DOE SNF were not finalized, the NSNFP recognized the necessity to specify a complete DOE SNF canister design. This allowed other evaluations of canister performance and design to proceed as well as providing standardized canister users adequate information to proceed with their work. This paper is an update of a paper [1] presented to the 1999 American Society of Mechanical Engineers (ASME) Pressure Vessels and Piping (PVP) Conference. It discusses recent progress achieved in various areas to enhance acceptance of this canister not only by the DOE complex but also fabricators and regulatory agencies.
Electrochemical Behavior of Alloy 22 in 5 M CaCl2
Authors: Ilevbare G. O.
Published: August 2008

The corrosion resistance of Alloy 22 (UNS No. N06022) was studied in 5 M CaCl2 electrolyte at various temperatures. Potentiodynamic polarization was used to examine the electrochemical behavior and measure the key potentials. Alloy 22 was found to be susceptible to localized corrosion in this high-chloride [10 M Cl−] environment at temperatures as low as 60°C.
Passive Corrosion Behavior of Alloy 22 in Multi-Ionic Aqueous Environments
Authors: Lian Tiangan , Estill John C. , Hust Gary A. , Fix Dave V. , Rebak Raul B.
Published: August 2008

As part of proposed geological repository at Yucca Mountain, Nevada, Alloy 22 (Ni-22Cr-13Mo-3W-3Fe) has been chosen as the candidate material for a 2-cm outer layer on the high-level nuclear waste containers. During the repository period, the container materials will be subject to corrosion due to their exposure to multi-ionic aqueous environments. Although Alloy 22 has demonstrated excellent corrosion resistance, accumulation of a small, yearly corrosion rate for 10,000 or more years can be significant. When subjected to the conventional weight loss technique for corrosion studies, Alloy 22 requires many years to demonstrate a detectible weight loss. The goal of this research is to seek alternative techniques to determine a reasonably confident corrosion rate. This paper will discuss the latest experimental results using the potentiostatic technique to determine passive dissolution rates.
Test Results Using a Bell Jar to Measure Containment Vessel Pressurization
Authors: Hensel S. J. , Rodrigues G. C.
Published: August 2008

A bell jar is used to determine containment vessel pressurization due to outgassing of plutonium materials. Fifteen food cans containing plutonium bearing materials, including plutonium packaged in direct contact with plastic and plutonium contaminated enriched uranium oxide have been tested to date. As expected, minimal pressurization occurs and in some cases a slight depressurization has been observed. Linear extrapolation of the greatest pressurization observed in the bell jar to a typical drum shipping container (such as a 9975) has been performed. Pressurization from this particular can packaged for one year in a 9975 container is negligible.
Response of Conventional Ring Closures of Drum Type Packages to Regulatory Drop Tests With Application to the 9974/9975 Package
Authors: Blanton Paul S. , Smith Allen C.
Published: August 2008

DOT, DOE and NRC Type A and Type B radioactive material (RAM) transport packages routinely use industrial or military specification drums with conventional clamp ring closures as an overpack. Considerable testing has been performed on these type packages over the past 30 years. Observations from test data have resulted in various design changes and recommendations to the standard drum specification and use, enhancing the reliability of the overpack. Recently, performance of the 9975 conventional clamp ring closure design was questioned by the DOE Regulatory Authority. This paper highlights the observations of recent 9974 and 9975 package testing that led to redesign of the 9975, replacing the standard clamp ring closure with a bolted flange closure. In the course of this review and redesign effort, 18 package designs and approximately 100 Hypothetical Accident Condition (HAC) drops of various size and weight drum packages were evaluated. A trend was observed with respect to overpack lid failures for packages utilizing conventional ring closure. Based on this trend, a limit on the ratio of the internal weight to total package weight was identified, beyond which clamp ring closure failure may be expected.
Proposal for Qualification of Gas-Generating Radioactive Payloads for Transportation Within a Type B Package
Authors: Houghtaling T. K.
Published: August 2008

Characterization data describing radioactive materials (RAM) in storage are likely those associated with the processes that produced the materials or with the mission for which they were produced. Along with impurity data, often absent or unknown as a result of post-processing storage environment is moisture content. Radiolysis of moisture may lead to a hydrogen flammability hazard within a closed volume such as a storage can or a transportation package. This paper offers a practical means of qualifying payloads of unknown moisture content for shipment within Type B packaging, while supporting the DOE program to maintain radworker dose as low as reasonable achievable (ALARA). Specifically, the paper discusses part of a qualification program carried out at the Savannah River Site for onsite shipment of legacy RAM within the DDF-1 package. The DDF-1 is an onsite-only prototype of the currently certified 9975 package. Measurement of storage-can lid bulge can provide an upper bound for pressure within a storage can. Subsequent belljar testing can measure the rate of gas leakage from a storage can. These actions are shown sufficient to ensure that the performance of the 9975 containment vessels can accommodate 1) the deflagration energy from flammable gas mixtures within Normal Conditions of Transport, and 2) the consequences of a detonation shock wave within Hypothetical Accident Conditions.
Strain Gage Test Results of Band-Type Locking Rings for a Typical Drum Type Radioactive Material Package
Authors: McKeel Charles A. , Smith Allen C.
Published: August 2008

Band type closure rings are commonly used for securing the drum lid on radioactive material packages of lower weight classifications. Lid installation is achieved by placing the band around the perimeter of the lidded drum and tightening the single bolt in stages until a designated torque value is obtained. The band is subjected to heavy rapping with a soft hammer during installation to equilibrate the band strains around the drum perimeter. The study described here investigated the strain distributions in the band throughout the installation process. The results show that a uniform strain distribution is achieved during installation and that the hammering of the band aids in achieving the uniform distribution. The results of the strain levels after the drop test indicate that the locking rings maintain some pre-tension, even after severe targeted drops that crush a portion of the drum top.
Characterization of the Resistance of Alloy 22 to Stress Corrosion Cracking
Authors: King Kenneth J. , Estill John C. , Rebak Rau´l B.
Published: August 2008

In its current design, the high-level nuclear waste container includes an external layer of Alloy 22 (Ni-22Cr-13Mo-3W-3Fe). Since the containers may be exposed to multi-ionic aqueous environments over their lifetime, a potential degradation mode of the outer layer could be environmentally assisted cracking (EAC). The objective of the current research is to characterize the effect of applied potential and temperature on the susceptibility of Alloy 22 to EAC in simulated concentrated water (SCW) using the slow strain rate test (SSRT). Results show that Alloy 22 may suffer EAC at applied potentials approximately 400 mV more anodic than the corrosion potential (Ecorr).
Mechanical Properties and Corrosion Characteristics of Thermally Aged Alloy 22
Authors: Rebak Rau´l B. , Crook Paul
Published: August 2008

Alloy 22 (UNS N06022) is a candidate material for the external wall of the high-level nuclear waste containers for the potential repository site at Yucca Mountain. In the mill-annealed (MA) condition, Alloy 22 is a single face centered cubic phase. When exposed to temperatures on the order of 600°C and above for times higher than 1 h, this alloy may develop secondary phases that reduce its mechanical toughness and corrosion resistance. The objective of this work was to age Alloy 22 at temperatures between 482°C and 760°C for times between 0.25 h and 6,000 h and to study the mechanical and corrosion performance of the resulting material. Aging was carried out using wrought specimens as well as gas tungsten arc welded (GTAW) specimens. Mechanical and corrosion testing was carried out using ASTM standards. Results show that the higher the aging temperature and the longer the aging time, the lower the impact toughness of the aged material and the lower its corrosion resistance. However, extrapolating both mechanical and corrosion laboratory data predicts that Alloy 22 will remain corrosion resistant and mechanically robust tbr the projected lifetime of the waste container.
Effect of Insolation Boundary Conditions on Type B Package Internal Temperatures
Authors: Hovingh J. , Shah V.
Published: August 2008

The prescription for initial and final conditions for a thermal accident for Type B packages is different for each of the regulations governing Type B packages for the transportation of radioactive material. This paper presents an analytical method for estimating the effect of the boundary conditions on post-fire peak internal package temperatures. Results are given for several boundary conditions for a Type B, drum-type package.
A Standard for Storage and Transport of Damaged Spent Nuclear Fuel
Authors: Lake William H.
Published: August 2008

The paper provides background on the Nuclear Regulatory Commission’s April 1984, Director’s Decision on failed and damaged spent fuel, DD-84-9. Examples of damaged fuel transports and the recently issued NRC interim staff guidance on damaged SNF, ISG-1, are discussed. These preliminary topics form the basis for discussion of the need, development and status of an American National Standards Institute standard, ANSI N14.33, for damaged spent fuel.
Transfer Cask Assembly: Onsite Transfer of K-Basin Fuel at Hanford
Authors: Jensen Donald A. , Kee Andrew T. , Johnson Robert A. , Noss Philip W.
Published: August 2008

Packaging Technology, Inc. was awarded a contract for the design and fabrication of a unique 18.5-ton transportation system to be used on-site at Hanford, WA. Unique aspects include rectangular cask geometry, solid 7”-thick stainless steel construction, hinged lid with remotely operable quick release locking mechanism. The lid maintains shielding and material confinement integrity after hypothetical accident conditions, and is equipped with a hydrogen venting system. This paper presents how the project requirements were translated into a successful design, and includes a brief discussion of a confirmation test program.