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Nondestructive Evaluation Techniques for Silicon Carbide Heat-Exchanger Tubes : Annual Report, October 1977-September 1978

Description: This report discusses the adequacy of several nondestructive evaluation techniques for the detection of flaws in silicon carbide heat-exchanger tubing. Experimental results have been obtained for conventional ultrasonic testing, acoustic microscopy, conventional and dye-enhanced radiography, holographic interferometry, infrared scanning and internal-friction measurements.
Date: March 1979
Creator: Kupperman, D. S.; Yuhas, D.; Sciammarella, Cesar A.; Lapinski, N. P. & Fiore, N. F.
Partner: UNT Libraries Government Documents Department

Failure analysis and surety design of composite patching systems.

Description: This work presents an experimental evaluation of patch repair of solid laminated composites. The study was focused on destructive and nondestructive tests of full-scale repaired panels under static tension loading conditions. The testing program consisted of ten panels: three pristine, three damaged, three repaired and one repaired with mismatched fiber orientation patch. The evaluated panels were (300 mm x 675 mm) in size and consisted of 6-ply ((-60 /60/0){sub s}) quasi-isotropic laminates. The destructive tests were performed by North Carolina A&T State University and the nondestructive tests were performed by Iowa State University using Pulse-echo C-scan, Air coupled TTU and Auto-Tap. Sandia National Laboratories validated the NDT tests by implementing NDE field methods. Based on the evaluation performed in this study, it appears that the patch repair is an effective means in retrofitting damaged solid composite laminates.
Date: August 1, 2004
Creator: Hamoush, Sameer (North Carolina A&T State University, Greensboro, NC)
Partner: UNT Libraries Government Documents Department

A Study to Develop a Curriculum in Industrial Destructive Testing Procedures for Ferrous and Non-Ferrous Metals at the University Level

Description: The problem of this study was to develop a curriculum based on present destructive testing procedures used in industry dealing with the mechanical properties of ferrous and non-ferrous metals, and to organize the curriculum at the university level.
Date: May 1971
Creator: Geary, Michael Robert
Partner: UNT Libraries

Stress corrosion cracking tests using double-cantilever-beam specimens

Description: Although a wide variety of degradation modes can occur in aqueous environments for corrosion-resistant metallic materials, localized corrosion such as pitting corrosion, crevice corrosion, SCC, and hydrogen embrinlement (HE) is considered to be the primary mode. The evaluation of the susceptibility of candidate corrosion-resistant container materials to pitting and crevice corrosion is well underway using electrochemical polarization techniques described in the Activity Plan E-20-43144. The proposed activity (E-20-56) is aimed at evaluating the SCC behavior of these materials in susceptible environments using the linearelastic-fracture-mechanics (LEFM) concept. The mechanical driving force for crack growth, or the stress distribution at the crack tip is quantified by the stress intensity factor, K, for the specific crack and loading geometry. The critical stress intensity factor for SCC, K<sub>ISCC</sub> for candidate materials will be evaluated in environments of interest, and their comparisons will be made to select the waste package inner container material having an optimum SCC resistance.
Date: October 25, 1996
Creator: Roy, A.
Partner: UNT Libraries Government Documents Department


Description: Applications in high energy physics accelerators and other fields require the use of thousands of superconducting RF (SRF) cavities that are made of high purity Nb material and the purity of niobium is critical for these cavities to reach the highest accelerating fields. Tantalum is the most prolific of metal inclusions, which can cause thermal breakdown and prevent the cavities from reaching their theoretical performance limits of 45-50 MV/m, and DOE Labs are searching for a technology that could detect small impurities in superconducting Nb sheets reaching the highest possible accelerating fields. The proposed innovative SQUID-based Nondestructive system can scan Niobium sheets used in the manufacturing of SRF cavities with both high speed and high resolution. A highly sensitive SQUID system with a gradiometer probe, non-magnetic dewar, data acquisition system, and a scanning system will be developed for fast detection of impurities in planar Nb sheets. In phase I, we will modify our existing SQUID-based eddy current system to detect 100 micron size Ta defects and a great effort will focus on achieving fast scanning of a large number of niobium sheets in a shorter time and with reasonable resolution. An older system operated by moving the sample 1 mm, stopping and waiting for 1-2 seconds, then activating a measurement by the SQUID after the short settle time is modified. A preliminary designed and implemented a SQUID scanning system that is fast and is capable of scanning a 30 cm x 30 cm Nb sheet in 15 minutes by continuously moving the table at speeds up to 10 mm/s while activating the SQUID at 1mm interval is modified and reached the Phase I goal of 100mm resolution. We have successfully demonstrated the feasibility that a fast speed SQUID scanner without sacrificing the resolution of detection can be done, and a ...
Date: June 8, 2008
Partner: UNT Libraries Government Documents Department


Description: The Savannah River Site (SRS) stores packages containing plutonium (Pu) materials in the K-Area Complex (KAC). The Pu materials are packaged per the DOE 3013 Standard and stored within Model 9975 shipping packages in KAC. The KAC facility DSA (Document Safety Analysis) [1] credits the Model 9975 package to perform several safety functions, including criticality, impact resistance, containment, and fire resistance to ensure the plutonium materials remain in a safe configuration during normal and accident conditions. The Model 9975 package is expected to perform its safety function for at least 12 years from initial packaging. The DSA recognizes the degradation potential for the materials of package construction over time in the KAC storage environment and requires an assessment of materials performance to validate the assumptions of the analysis and ultimately predict service life. As part of the comprehensive Model 9975 package surveillance program [2-3], destructive examination of package 9975-00600 was performed following field surveillance in accordance with Reference [4]. Field surveillance of the Model 9975 package in KAC included nondestructive examination of the drum, fiberboard, lead shield and containment vessels [5]. Results of the field surveillance are provided in Attachment 1. Destructive and non-destructive examinations have been performed on specified components of shipping package 9975-00600. For those attributes that were also measured during the field surveillance, no significant changes were observed. Three conditions were identified that do not meet inspection criteria. These conditions are subject to additional investigation and disposition by the Surveillance Program Authority. The conditions include: (1) The lead shield was covered with a white corrosion layer; (2) The lead shield height dimension exceeded drawing requirements; and (3) Fiberboard thermal conductivity in the axial direction exceeded the specified range. The Surveillance Program Authority was notified of these conditions. All other observations and test results met identified criteria, or ...
Date: October 29, 2007
Creator: Daugherty, W
Partner: UNT Libraries Government Documents Department

Interpretation of data obtained from non-destructive and destructive post-test analyses of an intact-core column of culebra dolomite

Description: The U.S. Department of Energy (DOE) has been developing a nuclear waste disposal facility, the Waste Isolation Pilot Plant (WIPP), located approximately 42 km east of Carlsbad, New Mexico. The WIPP is designed to demonstrate the safe disposal of transuranic wastes produced by the defense nuclear-weapons program. Pefiormance assessment analyses (U.S. DOE, 1996) indicate that human intrusion by inadvertent and intermittent drilling for resources provide the only credible mechanisms for significant releases of radionuclides horn the disposal system. These releases may occur by five mechanisms: (1) cuttings, (2) cavings, (3) spallings, (4) direct brine releases, and (5) long- term brine releases. The first four mechanisms could result in immediate release of contaminant to the accessible environment. For the last mechanisq migration pathways through the permeable layers of rock above the Salado are important, and major emphasis is placed on the Culebra Member of the Rustler Formation because this is the most transmissive geologic layer in the disposal system. For reasons of initial quantity, half-life, and specific radioactivity, certain isotopes of T~ U, Am, and Pu would dominate calculated releases from the WIPP. In order to help quantifi parameters for the calculated releases, radionuclide transport experiments have been carried out using five intact-core columns obtained from the Culebra dolomite member of the Rustler Formation within the Waste Isolation Pilot Pknt (WIPP) site in southeastern New Mexico. This report deals primarily with results of analyses for 241Pu and 241Am distributions developed during transport experiments in one of these cores. All intact-core column transport experiments were done using Culebra-simukmt brine relevant to the core recovery location (the WIPP air-intake shaft - AK). Hydraulic characteristics (i.e., apparent porosity and apparent dispersion coefficient) for intact-core columns were obtained via experiments using conservative tracer `Na. Elution experiments carried out over periods of a few days with ...
Date: September 1, 1998
Creator: Lucero, Daniel L. & Perkins, W. George
Partner: UNT Libraries Government Documents Department

Report on fulfillment of research work: Impact studies on water-filled cylinders

Description: The purpose of this work is the experimental determination of partial criteria of destruction of metal, liquid-filled cylinders (LFC hereafter) loaded by high-velocity, compact steel impactors, or strikers. The required list of partial destruction criteria has been substantiated in two stages. At the first, preliminary stage, in the course of experiment planning the widest list of these criteria was determined proceeding from existing ideas of LFC destruction. At the second stage, when initial experiments have been performed, some of partial criteria can be excluded from the list and the others can be modified. One can also suppose, that some new partial criteria will appear.
Date: December 31, 1995
Partner: UNT Libraries Government Documents Department

High-flux source of fusion neutrons for material and component testing

Description: The inner part of a fusion reactor will have to operate at very high neutron loads. In steady-state reactors the minimum fluence before the scheduled replacement of the reactor core should be at least l0-15 Mw.yr/m<sup>2</sup>. A more frequent replacement of the core is hardly compatible with economic constraints. A most recent summary of the discussions of these issues is presented in Ref. [l]. If and when times come to build a commercial fusion reactor, the availability of information on the behavior of materials and components at such fluences will become mandatory for making a final decision. This makes it necessary an early development and construction of a neutron source for fusion material and component testing. In this paper, we present information on one very attractive concept of such a source: a source based on a so called Gas Dynamic Trap. This neutron source was proposed in the mid 1980s (Ref. [2]; see also a survey [3] with discussion of the early stage of the project). Since then, gradual accumulation of the relevant experimental information on a modest-scale experimental facility GDT at Novosibirsk, together with a continuing design activity, have made initial theoretical considerations much more credible. We believe that such a source can be built within 4 or 5 years. Of course, one should remember that there is a chance for developing steady-state reactors with a liquid (and therefore continuously renewable) first wall [4], which would also serve as a tritium breeder. In this case, the need in the neutron testing will become less pressing. However, it is not clear yet that the concept of the flowing wall will be compatible with all types of steady-state reactors. It seems therefore prudent to be prepared to the need of a quick construction of a neutron source. It should also be ...
Date: January 7, 1999
Creator: Baldwin, D. E.; Hooper, E. B.; Ryutov, D. D. & Thomassen, K. I.
Partner: UNT Libraries Government Documents Department

Use of inelastic analysis to determine the response of packages to puncture accidents

Description: The accurate analytical determination of the response of radioactive material transportation packages to the hypothetical puncture accident requires inelastic analysis techniques. Use of this improved analysis method recudes the reliance on empirical and approximate methods to determine the safety for puncture accidents. This paper will discuss how inelastic analysis techniques can be used to determine the stresses, strains and deformations resulting from puncture accidents for thin skin materials with different backing materials. A method will be discussed to assure safety for all of these types of packages.
Date: August 1, 1996
Creator: Ammerman, D.J. & Ludwigsen, J.S.
Partner: UNT Libraries Government Documents Department

Drum drop test report

Description: Testing was performed to determine actual damage to drums when dropped from higher than currently stacked elevations. The drum configurations were the same as they are placed in storage; single drums and four drums banded to a pallet. Maximum drop weights were selected based on successful preliminary tests. Material was lost from each of the single drum tests while only a small amount of material was lost from one of the pelletized drums. The test results are presented in this report. This report also provides recommendations for further testing to determine the appropriate drum weight which can be stored on a fourth tier.
Date: February 28, 1995
Creator: McBeath, R.S.
Partner: UNT Libraries Government Documents Department

Numerical Simulations of Two Wildfire Events Using a Combined Modeling System (HIGRAD/BEHAVE)

Description: The ability to accurately forecast the spread of a wildfire would significantly reduce human suffering and loss of life, the destruction of property, and expenditures for assessment and recovery. To help achieve this goal we have developed a model which accurately simulates the interactions between winds and the heat source associated with a wildfire. We have termed our new model HIGRAD or High resolution model for strong GRA-Dient applications. HIGRAD employs a sophisticated numerical technique to prevent numerical Oscillations from occurring in the vicinity of the lire. Of importance for fire modeling, HIGRAD uses a numerical technique which allows for the use of a compressible equation set, but without the time-step restrictions associated with the propagation of sound-waves.
Date: December 31, 1997
Creator: Reisner, J.; Bossert, J. & Winterkamp, J.
Partner: UNT Libraries Government Documents Department

Stress-temperature-lifetime response of nicalon fiber-reinforced SiC composites in air

Description: Time-to-failure tests were conducted in four-point flexure and in air as a function of stress levels and temperatures to study the lifetime response of various Nicalon fiber-reinforced SiC (designated as Nic/SiC) composites with a graphitic interfacial coating. The results indicated that all of the Nic/SiC composites exhibit a similar stress-dependent failure at applied stress greater than a threshold value. In this case, the lifetimes of the composites increased with decrease in both stress level and test temperature. The lifetime of the composites appeared to be relatively insensitive to the thickness of graphitic interface layer and was enhanced somewhat by the addition of oxidation inhibitors. Electron microscopy and oxidation studies indicated that the life of the Nic/SiC composites was governed by the oxidation of the graphitic interfaces and the on of glass(es) in composites due to the oxidation of the fiber and matrix, inhibitor phases.
Date: February 1996
Creator: Lin, Hua-Tay & Becher, P. F.
Partner: UNT Libraries Government Documents Department

The development of an enhanced strain measurement device to support testing of radioactive material packages

Description: Radioactive material package designers use structural testing to verify and demonstrate package performance. A major part of evaluating structural response is the collection of reliable instrumentation measurement data. Over the last four decades, Sandia National Laboratories (SNL) has been actively involved in the development, testing, and evaluation of measurement devices for a broad range of applications, resulting in the commercialization of several measurement devices commonly used today. SNL maintains an ongoing program sponsored by the US Department of Energy (DOE) to develop and evaluate measurement devices to support testing of packages used to transport radioactive or hazardous materials. The development of the enhanced strain measurement device is part of this program.
Date: December 31, 1995
Creator: Uncapkher, W.L. & Arviso, M.
Partner: UNT Libraries Government Documents Department

Impact limiter design for a lightweight tritium hydride vessel transport container

Description: Sandia National Laboratories (SNL) has designed an impact-limiting system for a small, lightweight radioactive material shipping container. The Westinghouse Savannah River Company (WSRC) is developing this Type B package for the shipment of tritium, replacing the outdated LP-50 shipping container. Regulatory accident resistance requirements for Type B packages, including this new tritium package, are specified in 10 CFR 71 (NRC 1983). The regulatory requirements include a 9-meter free drop onto an unyielding target, a 1-meter drop onto a mild steel punch, and a 30-minute 800{degrees} C fire test. Impact limiters are used to protect the package in the free-drop accident condition in any impact orientation without hindering the package`s resistance to the thermal accident condition. The overall design of the new package is based on a modular concept using separate thermal shielding and impact mitigating components in an attempt to simplify the design, analysis, test, and certification process. Performance requirements for the tritium package`s limiting system are based on preliminary estimates provided by WSRC. The current tritium hydride vessel (THV) to be transported has relatively delicate valving assemblies and should not experience acceleration levels greater than approximately 200 g`s. A thermal overpack and outer stainless steel shell, to be designed by WSRC, will form the inner boundary of the impact-limiting system (see Figure 1). The mass of the package, including cargo, inner container, thermal overpack, and outer stainless steel shell (not including impact limiters) should be approximately 68 kg. Consistent with the modular design philosophy, the combined thermal overpack and containment system should be considered essentially rigid, with the impact limiters incurring all deformation.
Date: December 31, 1995
Creator: Harding, D.C.; Longcope, D.B. & Neilsen, M.K.
Partner: UNT Libraries Government Documents Department

Integration of finite element analysis and numerical optimization techniques for RAM transport package design

Description: Type B radioactive material transport packages must meet strict Nuclear Regulatory Commission (NRC) regulations specified in 10 CFR 71. Type B containers include impact limiters, radiation or thermal shielding layers, and one or more containment vessels. In the past, each component was typically designed separately based on its driving constraint and the expertise of the designer. The components were subsequently assembled and the design modified iteratively until all of the design criteria were met. This approach neglects the fact that components may serve secondary purposes as well as primary ones. For example, an impact limiter`s primary purpose is to act as an energy absorber and protect the contents of the package, but can also act as a heat dissipater or insulator. Designing the component to maximize its performance with respect to both objectives can be accomplished using numerical optimization techniques.
Date: December 31, 1995
Creator: Harding, D.C.; Eldred, M.S. & Witkowski, W.R.
Partner: UNT Libraries Government Documents Department

Simulation and analysis of the plutonium oxide/metal storage containers subject to various loading conditions

Description: The structural and functional requirements of the Plutonium Oxide/Metal Storage Containers are specified in the Report ``Complex 21 Plutonium Storage Facility Material Containment Team Technical Data Report`` [Complex 21, 1993]. There are no existing storage containers designed for long term storage of plutonium and current codes, standards or regulations do not adequately cover this case. As there is no extensive experience with the long term (50+ years) storage of plutonium, the design of high integrity storage containers must address many technical considerations. This analysis discusses a few potential natural phenomena that could theoretically adversely affect the container integrity over time. The plutonium oxide/metal storage container consists of a primary containment vessel (the outer container), a bagless transfer can (the inner container), two vertical plates on top of the primary containment vessel, a circular plate (the flange) supported by the two plates, tube for gas sampling operations mounted at the center of the primary containment vessel top and a spring system being inserted in the cavity between the primary containment vessel and the cap of the bagless transfer can. The dimensions of the plutonium oxide/metal storage container assembly can be found in Figure 2-1. The primary container, the bagless transfer can, and all the attached components are made of Type 304L stainless steel.
Date: May 1, 1995
Creator: Gong, C. & Miller, R.F.
Partner: UNT Libraries Government Documents Department

Analysis and testing of rupture of steam generator tubing with flaws.

Description: A high-temperature (300 C), high-pressure (18 MPa), and high-leak rate (1500 L/min) facility, and a room temperature, high-pressure (52 MPa) test facility were used to test flawed steam generator tubes. Single and multiple rectangular flaws were fabricated by electro-discharge machining on the outside surface of the tubes. This paper briefly reviews analytical methods for predicting ligament rupture and unstable burst of tubes with single and multiple rectangular flaws. Test data are presented to validate the failure models. The ligament rupture pressure of specimens with multiple flaws predicted by an equivalent rectangular crack method agree fairly well with measured data.
Date: February 8, 2001
Creator: Majumdar, S.; Kasza, K. S.; Park, J. Y. & Hanna, J. A.
Partner: UNT Libraries Government Documents Department

Non-Destructive Evaluation of Thermal Spray Coating Interface Quality by Eddy Current Method

Description: Thermal spray coating is usually applied through directing molten or softened particles at very high velocities onto a substrate. An eddy current non-destructive inspection technique is presented here for thermal spray coating interface quality characterization. Several high-velocity-oxy-fuel (HVOF) coated steel plates were produced with different surface preparation conditions before applying the coating, e.g., grit-blasted surface, wire-brush cleaned surface, and a dirty surface. A quad-frequency eddy current probe was used to manually scan over the coating surface to evaluate the bonding quality. Experimental results show that the three surface preparation conditions can be successfully differentiated by looking into the impedance difference observed from the eddy current probe. The measurement is fairly robust and consistent. More specimens are also prepared with variations of process parameters, such as spray angle, stand-off distance, and application of corrosion protective sealant, etc. They are blindly tested to evaluate the reliability of the eddy current system. Quantitative relations between the coating bond strength and the eddy current response are also established with the support of destructive testing. This non-contact, non-destructive, easy to use technique has the potential for evaluating the coating quality immediately after its application so that any defects can be corrected immediately.
Date: May 26, 2006
Creator: B.Mi; Zhao, X. & Bayles, R.
Partner: UNT Libraries Government Documents Department

Energy absorption in aluminum extrusions for a spaceframe chassis

Description: This work describes the design, finite-element analysis, and verifications performed by LLNL and Kaiser Aluminum for the prototype design of the CALSTART Running Chassis purpose-built electric vehicle. Component level studies, along with our previous experimental and finite-element works, provided the confidence to study the crashworthiness of a complete aluminum spaceframe. Effects of rail geometry, size, and thickness were studied in order to achieve a controlled crush of the front end structure. These included the performance of the spaceframe itself, and the additive effects of the powertrain cradle and powertrain (motor/controller in this case) as well as suspension. Various design iterations for frontal impact at moderate and high speed are explored.
Date: September 19, 1994
Creator: Logan, R.W.; Perfect, S.A. & Parkinson, R.D.
Partner: UNT Libraries Government Documents Department

Dynamic pulse buckling of cylindrical shells under axial impact: A benchmark study of 2D and 3D finite element calculations

Description: A series of tests investigating dynamic pulse buckling of a cylindrical shell under axial impact is compared to several 2D and 3D finite element simulations of the event. The purpose of the work is to investigate the performance of various analysis codes and element types on a problem which is applicable to radioactive material transport packages, and ultimately to develop a benchmark problem to qualify finite element analysis codes for the transport package design industry. During the pulse buckling tests, a buckle formed at each end of the cylinder, and one of the two buckles became unstable and collapsed. Numerical simulations of the test were performed using PRONTO, a Sandia developed transient dynamics analysis code, and ABAQUS/Explicit with both shell and continuum elements. The calculations are compared to the tests with respect to deformed shape and impact load history.
Date: April 1, 1995
Creator: Hoffman, E.L. & Ammerman, D.J.
Partner: UNT Libraries Government Documents Department