Development and application of NDE methods for monolithic and continuous fiber ceramic matrix composites. (open access)

Development and application of NDE methods for monolithic and continuous fiber ceramic matrix composites.

Monolithic structural ceramics and continuous fiber ceramic matrix composites (CMCs) are being developed for application in many thermally and chemically aggressive environments where structural reliability is paramount. We have recently developed advanced nondestructive evaluation (NDE) methods that can detect distributed ''defects'' such as density gradients and machining-induced damage in monolithic materials, as well as delamination, porosity, and throughwall cracks, in CMC materials. These advanced NDE methods utilize (a) high-resolution, high-sensitivity thermal imaging; (b) high-resolution X-ray imaging; (c) laser-based elastic optical scattering; (d) acoustic resonance; (e) air-coupled ultrasonic methods; and (f) high-sensitivity fluorescent penetrant technology. This paper discusses the development and application of these NDE methods relative to ceramic processing and ceramic components used in large-scale industrial gas turbines and hot gas filters for gas stream particulate cleanup.
Date: May 21, 1999
Creator: Ellingson, W. A.
Object Type: Article
System: The UNT Digital Library
The effects of neutron irradiation on fracture toughness of austenitic stainless steels. (open access)

The effects of neutron irradiation on fracture toughness of austenitic stainless steels.

Austenitic stainless steels are used extensively as structural alloys in reactor pressure vessel internal components because of their superior fracture toughness properties. However, exposure to high levels of neutron irradiation for extended periods leads to significant reduction in the fracture resistance of these steels. This paper presents results of fracture toughness J-R curve tests on four heats of Type 304 stainless steel that were irradiated to fluence levels of {approx}0.3 and 0.9 x 10{sup 21} n cm{sup {minus}2} (E >1 MeV) at {approx}288 C in a helium environment in the Halden heavy water boiling reactor. The tests were performed on 1/4-T compact tension specimens in air at 288 C; crack extensions were determined by both DC potential and elastic unloading compliance techniques.
Date: May 21, 1999
Creator: Chopra, O. K.; Gruber, E. E. & Shack, W. J.
Object Type: Article
System: The UNT Digital Library
Allocating resources and building confidence in public-safety decisions for nuclear waste sites (open access)

Allocating resources and building confidence in public-safety decisions for nuclear waste sites

There are three basic ways to protect the public from the hazards of exposure to radionuclides in nuclear waste: completely contain the waste; limit the rate at which radionuclides are released; and, once radionuclides are released, minimize their impact by reducing concentrations and retarding transport. A geologic repository system that implements all three provides maximum protection for the public: if one element fails, the others serve to protect. This is ''defense-in-depth.'' Demonstrating confidence in the ability of a designed system to provide the requisite safety to the public must rely on a combination of the following aspects relating to engineered and natural system components: 1 Knowledge or understanding of properties and processes 2 Uniformity of (or ability to understand or control) the range of variability associated with each component 3 Experience over time This paper proposes a tool based on defining a ''confidence region'' determined by these three essential aspects of confidence. The defense-in-depth decision-making tool described identifies the portion of the ultimate confidence region that is not well demonstrated and indicates where there is potential for changing a specific component's confidence region, therefore providing in-formation for decisions on emphasis--either for demonstrating performance or for focusing on further studies. The …
Date: May 21, 1999
Creator: Lew, K L & Wilder, D G
Object Type: Article
System: The UNT Digital Library
Welding metallurgy of nickel alloys in gas turbine components (open access)

Welding metallurgy of nickel alloys in gas turbine components

Materials for gas turbine engines are required to meet a wide range of temperature and stress application requirements. These alloys exhibit a combination of creep resistance, creep rupture strength, yield and tensile strength over a wide temperature range, resistance to environmental attack (including oxidation, nitridation, sulphidation and carburization), fatigue and thermal fatigue resistance, metallurgical stability and useful thermal expansion characteristics. These properties are exhibited by a series of solid-solution-strengthened and precipitation-hardened nickel, iron and cobalt alloys. The properties needed to meet the turbine engine requirements have been achieved by specific alloy additions, by heat treatment and by thermal mechanical processing. A thorough understanding of the metallurgy and metallurgical processing of these materials is imperative in order to successfully fusion weld them. This same basic understanding is required for repair of a component with the added dimension of the potential effects of thermal cycling and environmental exposure the component will have endured in service. This article will explore the potential problems in joining and repair welding these materials.
Date: May 21, 1997
Creator: Lingenfelter, A. C., LLNL
Object Type: Article
System: The UNT Digital Library
Applications of MEMS-based biochemical analytical instrumentation (open access)

Applications of MEMS-based biochemical analytical instrumentation

The MicroTechnology Center at Lawrence Livermore National Laboratory is developing a variety of MEMS-Based analytical instrumentation systems in support of programmatic needs, along with numerous external customers. Several of the applications of interest are in the area of biochemical identification and analysis. These applications range from DNA fragment analysis and collection in support of the Human Genome Project, to detection of viruses or biological warfare agents. Each of the applications of interest has focused in micro-machined MEMS technology for reduced cost, higher throughput, and faster results. Development of these analytical instrumentation systems will have long term benefits for the medical community as well. The following describes the technologies several specific applications.
Date: May 21, 1997
Creator: Morse, J. D., LLNL
Object Type: Article
System: The UNT Digital Library
Experimental Investigation of the Classical Rayleigh-Taylor Instability (open access)

Experimental Investigation of the Classical Rayleigh-Taylor Instability

The evolution of the Rayleigh-Taylor (RT) instability in a compressible medium has been investigated at an accelerating embedded interface and at the ablation front in a series of experiments on the Nova laser. The x-ray drive generated in a gold hohlraum ablatively accelerated a planar target consisting of a doped plastic pusher backed by a higher density titanium payload with perturbations placed at the plastic-Ti interface. The targets were diagnosed by face-on and side-on radiography. In previous work focusing on single mode perturbations, wavelengths as short as 10 m have been observed to grow strongly at the embedded interface. Here multimode perturbations consisting of either 2, 10 or 20 modes superposed in phase have been investigated.
Date: May 21, 1996
Creator: Budil, K. S.; Remington, B. A.; Peyser, T. A.; Mikaelian, K. O.; Rubenchik, A. M.; Berning, M. et al.
Object Type: Article
System: The UNT Digital Library
Environmental assessment for consolidation of certain materials and machines for nuclear criticality experiments and training (open access)

Environmental assessment for consolidation of certain materials and machines for nuclear criticality experiments and training

In support of its assigned missions and because of the importance of avoiding nuclear criticality accidents, DOE has adopted a policy to reduce identifiable nuclear criticality safety risks and to protect the public, workers, government property and essential operations from the effects of a criticality accident. In support of this policy, the Los Alamos Critical Experiments Facility (LACEF) at the Los Alamos National Laboratory (LANL) Technical Area (TA) 18, provides a program of general purpose critical experiments. This program, the only remaining one of its kind in the United States, seeks to maintain a sound basis of information for criticality control in those physical situations that DOE will encounter in handling and storing fissionable material in the future, and ensuring the presence of a community of individuals competent in practicing this control.
Date: May 21, 1996
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Questionnaire for sensitive positions (QSP) version 4.0 -- Users guide document (open access)

Questionnaire for sensitive positions (QSP) version 4.0 -- Users guide document

The US Government does background investigations and reinvestigations to establish that applicants are eligible for required security clearance. The QSP system is an automated Paradox application developed by Boeing in 1988 and used by DOE-RL for data collection, retention, and printing by facsimile of the Standard Form 86 containing a person`s data needed to conduct an investigation. In March 1991 the QSP form was revised by the Office of Personnel Management (OPM). The QSP system was modified and enhanced to QSP version 3.0 and released for use in 1992. Copies of QSP version 3.0 were provided to approximately 20 other sites when requested. In February 1995 the OPM approved the new Standard Form 86 ``Questionnaire for National Security Positions.`` The QSP system was modified and upgraded to QSP version 4.0 to agree with the revised form.
Date: May 21, 1996
Creator: Hausel, J. M.
Object Type: Report
System: The UNT Digital Library
Coil end design for the LHC dipole magnet (open access)

Coil end design for the LHC dipole magnet

This paper describes the design of the coil ends for the Large Hadron Collider dipole magnets of the CERN European Laboratory for Particle Physics in Switzerland. This alternative to existing European designs was provided by Fermi National Accelerator Laboratory by agreement between CERN and the United States. The superconducting cable paths are determined from both magnetic and mechanical considerations. The coil end parts used to shape and constrain the conductors in the coil ends are designed using the developable surface, grouped end approach. This method allows the analysis of strain energy within the conductor groups, and the optimization of mechanical factors during the design. Design intent and implementation are discussed. Inner and outer coil design challenges and end analysis are detailed.
Date: May 21, 1996
Creator: Brandt, J.S.
Object Type: Report
System: The UNT Digital Library
Electron-impact ionization of air molecules and its application to the abatement of volatile organic compounds (open access)

Electron-impact ionization of air molecules and its application to the abatement of volatile organic compounds

In this paper the authors present data on the non-thermal plasma processing of two representative VOCs: carbon tetrachloride and methanol. The investigation used a compact electron beam reactor, and two types of discharge reactors: a pulsed corona and a dielectric-barrier discharge. To the knowledge of the authors, this is the first comparison of the energy efficiency of electron beam, pulsed corona and dielectric-barrier discharge processing of these VOCs under identical gas conditions. For most electrical discharge reactors the analysis suggests that the attainable electron mean energy is rather limited and cannot be significantly enhanced by changing the electrode configuration or voltage waveform. The experimental data confirms that there is no significant difference in the performance of the pulsed corona and dielectric-barrier discharge reactors. The authors observe that electron beam processing is remarkably more energy efficiency than electrical discharge processing in decomposing either of these VOC molecules. During electron beam processing, the specific energy consumption is consistent with the energy required for the ionization of the background air molecules. For carbon tetrachloride, the dominant decomposition pathway is dissociative electron attachment. For methanol, the dominant decomposition pathway is dissociative charge exchange.
Date: May 21, 1995
Creator: Penetrante, B. M.; Hsiao, M. C.; Bardsley, J. N.; Merritt, B. T.; Vogtlin, G. E.; Wallman, P. H. et al.
Object Type: Article
System: The UNT Digital Library
Quality Assurance Plan for site electrical replacements at substation line item subproject: 69 KV Substation (open access)

Quality Assurance Plan for site electrical replacements at substation line item subproject: 69 KV Substation

The 69 KV Substation Project is based on the recognized need to provide a continuous, reliable source of power and to improve the firm capacity of the electrical service to all production facilities at Mound. The project consists of the following major element: 69 KV Substation: (1) Install a 69 KV Substation and associated equipment with two parallel 18 MVA transformers. (2) Install duct bank as required and provide 15 KV feeder cable from new substation to existing Substation 95 for connection to Mound`s existing primary distribution system. (3) Install duct bank for underground routing of the 15 KV feeder cable from Manhole 5C to the existing power house cable pit. (4) Reconfigure existing Dayton Power and Light Co. 15 KV switchgear in P Building. The purpose of this Quality Assurance Plan (QA Plan) is to assure that the objectives of the United States Department of Energy (D.O.E.) and EG&G Mound Applied Technologies, Miamisburg, Ohio (Mound) are met for this non-weapons project relative to health and safety, protection of the environment, reliability and continuity of operations, and documentation of quality efforts. This QA Plan identifies the activities and responsibilities which are necessary in the design, procurement, fabrication, installation, and start …
Date: May 21, 1991
Creator: Ohler, C.K.
Object Type: Report
System: The UNT Digital Library
Industrial ecology at Lawrence Livermore National Laboratory summary statement (open access)

Industrial ecology at Lawrence Livermore National Laboratory summary statement

This statement summarizes Lawrence Livermore National Laboratory`s committment to making important scientific, technological, and business contributions to global sustainability. The quest has many aspects, some socio-political or economic and some technological, and some in which the soft and hard sciences become indistinguishable, as in visionary national strategies, like Holland`s, and futuristic regional and city development plans, like those of Kagoshima and Chattanooga.
Date: May 21, 1996
Creator: Gilmartin, T. J.
Object Type: Article
System: The UNT Digital Library
MCNP model for the many KE-Basin radiation sources (open access)

MCNP model for the many KE-Basin radiation sources

This document presents a model for the location and strength of radiation sources in the accessible areas of KE-Basin which agrees well with data taken on a regular grid in September of 1996. This modelling work was requested to support dose rate reduction efforts in KE-Basin. Anticipated fuel removal activities require lower dose rates to minimize annual dose to workers. With this model, the effects of component cleanup or removal can be estimated in advance to evaluate their effectiveness. In addition, the sources contributing most to the radiation fields in a given location can be identified and dealt with.
Date: May 21, 1997
Creator: Rittmann, P. D.
Object Type: Report
System: The UNT Digital Library
ITP Filter Particulate Decontamination Measurement (open access)

ITP Filter Particulate Decontamination Measurement

A new test method was developed which showed the installed In- Tank Precipitation Filter Unit {number_sign}3 provided at least 40, 000 x decontamination of the precipitated potassium tetraphenylborate (KTPB) during the cold chemical runs.This filter is expected to meet the needed 40,000 x hot cesium decontamination requirements, assuming that the cesium precipitate, CsTPB, behaves the same as KTPB. The new method permits cold chemicals field testing of installed filters to quantify particulate decontamination and verify filter integrity before going hot. The method involves a 1000 x concentration of fine particulate KTPB in the filtrate to allow direct analysis by counting for naturally radioactive isotope K-40 using the underground SRTC gamma spectroscopy facility. The particulate concentration was accomplished by ultra filtration at Rhone-Poulenc, NJ, using a small cross-flow bench facility, followed by collection of all suspended solids on a small filter disc for K analysis.
Date: May 21, 1993
Creator: Dworjanyn, L.O.
Object Type: Report
System: The UNT Digital Library
ITP Filtrate Benzene Removal Alternatives (open access)

ITP Filtrate Benzene Removal Alternatives

Existing ITP filtrate hold tanks may provide sufficient capacity and residence time to strip dissolved benzene from the incoming filtrate using nitrogen sparging in the bottom of the old tanks. This is based on equilibrium supported by late Wash test data using aged washed slurry. Theoretical considerations indicate that benzene stripping will be more difficult from the ITP unwashed high salt filtrates due to reduced mass transfer. Therefore experimental sparging data is needed to quantify the theoretical effects.Foaming limits which dictate allowable sparging rate will also have to be established. Sparging in the hold tanks will require installation of sintered metal spargers, and possibly stirrers and foam monitoring/disengagement equipment. The most critical sparging needs are at the start of the precipitation/concentration cycle, when the filtrate flux rate is the highest,and at the end of wash cycle where Henry`s equilibrium constant falls off,requiring more gas to sparge the dissolved benzene. With adequate recycle (for proper distribution) or sparging in the old tanks, the 30 inch column could be used for the complete ITP process. A courser packing would reduce back pressure while enabling benzene stripping. The Late Wash Tests indicate adequate benzene stripping even at reduced gas flow. This will require …
Date: May 21, 1993
Creator: Dworjanyn, L.O.
Object Type: Report
System: The UNT Digital Library
Particulate hot gas stream cleanup technical issues. Quarterly report, January--March 1996 (open access)

Particulate hot gas stream cleanup technical issues. Quarterly report, January--March 1996

To identify which ash characteristics can lead to problems with filtration, the authors have assembled 235 ash samples from eleven facilities involved in METC`s HGCU program. They have analyzed many of these ashes with a variety of laboratory tests. Physical attributes of the particles that they have examined include size distribution, specific surface area, particle morphology, and bulk ash cohesivity and permeability. They have also performed a range of chemical analyses on these ashes, as well as characterizations of agglomerates of ash removed from filter vessels at Tidd and Karhula. They are in the process of assembling the data obtained in these studies into an interactive data base which will help the manufacturers and operators of high-temperature barrier filters tailor their designs and operations to the specific characteristics of the ashes they are collecting. In order to understand the thermal and mechanical behavior of the various types of ceramic materials used in hot gas filtration, they have been performing hoop and axial tensile tests, thermal expansion, compression, and creep evaluations of these materials at temperatures up to 1,800 F. Nondestructive testing methods they perform on filter specimens include density and ultrasonic velocity. To date they have evaluated various characteristics of …
Date: May 21, 1996
Creator: unknown
Object Type: Report
System: The UNT Digital Library
324 and 327 essential drawing list (open access)

324 and 327 essential drawing list

The purpose of this document is to publish a list of essential drawings for the 324 and 327 Facilities. The report consists of a list of engineering drawings, not the drawings themselves.
Date: May 21, 1998
Creator: Spencer, R. H.
Object Type: Report
System: The UNT Digital Library
Thermal response of a can handling unit (CHU) to a postulated plutonium hydride burn (open access)

Thermal response of a can handling unit (CHU) to a postulated plutonium hydride burn

A series of analyses were performed to support the design of the Can Handling Unit (CHU). The subject analyses focused on determining the time to repressurize a subatmospheric storage can containing plutonium metal versus the initial hole size and the transient thermal response to a postulated chemical reaction of 150 grams of plutonium hydride. Limiting the amount of gaseous reactants either by inerting the CHU or using a very small hole size for the initial opening appears to be a viable method of controlling the rate of the exothermic chemical reactions and system temperatures.
Date: May 21, 1998
Creator: Crea, B. A.
Object Type: Report
System: The UNT Digital Library
Nuclear incident monitor criticality alarm instrument for the Savannah River Site: Technical manual (open access)

Nuclear incident monitor criticality alarm instrument for the Savannah River Site: Technical manual

The Savannah River Site is a Department of Energy facility. The facility stores, processes, and works with fissionable material at a number of locations. Technical standards and US Department of Energy orders, require these locations to be monitored by criticality alarm systems under certain circumstances. The Savannah River Site calls such instruments Nuclear Incident Monitors or NIMs. The Sole purpose of the Nuclear Incident Monitor is to provide an immediate evacuation signal in the case of an accidental criticality in order to minimize personnel exposure to radiation. The new unit is the third generation Nuclear Incident Monitor at the Savannah River Site. The second generation unit was developed in 1979. It was designed to eliminate vacuum-tube circuits, and was the first solid state NIM at SRS. The major design objectives of the second generation NIM were to improve reliability and reduce maintenance costs. Ten prototype units have been built and tested. This report describes the design of the new NIM and the testing that took place to verify its acceptability.
Date: May 21, 1996
Creator: Jenkins, J. B.
Object Type: Report
System: The UNT Digital Library
Packaging development programs recommended for the U.S.Department of Energy (open access)

Packaging development programs recommended for the U.S.Department of Energy

U.S. Department of Energy facilities were visited to determine their specific packaging needs. Those individual site needs were analyzed to determine widespread packaging needs. Those packaging needs are: replacements for aging Type B packagings, plutonium packaging, overpacks for large containers, heavily shielded Type B packaging, large radioactive liquid packaging, standardized waste packaging, and packaging for explosives.
Date: May 21, 1996
Creator: Edwards, W. S.
Object Type: Article
System: The UNT Digital Library
Project LOTSWIFE meeting of May 18, 1959 (open access)

Project LOTSWIFE meeting of May 18, 1959

None
Date: May 21, 1959
Creator: Denton, V.
Object Type: Report
System: The UNT Digital Library
Rossi-{alpha} measurements in the fast critical assembly XIX-2 (open access)

Rossi-{alpha} measurements in the fast critical assembly XIX-2

A Rossi-{alpha} experiment was performed on the zero-power, XIX-2 assembly at the Fast Critical Assembly (FCA) facility operated by the Japan Atomic Energy Research Institute (JAERI), Tokai-mura, Japan. The XIX-2 assembly is a plutonium/natural uranium system comprised of plutonium/natural uranium core surrounded by a depleted uranium dioxide blanket (referred to as the soft blanket). The soft blanket is surrounded by an outer blanket comprised of depleted uranium dioxide blanket (referred to as the depleted blanket). Because the neutron lifetime in the soft and depleted blankets are significantly larger than the neutron lifetime in the core region, multiple decay modes were observed during this experiment. The first decay mode was measured with reasonable accuracy; however, because of the high intrinsic source strength produced by the large amounts of Pu-240 contained in the core region, the intrinsic source background was reached very rapidly, thus precluding the second decay mode from being resolved well enough to estimate the average system lifetime. Nevertheless, using the first decay mode (i.e., the rapid die-away time constant), the alpha at delayed critical for this root was measured to be 13,100 +/- 134 s{sup -1}. This root is associated with the prompt neutron lifetime of the core region. …
Date: May 21, 1997
Creator: Spriggs, G.D.; Sakurai, Takeshi & Okajima, Shigeaki
Object Type: Article
System: The UNT Digital Library
Parallel computation of electromagnetic fields (open access)

Parallel computation of electromagnetic fields

The DSI3D code is designed to numerically solve electromagnetics problems involving complex objects by solving Maxwell`s curl equations in the time-domain and in three space dimensions. The code has been designed to run on the new parallel processing computers as well as on conventional serial computers. The DSI3D code is unique for the following reasons: It runs efficiently on a variety of parallel computers, Allows the use of unstructured non-orthogonal grids, Allows a variety of cell or element types, Reduces to be the Finite Difference Time Domain (FDID) method when orthogonal grids are used, Preserves charge or divergence locally (and globally), Is non- dissipative, and Is accurate for non-orthogonal grids. This method is derived using a Discrete Surface Integration (DSI) technique. As formulated, the DSI technique can be used with essentially arbitrary unstructured grids composed of convex polyhedral cells. This implementation of the DSI algorithm allows the use of unstructured grids that are composed of combinations of non-orthogonal hexahedrons, tetrahedrons, triangular prisms and pyramids. This algorithm reduces to the conventional FDTD method when applied on a structured orthogonal hexahedral grid.
Date: May 21, 1997
Creator: Madsen, N. K.
Object Type: Report
System: The UNT Digital Library
NEPA and NHPA- successful decommissioning of historic Manhattan Project properties at Los Alamos National Laboratory, Los Alamos, New Mexico (open access)

NEPA and NHPA- successful decommissioning of historic Manhattan Project properties at Los Alamos National Laboratory, Los Alamos, New Mexico

This paper describes experiences at Los Alamos National Laboratory during the process of planning and executing decommissioning and decontamination activities on a number of properties constructed as part of the Manhattan project. Many of these buildings had been abandoned for many years and were in deteriorating condition, in addition to being contaminated with asbestos, lead based paints and high explosive residues. Due to the age and use of the structures they were evaluated against criteria for the National Register of Historic Places. This process is briefly reviewed, along with the results, as well as actions implemented as a result of the condition and safety of the structures. A number of the structures have been decontaminated and demolished. Planning is still ongoing for the renovation of one structure, and the photographic and drawing records of the properties is near completion.
Date: May 21, 1997
Creator: McGehee, E.D. & Pendergrass, A.K.
Object Type: Article
System: The UNT Digital Library