Data and methods for the assessment of the risks associated with the maritime transport of radioactive materials: Results of the SeaRAM program studies. Volume 1 -- Main report (open access)

Data and methods for the assessment of the risks associated with the maritime transport of radioactive materials: Results of the SeaRAM program studies. Volume 1 -- Main report

This report describes ship accident event trees, ship collision and ship fire frequencies, representative ships and shipping practices, a model of ship penetration depths during ship collisions, a ship fire spread model, cask to environment release fractions during ship collisions and fires, and illustrative consequence calculations.
Date: May 1, 1998
Creator: Sprung, J. L.; Bespalko, S. J. & Kanipe, F. L.
Object Type: Report
System: The UNT Digital Library
Data and methods for the assessment of the risks associated with the maritime transport of radioactive materials: Results of the SeaRAM program studies. Volume 2 -- Appendices (open access)

Data and methods for the assessment of the risks associated with the maritime transport of radioactive materials: Results of the SeaRAM program studies. Volume 2 -- Appendices

This report describes ship accident event trees, ship collision and ship fire frequencies, representative ships and shipping practices, a model of ship penetration depths during ship collisions, a ship fire spread model, cask to environment release fractions during ship collisions and fires, and illustrative consequence calculations. This report contains the following appendices: Appendix 1 -- Representative Ships and Shipping Practices; Appendix 2 -- Input Data for Minorsky Calculations; Appendix 3 -- Port Ship Speed Distribution; and Appendix 4 -- Cask-to-Environment Release Fractions.
Date: May 1, 1998
Creator: Sprung, J. L.; Bespalko, S. J. & Kanipe, F. L.
Object Type: Report
System: The UNT Digital Library
Deep high-aspect ratio Si etching for advanced packaging technologies (open access)

Deep high-aspect ratio Si etching for advanced packaging technologies

Deep high-aspect ratio Si etching (HARSE) has shown potential application for passive self-alignment of dissimilar materials and devices on Si carriers or waferboards. The Si can be etched to specific depths and; lateral dimensions to accurately place or locate discrete components (i.e lasers, photodetectors, and fiber optics) on a Si carrier. It is critical to develop processes which maintain the dimensions of the mask, yield highly anisotropic profiles for deep features, and maintain the anisotropy at the base of the etched feature. In this paper the authors report process conditions for HARSE which yield etch rates exceeding 3 {micro}m/min and well controlled, highly anisotropic etch profiles. Examples for potential application to advanced packaging technologies will also be shown.
Date: May 1, 1998
Creator: Shul, R.J.; Willison, C.G.; Sullivan, C.T.; Kravitz, S.H.; Zhang, L. & Zipperian, T.E.
Object Type: Report
System: The UNT Digital Library
The Defense Waste Processing Facility: Two Years of Radioactive Operation (open access)

The Defense Waste Processing Facility: Two Years of Radioactive Operation

The Defense Waste Processing Facility (DWPF) at the Savannah River Site in Aiken, SC is currently immobilizing high level radioactive sludge waste in borosilicate glass. The DWPF began vitrification of radioactive waste in May, 1996. Prior to that time, an extensive startup test program was completed with simulated waste. The DWPF is a first of its kind facility. The experience gained and data collected during the startup program and early years of operation can provide valuable information to other similar facilities. This experience involves many areas such as process enhancements, analytical improvements, glass pouring issues, and documentation/data collection and tracking. A summary of this experience and the results of the first two years of operation will be presented.
Date: May 1, 1998
Creator: Marra, S.L.; Gee, J.T. & Sproull, J.F.
Object Type: Article
System: The UNT Digital Library
Deliverability on the interstate natural gas pipeline system (open access)

Deliverability on the interstate natural gas pipeline system

Deliverability on the Interstate Natural Gas Pipeline System examines the capability of the national pipeline grid to transport natural gas to various US markets. The report quantifies the capacity levels and utilization rates of major interstate pipeline companies in 1996 and the changes since 1990, as well as changes in markets and end-use consumption patterns. It also discusses the effects of proposed capacity expansions on capacity levels. The report consists of five chapters, several appendices, and a glossary. Chapter 1 discusses some of the operational and regulatory features of the US interstate pipeline system and how they affect overall system design, system utilization, and capacity expansions. Chapter 2 looks at how the exploration, development, and production of natural gas within North America is linked to the national pipeline grid. Chapter 3 examines the capability of the interstate natural gas pipeline network to link production areas to market areas, on the basis of capacity and usage levels along 10 corridors. The chapter also examines capacity expansions that have occurred since 1990 along each corridor and the potential impact of proposed new capacity. Chapter 4 discusses the last step in the transportation chain, that is, deliverability to the ultimate end user. Flow …
Date: May 1, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Density equalizing map projections (cartograms) in public health applications (open access)

Density equalizing map projections (cartograms) in public health applications

In studying geographic disease distributions, one normally compares rates among arbitrarily defined geographic subareas (e.g. census tracts), thereby sacrificing some of the geographic detail of the original data. The sparser the data, the larger the subareas must be in order to calculate stable rates. This dilemma is avoided with the technique of Density Equalizing Map Projections (DEMP){copyright}. Boundaries of geographic subregions are adjusted to equalize population density over the entire study area. Case locations plotted on the transformed map should have a uniform distribution if the underlying disease risk is constant. On the transformed map, the statistical analysis of the observed distribution is greatly simplified. Even for sparse distributions, the statistical significance of a supposed disease cluster can be calculated with validity. The DEMP algorithm was applied to a data set previously analyzed with conventional techniques; namely, 401 childhood cancer cases in four counties of California. The distribution of cases on the transformed map was analyzed visually and statistically. To check the validity of the method, the identical analysis was performed on 401 artificial cases randomly generated under the assumption of uniform risk. No statistically significant evidence for geographic non-uniformity of rates was found, in agreement with the original analysis …
Date: May 1, 1998
Creator: Merrill, D.W.
Object Type: Report
System: The UNT Digital Library
Deposition of lithium on a plasma edge probe in TFTR -- Behavior of lithium-painted walls interacting with edge plasmas (open access)

Deposition of lithium on a plasma edge probe in TFTR -- Behavior of lithium-painted walls interacting with edge plasmas

Recent observations have indicated that lithium pellet injection wall conditioning plays an important role in achieving the enhanced supershot regime in TFTR. However, little is understood about the behavior of lithium-coated limiter walls, interacting with edge plasmas. In the final campaign of TFTR, a cylindrical carbon fiber composite probe was inserted into the boundary plasma region and exposed to ohmically-heated deuterium discharges with lithium pellet injection. The ion-drift side probe surface exhibits a sign of codeposition of lithium, carbon, oxygen, and deuterium, whereas the electron side essentially indicates high-temperature erosion. It is found that lithium is incorporated in these codeposits in the form of oxide at the concentration of a few percent. In the electron side, lithium has been found to penetrate deeply into the probe material, presumably via rapid diffusion through interplane spaces in the graphite crystalline. Though it is not conclusive, materials mixing in the carbon and lithium system appears to be a key process in successful lithium wall conditioning.
Date: May 1, 1998
Creator: Hirooka, Y.; Ashida, K. & Kugel, H.
Object Type: Article
System: The UNT Digital Library
Design and characterization of microscale heater structures for test die and sensor applications (open access)

Design and characterization of microscale heater structures for test die and sensor applications

The authors describe a class of microscale heaters fabricated with CMOS processes on silicon wafers. These heaters were designed to produce localized high temperatures above 400 C for test and sensor applications. The temperature levels produced for various input powers and the thermal profiles surrounding the heater for packaged and wafer-level heater structures were studied to guide the placement of microelectronics integrated with the heater structures on the same die. To show the performance of the design, they present resistance sensor measurements, IR temperature profiles, and results from a 3D thermal model of the die. This effort demonstrates that it is possible to successfully operate both a microscale heater and microcircuits on the same die.
Date: May 1, 1998
Creator: Benson, D. A.; Bowman, D.; Filter, W.; Mitchell, R. & Perry, J.
Object Type: Article
System: The UNT Digital Library
Design and experimental results on a terawatt magnetically controlled plasma opening switch (open access)

Design and experimental results on a terawatt magnetically controlled plasma opening switch

The magnetically controlled plasma opening switch (MCPOS) is an advanced plasma opening switch that utilizes magnetic fields to improve operation. Magnetic fields always dominate terawatt, pulsed power plasma opening switches. For that reason, the MCPOS uses controlled applied magnetic fields with magnitude comparable to the self-magnetic field of the storage inductor. One applied field holds the plasma in place while energy accumulates in the storage inductor, then another applied field pushes the plasma away from the cathode to allow energy to flow downstream. Over a ten month period, an MCPOS was designed, built, and tested on DECADE Module 2 at Physics International. The peak drive current was 1.8 MA in 250 ns. The output parameters were up to 1 MA into an electron beam load. The radiation temporal pulse width averaged 60 nanoseconds full-width at half-maximum. The peak load voltage ranged from one to two megavolts. The experiments demonstrated efficient power flow through a long, low-impedance magnetically insulated transmission line between the magnetically controlled plasma opening switch and the load.
Date: May 1, 1998
Creator: Savage, M. E.; Simpson, W. W.; Mendel Jr., C. W.; McDaniel, D. H.; Levine, J. S. & Tucker, T. S.
Object Type: Report
System: The UNT Digital Library
Design for environment for the National Ignition Facility (open access)

Design for environment for the National Ignition Facility

The National Ignition Facility (NIF) will be a U.S. Department of Energy (DOE) national center for inertial confinement fusion (ICF) and other research into the physics of high temperatures and high densities, and a vital element of the DOE`s nuclear weapons Stockpile Stewardship and Management Program. It will be used by scientists from a numerous different institutions and disciplines to support research advancements in national security, energy, basic science, and economic development. Multiple powerful laser beams will `ignite` small fusion targets, helping liberate more energy than is required to initiate the fusion reactions. This paper discusses the Design for Environment process for NIF, some of the subsequent activities resulting from the initial study, and a few of the lessons learned from this process. Subsequent activities include the development of a Pollution Prevention and Waste Minimization Plan (P2/WMin) for the facility, which includes Pollution Prevention Opportunity Assessments (PPOAS) on predicted waste streams from NIF, development of construction phase recycling plans, analysis of some of the specialized materials of construction to minimize future demolition and decommissioning (D&D) costs and development of cost assessments for more benign cleaning procedures that meet the stringent cleaning specifications for this facility.
Date: May 1, 1998
Creator: Cantwell, E.; Gobor, K.; Celeste, J. & Cerruti, S.
Object Type: Article
System: The UNT Digital Library
Design of a californium source-driven measurement system for accountability of material recovered from the Molten Salt Reactor Experiment charcoal bed (open access)

Design of a californium source-driven measurement system for accountability of material recovered from the Molten Salt Reactor Experiment charcoal bed

The Molten Salt Reactor Experiment Facility (MSRE) operated from 1965 to 1969. The fuel was a molten salt that flowed through the reactor core which consisted of uranium tetrafluoride with molten lithium and beryllium salt used as the coolant. In 1968 the fuel was switched from {sup 235}U to {sup 233}U. The Molten Salt Reactor Experiment was canceled in 1969 at which time approximately 4800 kg of salt was transferred to the fuel drain tanks. There was about 36.3 kg of uranium, 675 grams of plutonium and various fission products present in the fuel salt. The salt was allowed to solidify in the fuel drain tanks. The salt was heated on a yearly basis to recombine the fluorine gas with the uranium salt mixture. In March 1994, a gas sample was taken from the off gas system that indicated {sup 233}U had migrated from the fuel drain tank system to the off gas system. It was found that approximately 2.6 kg of uranium had migrated to the Auxiliary Charcoal Bed (ACB). The ACB is located in the concrete-lined charcoal bed cell which is below ground level located outside the MSRE building. Therefore, there was a concern for the potential of …
Date: May 1, 1998
Creator: Bentzinger, D.L.; Perez, R.B.; Mattingly, J.K.; Valentine, T.E. & Mihalczo, J.T.
Object Type: Article
System: The UNT Digital Library
Design Study of a Visible/Infrared Periscope for Intense Radiation Applications using Reflective Optics (open access)

Design Study of a Visible/Infrared Periscope for Intense Radiation Applications using Reflective Optics

In magnetically confined fusion devices employing deuterium-tritium (D-T) operation, refractive optical components exposed to neutron and gamma radiation can be subject to degradation of the transmission characteristics, induced luminescence, and altered mechanical properties including dimensional changes. Although radiation resistant refractive optics functioned well for the Tokamak Fusion Test Reactor (TFTR) periscope system during D-T operation, this design approach is unpromising in the much more hostile radiation environment of future D-T devices such as the International Thermonumclear Experimental Reactor (ITER). Under contract to the Princeton Plasma Physics Laboratory, Ball Aerospace of Colorado carried out a periscope design study based on the use of reflective optics. In this design, beryllium reflective input optics supported by a fused silica optical bench were interfaced to a Cassegrain relay system to transfer plasma images to remotely located cameras. This system is also capable of measuring first-wall surface temperatures in the range of 300 - 2,000 degrees C even under projected heating of the reflective optics themselves to several hundred degrees Celsius. Tests of beryllium mirror samples, however, revealed that operation at temperatures above 700 degrees C leads to a loss of specular reflectivity, thus placing an upper limit on the acceptable thermal environment. The main …
Date: May 1, 1998
Creator: Medley, S. S.
Object Type: Article
System: The UNT Digital Library
Design tools and issues of silicon micromachined (MEMS) devices (open access)

Design tools and issues of silicon micromachined (MEMS) devices

This paper describes the design and design issues associated with silicon surface micromachined device design Some of the tools described are adaptations of macro analysis tools. Design issues in the microdomain differ greatly from design issues encountered in the macrodomain. Microdomain forces caused by electrostatic attraction, surface tension, Van der Walls forces, and others can be more significant than inertia, friction, or gravity. Design and analysis tools developed for macrodomain devices are inadequate in most cases for microdomain devices. Microdomain specific design and analysis tools are being developed, but are still immature and lack adequate functionality. The fundamental design process for surface micromachined devices is significantly different than the design process employed in the design of macro-sized devices. In this paper, MEMS design will be discussed as well as the tools used to develop the designs and the issues relating fabrication processes to design. Design and analysis of MEMS devices is directly coupled to the silicon micromachining processes used to fabricate the devices. These processes introduce significant design limitations and must be well understood before designs can be successfully developed. In addition, some silicon micromachining fabrication processes facilitate the integration of silicon micromachines with microelectronics on-chip. For devices requiring on-chip …
Date: May 1, 1998
Creator: Davies, B. R.; Rodgers, M. S. & Montague, S.
Object Type: Article
System: The UNT Digital Library
Designing microelectromechanical systems-on-a-chip in a 5-level surface micromachine technology (open access)

Designing microelectromechanical systems-on-a-chip in a 5-level surface micromachine technology

A new 5-level polysilicon surface micromachine process has been developed that offers significantly increased system complexity, while further promoting the manufacturability and reliability of microscopic mechanical systems. In general, as complexity increases, reliability suffers. This is not necessarily the case, however, with MicroElectroMechanical Systems (MEMS). In fact, utilizing additional levels of polysilicon in structures can greatly increase yield, reliability, and robustness. Surface micromachine devices are built thousands at a time using the infrastructure developed to support the incredibly reliable microelectronics industry, and the batch fabrication process utilized in the 5-level technology further increases reliability and reduces cost by totally eliminating post assembly.
Date: May 1, 1998
Creator: Rodgers, M.S. & Sniegowski, J.J.
Object Type: Article
System: The UNT Digital Library
Detached divertor operation in DIII-D helium plasmas (open access)

Detached divertor operation in DIII-D helium plasmas

This paper presents results from operating helium plasmas in DIII-D in which helium gas puffing is used to reduce the peak divertor heat flux by factors of four or more. The threshold density for achieving these conditions is nearly the same as for deuterium plasmas, which is surprising given the fact that lack of chemical sputtering reduces the carbon concentration in the plasma by more than a factor of five. Spectroscopic analysis shows that helium becomes the primary radiation in these plasmas, which is possible because, unlike carbon, it is the primary species present. These plasmas differ from the usual partially detached divertor (PDD) plasmas in that there is no concomitant reduction in target plate ion flux with target plate heat flux in the scrape off later outside the separatrix.
Date: May 1, 1998
Creator: Hill, D. N., LLNL
Object Type: Article
System: The UNT Digital Library
Determination of silica scale deposition rates and thresholds applied toward protection of injection reservoirs. Quarterly progress report, January 1, 1988--March 31, 1998 (open access)

Determination of silica scale deposition rates and thresholds applied toward protection of injection reservoirs. Quarterly progress report, January 1, 1988--March 31, 1998

The program objective aims to identify the highest temperature at which silica scale will develop from partially evaporated and significantly cooled geothermal liquid. The approach involves tracking deposition of silica scale by monitoring the apparent electrical conductivity of the geothermal liquid in an isolation chamber. A decrease in apparent conductivity occurs because the deposited silica is less conductive than the geothermal liquid. The major technical hurdle is building a conductivity monitoring system that is sensitive enough to distinguish between no silica deposition and almost no silica deposition, while accounting for other factors which also affect conductivity, such as temperature and varying fluid composition.
Date: May 1, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
A deterministic method for transient, three-dimensional neutron transport (open access)

A deterministic method for transient, three-dimensional neutron transport

A deterministic method for solving the time-dependent, three-dimensional Boltzmann transport equation with explicit representation of delayed neutrons has been developed and evaluated. The methodology used in this study for the time variable of the neutron flux is known as the improved quasi-static (IQS) method. The position, energy, and angle-dependent neutron flux is computed deterministically by using the three-dimensional discrete ordinates code TORT. This paper briefly describes the methodology and selected results. The code developed at the University of Tennessee based on this methodology is called TDTORT. TDTORT can be used to model transients involving voided and/or strongly absorbing regions that require transport theory for accuracy. This code can also be used to model either small high-leakage systems, such as space reactors, or asymmetric control rod movements. TDTORT can model step, ramp, step followed by another step, and step followed by ramp type perturbations. It can also model columnwise rod movement. A special case of columnwise rod movement in a three-dimensional model of a boiling water reactor (BWR) with simple adiabatic feedback is also included. TDTORT is verified through several transient one-dimensional, two-dimensional, and three-dimensional benchmark problems. The results show that the transport methodology and corresponding code developed in this work …
Date: May 1, 1998
Creator: Goluoglu, S.; Bentley, C.; DeMeglio, R.; Dunn, M.; Norton, K.; Pevey, R. et al.
Object Type: Article
System: The UNT Digital Library
Development and validation of nondestructive inspection techniques for composite doubler repairs on commercial aircraft (open access)

Development and validation of nondestructive inspection techniques for composite doubler repairs on commercial aircraft

Composite doublers, or repair patches, provide an innovative repair technique which can enhance the way aircraft are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is possible to bond a single boron-epoxy composite doubler to the damaged structure. In order for the use of composite doublers to achieve widespread use in the civil aviation industry, it is imperative that methods be developed which can quickly and reliably assess the integrity of the doubler. In this study, a specific composite application was chosen on an L-1011 aircraft in order to focus the tasks on application and operation issues. Primary among inspection requirements for these doublers is the identification of disbonds, between the composite laminate and aluminum parent material, and delaminations in the composite laminate. Surveillance of cracks or corrosion in the parent aluminum material beneath the doubler is also a concern. No single nondestructive inspection (NDI) method can inspect for every flaw type, therefore it is important to be aware of available NDI techniques and to properly address their capabilities and limitations. A series of NDI tests were conducted on laboratory test structures and on full-scale aircraft fuselage sections. Specific challenges, unique to bonded …
Date: May 1, 1998
Creator: Roach, D. & Walkington, P.
Object Type: Report
System: The UNT Digital Library
Development of a bottom-hole gamma-ray diagnostic capability for high-level environments, during CTBT on-site inspection drilling (open access)

Development of a bottom-hole gamma-ray diagnostic capability for high-level environments, during CTBT on-site inspection drilling

The verification regime of the Comprehensive Test Ban Treaty (CTBT) provides for the possibility of on-site inspections (OSI`s) to resolve questions concerning suspicious events which may have been clandestine nuclear tests. The initial phase of an OSI may provide enough evidence to justify a request to the CTBT Organization for allowing drilling, so as to recover further evidence of a nuclear event. The equipment that was used for such `re-entry` drilling in the days of U.S. underground nuclear testing is considered too heavy and cumbersome for OSI deployments. So, an effort was initiated in 1995 to define, assemble, and demonstrate a new OSI drilling capability. Coiled-tubing (C-T) was selected as the most attractive technology because of its portability and its directional drilling capability (1). Following this selection, a preliminary engineering design was performed in 1996 for a Rapid Deployment Drilling System (RDDS). This system must have capabilities for downhole diagnostics of temperature and gamma-rays, since both types of data could be used to confirm the presence of an underground nuclear explosion. The study then identified two candidate downhole diagnostic systems operating with CT: the VIPER system of Schlumberger-Anadrill, and the Transocean system (2). In the current phase of this continuing …
Date: May 1, 1998
Creator: Fontenot, Robert & Fontenot, R., Schlumberger-Anadrill, Sugarland, TX, LLNL
Object Type: Report
System: The UNT Digital Library
The Development of Chemically Vapor Deposited Mullite Coatings for the Corrosion Protection of SiC (open access)

The Development of Chemically Vapor Deposited Mullite Coatings for the Corrosion Protection of SiC

Crystalline mullite coatings have been chemically vapor deposited onto SiC substrates to enhance the corrosion and oxidation resistance of the substrate. Current research has been divided into three distinct areas: (1) Development of the deposition processing conditions for increased control over coating`s growth rate, microstructure, and morphology; (2) Analysis of the coating`s crystal structure and stability; (3) The corrosion resistance of the CVD mullite coating on SiC.
Date: May 1, 1998
Creator: Auger, M.; Hou, P.; Sengupta, A.; Basu, S. & Sarin, V.
Object Type: Report
System: The UNT Digital Library
Development of dosimetric approaches to treatment planning for radioimmunotherapy. DOE annual report (open access)

Development of dosimetric approaches to treatment planning for radioimmunotherapy. DOE annual report

The objective of quantitative imaging is to Provide pharmacokinetic information for patients that is analogous to that provided by biodistribution studies in mice. Radio nuclide images depict the distribution of labeled antibodies in-vivo; thus the amount of radio nuclide in a specific organ or site can be estimated by relating the counts detected in a defined region of interest to the total radio nuclide content. This pharmacokinetic information can be used to obtain definitive and relevant answers to basic questions of importance for optimizing radioimmunoimaging and radioimmunotherapy and, in addition, can provide a data base from which to calculate the distribution of radiation absorbed doses. The projects supported by this program routinely employ quantitative imaging in evaluating therapies. Quantitative imaging is performed by a certified nuclear medicine technician using the Siemens gamma camera interfaced with the microVAX II. The technician processes the imaging data and obtains pharmacokinetic information from it using programs developed by us and others. During this grant period project staff have acquired and analyzed a large amount of data on the pharmacokinetics, dosimetry and toxicity of radiolabeled monoclonal therapy. Important dosimetry data on the whole body, marrow and tumor doses are available and all studies are archived …
Date: May 1, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Development of embrittlement prediction models for U.S. power reactors and the impact of the heat-affected zone to thermal annealing (open access)

Development of embrittlement prediction models for U.S. power reactors and the impact of the heat-affected zone to thermal annealing

The NRC Regulatory Guide 1.99 Revision 2 was based on 177 surveillance data points and the EPRI data base, where 76% of 177 data points and 60% of EPRI data base were from Westinghouse`s data. Therefore, other vendors` radiation environment may not be properly characterized by R.G. 1.99`s prediction. To minimize scatter from the influences of the irradiation temperature, neutron energy spectrum, displacement rate, and plant operation procedures on embrittlement models, improved embrittlement models based on group data that have similar radiation environments and reactor design and operation criteria are examined. A total of 653 shift data points from the current FR-EDB, including 397 Westinghouse data, 93 B and W data, 37 CE data, and 106 GE data, are used. A nonlinear least squares fitting FORTRAN program, incorporating a Monte Carlo procedure with 35% and 10% uncertainty assigned to the fluence and shift data, respectively, was written for this study. In order to have the same adjusted fluence value for the weld and plate material in the same capsule, the Monte Carlo least squares fitting procedure has the ability to adjust the fluence values while running the weld and plate formula simultaneously. Six chemical components, namely, copper, nickel, phosphorus, sulfur, …
Date: May 1, 1998
Creator: Wang, J. A.
Object Type: Article
System: The UNT Digital Library
Development of High Activity, Coal-Derived, Promoted Catalytic Systems for NOx Reduction at Low Temperatures (open access)

Development of High Activity, Coal-Derived, Promoted Catalytic Systems for NOx Reduction at Low Temperatures

This project is directed at an investigation of catalytic NO{sub x} reduction mechanisms on coal-derived, activated carbon supports at low temperatures. Promoted carbon systems offer some potentially significant advantages for heterogeneous NO{sub x} reduction. These include: low cost; high activity at low temperatures, which minimizes carbon loss; oxygen resistance; and a support material which can be engineered with respect to porosity, transport and catalyst dispersion characteristics.
Date: May 1, 1998
Creator: Calo, J. M.
Object Type: Report
System: The UNT Digital Library
Development of nuclear analysis capabilities for DOE waste management activities (open access)

Development of nuclear analysis capabilities for DOE waste management activities

The objective of this project is to develop and demonstrate prototypic analysis capabilities that can be used by the nuclear safety analysis practitioners to: (1) demonstrate a more thorough understanding of the underlying physics phenomena that can lead to improved reliability and defensibility of safety evaluations; and (2) optimize operations related to the handling, storage, transportation, and disposal of fissile material and DOE spent fuel. To address these problems, the project will investigate the implementation of sensitivity and uncertainty methods within existing Monte Carlo codes used for criticality safety analyses, as well as within a new deterministic code that allows specification of arbitrary grids to accurately model the geometry details required in a criticality safety analysis. This capability can facilitate improved estimations of the required subcritical margin and potentially enable the use of a broader range of experiments in the validation process. The new arbitrary-grid radiation transport code will also enable detailed geometric modeling valuable for improved accuracy in application to a myriad of other problems related to waste characterization. Application to these problems will also be explored.
Date: May 1, 1998
Creator: Parks, Cecil V.; DeHart, Mark D.; Broadhead, Bryan L.; Hopper, Calvin M. & Petrie, Lester M.
Object Type: Report
System: The UNT Digital Library