160 C PROTON EXCHANGE MEMBRANE (PEM) FUEL CELL SYSTEM DEVELOPMENT (open access)

160 C PROTON EXCHANGE MEMBRANE (PEM) FUEL CELL SYSTEM DEVELOPMENT

The objectives of this program were: (a) to develop and demonstrate a new polymer electrolyte membrane fuel cell (PEMFC) system that operates up to 160 C temperatures and at ambient pressures for stationary power applications, and (b) to determine if the GTI-molded composite graphite bipolar separator plate could provide long term operational stability at 160 C or higher. There are many reasons that fuel cell research has been receiving much attention. Fuel cells represent environmentally friendly and efficient sources of electrical power generation that could use a variety of fuel sources. The Gas Technology Institute (GTI), formerly Institute of Gas Technology (IGT), is focused on distributed energy stationary power generation systems. Currently the preferred method for hydrogen production for stationary power systems is conversion of natural gas, which has a vast distribution system in place. However, in the conversion of natural gas into a hydrogen-rich fuel, traces of carbon monoxide are produced. Carbon monoxide present in the fuel gas will in time cumulatively poison, or passivate the active platinum catalysts used in the anodes of PEMFC's operating at temperatures of 60 to 80 C. Various fuel processors have incorporated systems to reduce the carbon monoxide to levels below 10 ppm, …
Date: December 21, 2001
Creator: Marianowski, L. G.
Object Type: Report
System: The UNT Digital Library
Actinide-Aluminate Speciation in Alkaline Radioactive Waste (open access)

Actinide-Aluminate Speciation in Alkaline Radioactive Waste

Investigation of behavior of actinides in alkaline media containing AL(III) showed that no aluminate complexes of actinides in oxidation states (IIII-VIII) were formed in alkaline solutions. At alkaline precipitation IPH (10-14) of actinides in presence of AL(III) formation of aluminate compounds is not observed. However, in precipitates contained actinides (IIV)<(VI), and to a lesser degree actinides (III), some interference of components takes place that is reflected in change of solid phase properties in comparison with pure components or their mechanical mixture. The interference decreases with rise of precipitation PH and at PH 14 is exhibited very feebly. In the case of NP(VII) the individual compound with AL(III) is obtained, however it is not aluminate of neptunium(VII), but neptunate of aluminium(III) similar to neptunates of other metals obtained earlier.
Date: December 21, 2001
Creator: Clark, Dr. David L. & Fedosseev, Dr. Alexander M.
Object Type: Report
System: The UNT Digital Library
Adapting MARSSIM for FUSRAP site closure. (open access)

Adapting MARSSIM for FUSRAP site closure.

The Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) provides a coherent, technically defensible process for establishing that exposed surfaces satisfy site cleanup requirements. Unfortunately, many sites have complications that challenge a direct application of MARSSIM. Example complications include Record of Decision (ROD) requirements that are not MARSSIM-friendly, the potential for subsurface contamination, and incomplete characterization information. These types of complications are typically the rule, rather than the exception, for sites undergoing radiologically-driven remediation and closure. One such site is the Formerly Utilized Sites Remedial Action Program (FUSRAP) Linde site in Tonawanda, New York. Cleanup of the site is currently underway. The Linde site presented a number of challenges to designing and implementing a closure strategy consistent with MARSSIM. This paper discusses some of the closure issues confronted by the U.S. Army Corps of Engineers Buffalo District at the Linde site, and describes how MARSSIM protocols were adapted to address these issues.
Date: December 21, 2001
Creator: Johnson, R.; Durham, L.; Rieman, C. & Hoover, R.
Object Type: Article
System: The UNT Digital Library
Coarse-Grained Molecular Dynamics and Multiscale Modeling of NEMS Resonators (open access)

Coarse-Grained Molecular Dynamics and Multiscale Modeling of NEMS Resonators

We review concurrent multiscale simulations of dynamic and temperature-dependent processes found in nanomechanical systems coupled to larger scale surroundings. We focus on the behavior of sub-micron Micro-Electro-Mechanical Systems (MEMS), especially microresonators. These systems are often called NEMS, for Nano-Electro-Mechanical Systems. The coupling of length scales methodology we have developed for MEMS employs an atomistic description of small but key regions of the system, consisting of millions of atoms, coupled concurrently to a finite element model of the periphery. The model, Coarse-Grained Molecular Dynamics (CGMD), builds a generalized finite element formalism from the underlying atomistic physics in order to ensure a smooth coupling between regions governed by different length scales. The result is a model that accurately describes the behavior of the mechanical components of MEMS down to the atomic scale.
Date: December 21, 2001
Creator: Rudd, R E
Object Type: Article
System: The UNT Digital Library
Coarse-Grained Molecular Dynamics: Dissipation Due to Internal Modes (open access)

Coarse-Grained Molecular Dynamics: Dissipation Due to Internal Modes

We describe progress on the issue of pathological elastic wave reflection in atomistic and multiscale simulation. First we briefly review Coarse-Grained Molecular Dynamics (CGMD). Originally CGMD was formulated as a Hamiltonian system in which energy is conserved. This formulation is useful for many applications, but recently CGMD has been extended to include generalized Langevin forces. Here we describe how Langevin dynamics arise naturally in CGMD, and we examine the implication for elastic wave scattering.
Date: December 21, 2001
Creator: Rudd, R E
Object Type: Article
System: The UNT Digital Library
Compact Fluorescent Plug-In Ballast-in-a-Socket (open access)

Compact Fluorescent Plug-In Ballast-in-a-Socket

The primary goal of this program was to develop a ballast system for plug-in CFLs (compact fluorescent lamps) that will directly replace standard metal shell, medium base incandescent lampholders (such as Levition No. 6098) for use with portable lamp fixtures, such as floor, table and desk lamps. A secondary goal was to identify a plug-in CFL that is optimized for use with this ballast. This Plug-in CFL Ballastin-a-Socket system will allow fixture manufacturers to easily manufacture CFL-based high-efficacy portable fixtures that provide residential and commercial consumers with attractive, cost-effective, and energy-efficient fixtures for use wherever portable incandescent fixtures are used today. The advantages of this proposed system over existing CFL solutions are that the fixtures can only be used with high-efficacy CFLs, and they will be more attractive and will have lower life-cycle costs than screw-in or adapter-based CFL retrofit solutions. These features should greatly increase the penetration of CFL's into the North American market. Our work has shown that using integrated circuits it is quite feasible to produce a lamp-fixture ballast of a size comparable to the current Edison-screw 3-way incandescent fixtures. As for price points for BIAS-based fixtures, end-users polled by the Lighting Research Institute at RPI indicated …
Date: December 21, 2001
Creator: Voelker, Rebecca
Object Type: Report
System: The UNT Digital Library
Correlation of Chemisorption and Electronic Effects for Metal Oxide Interfaces: Transducing Principles for Temperature Programmed Gas Microsensors (Final Report) (open access)

Correlation of Chemisorption and Electronic Effects for Metal Oxide Interfaces: Transducing Principles for Temperature Programmed Gas Microsensors (Final Report)

This Final Report describes efforts and results for a 3-year DoE/OST-EMSP project centered at NIST. The multidisciplinary project investigated scientific and technical concepts critical for developing tunable, MEMS-based, gas and vapor microsensors that could be applied for monitoring the types of multiple analytes (and differing backgrounds) encountered at DoE waste sites. Micromachined ''microhotplate'' arrays were used as platforms for fabricating conductometric sensor prototypes, and as microscale research tools. Efficient microarray techniques were developed for locally depositing and then performance evaluating thin oxide films, in order to correlate gas sensing characteristics with properties including composition, microstructure, thickness and surface modification. This approach produced temperature-dependent databases on the sensitivities of sensing materials to varied analytes (in air) which enable application-specific tuning of microsensor arrays. Mechanistic studies on adsorb ate transient phenomena were conducted to better understand the ways in which rapid temperature programming schedules can be used to produce unique response signatures and increase information density in microsensor signals. Chemometric and neural network analyses were also employed in our studies for recognition and quantification of target analytes.
Date: December 21, 2001
Creator: Semancik, S.; Cavicchi, R. E.; DeVoe, D. L. & McAvoy, T. J.
Object Type: Report
System: The UNT Digital Library
Effects of composition and exposure on the solar reflectance of Portland cement concrete (open access)

Effects of composition and exposure on the solar reflectance of Portland cement concrete

Increasing the solar reflectance (albedo) of a paved surface keeps it cooler in the sun, reducing convection of heat from pavement to air and thereby decreasing the ambient air temperature. Simulations of the influence of pavement albedo on air temperature in Los Angeles predict that increasing the albedo of 1,250 km2 of pavement by 0.25 would save cooling energy worth $15M yr-1, and reduce smog-related medical and lost-work expenses by $76M yr-1. Most sidewalks and a small fraction of roads and parking areas are paved with portland cement concrete, which can be made quite reflective through suitable choice of cement and aggregate. Variations with composition and environmental exposure of the albedos of portland cement concrete pavements were investigated through laboratory fabrication and exposure of 32 mixes of concrete. Twenty-four mixes yielded substandard, ''rough'' concretes due to high, unmet aggregate water demand. The albedos of the remaining eight ''smooth'' concrete mixes ranged from 0.41 to 0.77 (mean 0.59). Simulated weathering, soiling, and abrasion each reduced average concrete albedo (mean decreases 0.06, 0.05, and 0.19, respectively), though some samples became slightly more reflective through weathering or soiling. Simulated rain (wetting) strongly depressed the albedos of concretes (mean decrease 0.23) until their surfaces …
Date: December 21, 2001
Creator: Levinson, Ronnen & Akbari, Hashem
Object Type: Report
System: The UNT Digital Library
Enhancements to modeling regional climate response and global variability (open access)

Enhancements to modeling regional climate response and global variability

Efforts during this grant period focused on three main considerations: (a) developing and testing various climate scenarios with SEAM, a newly created model (b) model reconstruction efforts to speed up computations and (c) optimum realization statistics
Date: December 21, 2001
Creator: Baer, Ferdinand; Tribbia, Joseph J. & Taylor, Mark
Object Type: Report
System: The UNT Digital Library
Horizontal gene transfer as adaptive response to heavy metal stress in subsurface microbial communities. Final report for period October 15, 1997 - October 15, 2000 (open access)

Horizontal gene transfer as adaptive response to heavy metal stress in subsurface microbial communities. Final report for period October 15, 1997 - October 15, 2000

Horizontal gene transfer as adaptive response to heavy metal stress in the presence of heavy metal stress was evaluated in oligotrophic subsurface soil laboratory scale microcosms. Increasing levels of cadmium (10, 100 and 1000 mM) were applied and an E. coli donor was used to deliver the target plasmids, pMOL187 and pMOL222, which contained the czc and ncc operons, and the helper plasmid RP4. Plasmid transfer was evaluated through monitoring of the heavy metal resistance and presence of the genes. The interactive, clearly revealed, effect of biological and chemical external factors on the extent of plasmid-DNA propagation in microbial communities in contaminated soil environments was observed in this study. Additionally, P.putida LBJ 415 carrying a suicide construct was used to evaluate selective elimination of a plasmid donor.
Date: December 21, 2001
Creator: Smets, B. F.
Object Type: Report
System: The UNT Digital Library
Initiation, Growth and Mitigation of UV Laser Induced Damage in Fused Silica (open access)

Initiation, Growth and Mitigation of UV Laser Induced Damage in Fused Silica

Laser damage of large fused silica optics initiates at imperfections. Possible initiation mechanisms are considered. We demonstrate that a model based on nanoparticle explosions is consistent with the observed initiation craters. Possible mechanisms for growth upon subsequent laser irradiation, including material modification and laser intensification, are discussed. Large aperture experiments indicate an exponential increase in damage size with number of laser shots. Physical processes associated with this growth and a qualitative explanation of self-accelerated growth is presented. Rapid growth necessitates damage growth mitigation techniques. Several possible mitigation techniques are mentioned, with special emphasis on CO{sub 2} processing. Analysis of material evaporation, crack healing, and thermally induced stress are presented.
Date: December 21, 2001
Creator: Rubenchik, A M & Feit, M D
Object Type: Article
System: The UNT Digital Library
Isotopically controlled semiconductors (open access)

Isotopically controlled semiconductors

Semiconductor bulk crystals and multilayer structures with controlled isotopic composition have attracted much scientific and technical interest in the past few years. Isotopic composition affects a large number of physical properties, including phonon energies and lifetimes, bandgaps, the thermal conductivity and expansion coefficient and spin-related effects. Isotope superlattices are ideal media for self-diffusion studies. In combination with neutron transmutation doping, isotope control offers a novel approach to metal-insulator transition studies. Spintronics, quantum computing and nanoparticle science are emerging fields using isotope control.
Date: December 21, 2001
Creator: Haller, Eugene E.
Object Type: Article
System: The UNT Digital Library
Modeling of the Deformation of Living Cells Induced by Atomic Force Microscopy (open access)

Modeling of the Deformation of Living Cells Induced by Atomic Force Microscopy

We describe finite element modeling of the deformation of living cells by atomic force microscopy (AFM). Cells are soft systems, susceptible to large deformations in the course of an AFM measurement. Often the local properties, the subject of the measurement, are obscured by the response of the cell as a whole. The Lagrangian finite deformation model we have developed and implemented in finite elements analysis offers a solution to this problem. The effect of the gross deformation of the cell can be subtracted from the experimentally measured data in order to give a reproducible value for local properties. This facilitates concurrent experimental efforts to measure the mechanical properties at specific receptor sites on the membrane of a living cell.
Date: December 21, 2001
Creator: Rudd, Robert E.; McElfresh, Michael; Baesu, Eveline; Balhorn, Rod; Allen, Michael J. & Belak, James
Object Type: Article
System: The UNT Digital Library
MULTISCALE THERMOHYDROLOGIC MODEL (open access)

MULTISCALE THERMOHYDROLOGIC MODEL

The purpose of the Multiscale Thermohydrologic Model (MSTHM) is to describe the thermohydrologic evolution of the near-field environment (NFE) and engineered barrier system (EBS) throughout the potential high-level nuclear waste repository at Yucca Mountain for a particular engineering design (CRWMS M&O 2000c). The process-level model will provide thermohydrologic (TH) information and data (such as in-drift temperature, relative humidity, liquid saturation, etc.) for use in other technical products. This data is provided throughout the entire repository area as a function of time. The MSTHM couples the Smeared-heat-source Drift-scale Thermal-conduction (SDT), Line-average-heat-source Drift-scale Thermohydrologic (LDTH), Discrete-heat-source Drift-scale Thermal-conduction (DDT), and Smeared-heat-source Mountain-scale Thermal-conduction (SMT) submodels such that the flow of water and water vapor through partially-saturated fractured rock is considered. The MSTHM accounts for 3-D drift-scale and mountain-scale heat flow, repository-scale variability of stratigraphy and infiltration flux, and waste package (WP)-to-WP variability in heat output from WPs. All submodels use the nonisothermal unsaturated-saturated flow and transport (NUFT) simulation code. The MSTHM is implemented in several data-processing steps. The four major steps are: (1) submodel input-file preparation, (2) execution of the four submodel families with the use of the NUFT code, (3) execution of the multiscale thermohydrologic abstraction code (MSTHAC), and (4) binning …
Date: December 21, 2001
Creator: Buscheck, T.A.
Object Type: Report
System: The UNT Digital Library
The Particle Cleanliness Validation System (open access)

The Particle Cleanliness Validation System

The Particle Cleanliness Validation System (PCVS) is a combination of a surface particle collection tool and a microscope based data, reduction system for determining the particle cleanliness of mechanical and optical surfaces at LLNL. Livermore is currently constructing the National Ignition Facility (NIF), a large 192 beam laser system for studying fusion physics. The laser is entirely enclosed. in aluminum and stainless steel vessels containing several environments; air, argon, and vacuum. It contains uncoated optics as well as hard dielectric coated and softer solgel coated optics which are, to varying degrees, sensitive to opaque particles, translucent particles, and molecular contamination. To quantify the particulate matter on structural surfaces during vendor cleaning and installation, a novel instrument has been developed to-both collect surface particles and to quantify the number and size distribution of these particles. The particles are collected on membrane filter paper which is ''swiped'' on a test surface for a proscribed distance to collect sufficient particles to significantly exceed the cleanliness of the filter paper. The swipe paper is then placed into a cassette for protection from further. contamination and transported to a microscope with x-y motorized stage and image analysis software, The surface of the swipe paper is …
Date: December 21, 2001
Creator: Stowers, I.F. & Ravizza, D.L.
Object Type: Article
System: The UNT Digital Library
Review of D-T Experiments Relevant to Burning Plasma Issues (open access)

Review of D-T Experiments Relevant to Burning Plasma Issues

Progress in the performance of tokamak devices has enabled not only the production of significant bursts of fusion energy from deuterium-tritium (D-T) plasmas in the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET) but, more importantly, the initial study of the physics of burning magnetically confined plasmas. The TFTR and JET, in conjunction with the worldwide fusion effort, have studied a broad range of topics including magnetohydrodynamic stability, transport, wave-particle interactions, the confinement of energetic particles, and plasma boundary interactions. The D-T experiments differ in three principal ways from previous experiments: isotope effects associated with the use of deuterium-tritium fuel, the presence of fusion-generated alpha particles, and technology issues associated with tritium handling and increased activation. The effect of deuterium-tritium fuel and the presence of alpha particles is reviewed and placed in the perspective of the much large r worldwide database using deuterium fuel and theoretical understanding. Both devices have contributed substantially to addressing the scientific and technical issues associated with burning plasmas. However, future burning plasma experiments will operate with larger ratios of alpha heating power to auxiliary power and will be able to access additional alpha-particle physics issues. The scientific opportunities for extending our understanding …
Date: December 21, 2001
Creator: Hawryluk, R.J.
Object Type: Report
System: The UNT Digital Library
A Revised Magnitude and Distance Amplitude Correction (MDAC2) Procedure for Regional Seismic Discriminants: Theory and Testing at NTS (open access)

A Revised Magnitude and Distance Amplitude Correction (MDAC2) Procedure for Regional Seismic Discriminants: Theory and Testing at NTS

The Magnitude and Distance Amplitude Correction (MDAC; Taylor and Hartse, 1998; Taylor et al., 2002) procedure for correcting regional seismic amplitudes for seismic event identification has been modified to include more realistic earthquake source models and source scaling. In the MDAC2 formulation we generalize the Brune (1970) earthquake source spectrum to use a more physical apparent stress model that can represent non-constant stress-drop scaling. We also event include a parameter that allows for variable P-wave and S-wave comer frequency scaling, imposing some of the constraints of ratio correction techniques (Rodger and Walter, 2002). Very Stable moment magnitude measures (Mayeda et al., 2002) from regional coda wave envelopes that have been tied to independently derived regional seismic moments are incorporated. This eliminates two fitting parameters that were necessary in relating seismic moment to magnitude. The incorporation of Bayesian tomography to replace the assumption of a constant Q0 model is also described. These modifications allow for more flexibility in the MDAC grid-search procedure. The direct tie to regional seismic moment rather than body wave magnitude reduces effects of upper mantle bias on the corrected amplitudes. In this paper, we develop the theory and test the formulation on Nevada Test Site (NTS) data.
Date: December 21, 2001
Creator: Walter, W R & Taylor, S R
Object Type: Report
System: The UNT Digital Library
Short-Period RF Undulator for a SASE Nanometer source (open access)

Short-Period RF Undulator for a SASE Nanometer source

Analysis is described towards development of a RF undulator with a period < 1 cm, an undulator parameter K of the order of unity, and a gap greater than 2.25 mm. The application for the undulator is for a SASE source to produce 1 nm wavelength radiation using a low energy electron beam in the range 1-2 GeV. Particle orbit calculations in a conventional standing-wave resonator configuration show that the presence of a co-propagating component of RF field can cause deleterious motion for the undulating electrons that can seriously degrade their radiation spectrum. To obviate this problem, resonator designs were devised in which only the counter-propagating field components interact with the particles. Two resonator configurations with the same undulator parameter K = 0.4 have been devised and are described in this report.
Date: December 21, 2001
Creator: Hirshfield, Jay L.
Object Type: Report
System: The UNT Digital Library
The Use of Rice Hulls for Sustainable Control of NOx Emissions in Deep Space Missions (open access)

The Use of Rice Hulls for Sustainable Control of NOx Emissions in Deep Space Missions

The use of the activated carbon produced from rice hulls to control NOx emissions for the future deep space missions has been demonstrated. The optimal carbonization temperature range was found to be between 600 C and 750 C. The burnoff of 61.8% was found at 700 C in pyrolysis and 750 C in activation. The BET surface area of the activated carbon from rice hulls was determined to be 172 m{sup 2}/g when prepared at 700 C. The presence of oxygen in flue gas is essential for effective adsorption of NO by the activated carbon. On the contrary, water vapor inhibits the adsorption efficiency of NO. Consequently, water vapor in flue gas should be removed by drying agents before adsorption to ensure high NO adsorption efficiency. All of NO in the flue gas was removed for more than one and a half hours when 10% oxygen was present and using a ratio of the carbon weight to the flue gas flow rate (W/F) of 15.4 g-min/L. The reduction of the adsorbed NO to form N{sub 2} can be effectively accomplished under anaerobic conditions at 550 C. For NO saturated activated carbon, the loss of carbon mass was determined to be …
Date: December 21, 2001
Creator: Xu, X. H.; Shi, Y.; Chang, S. G.; Fisher, J. W.; Pisharody, S.; Moran, M. J. et al.
Object Type: Article
System: The UNT Digital Library
Annual Progress Report / Continuation Proposal (open access)

Annual Progress Report / Continuation Proposal

We have been performing basic materials science research on materials for anodes and cathodes in electrochemical cells. The work is a mix of electrochemical measurements and analysis of the materials by transmission electron microscopy and x-ray diffractometry. At present, our experimental work involves only materials for Li storage, but we have been finishing papers from our previous work on hydrogen-storage materials.
Date: November 21, 2001
Creator: Fultz, Brent
Object Type: Report
System: The UNT Digital Library
Are Published Minimum Vapor Phase Spark Ignition Energy Data Valid? (open access)

Are Published Minimum Vapor Phase Spark Ignition Energy Data Valid?

The use of sprayed flammable fluids as solvents in dissolution and cleaning processes demand detailed understanding of ignition and fire hazards associated with these applications. When it is not feasible to inert the atmosphere in which the spraying process takes place, then elimination of all possible ignition sources must be done. If operators are involved in the process, the potential for human static build-up and ultimate discharge is finite, and it is nearly impossible to eliminate. The specific application discussed in this paper involved the use of heated Dimethyl Sulfoxide (DMSO) to dissolve high explosives (HE). Search for properties of DMSO yielded data on flammability limits and flash point, but there was no published information pertaining to the minimum energy for electrical arc ignition. Due to the sensitivity of this procedure, The Hazards Control Department of Lawrence Livermore National Laboratory (LLNL) was tasked to determine the minimum ignition energy of DMSO aerosol and vapor an experimental investigation was thus initiated. Because there were no electrical sources in spray chamber, Human Electro-Static Discharge (HESD) was the only potential ignition source. Consequently, the electrostatic generators required for this investigation were designed to produce electrostatic arcs with the defined voltage and current pulse …
Date: November 21, 2001
Creator: Staggs, K J; Alvares, N J & Greenwood, D W
Object Type: Article
System: The UNT Digital Library
Challenges in Microbial Database Interoperability Interagency Microbe Project Working Group (open access)

Challenges in Microbial Database Interoperability Interagency Microbe Project Working Group

Currently, data of interest to microbial researchers is spread across hundreds of web-accessible data sources, each with a unique interface and data format. Researchers interact with a few of these sites when they analyze their data, but are not able to utilize the majority of them on a regular basis. There are two significant challenges that must be overcome to integrate this environment and allow researchers to efficiently perform data analysis across the entire set of relevant data, or at least a significant portion of it. The first is to provide consistent access to the large numbers of distributed, heterogeneous data sets that are currently distributed over the web. The second is to define the semantics of the data provided by the individual sites in such a way that semantic conflicts can be identified and, ideally, resolved. The first step in establishing any integrated environment, from a data warehouse to a multi-database system, is provide consistent access to all of the relevant sources. While the type of access required will vary based on the integration strategy chosen--for example federated systems use query-based access while warehouses may prefer access to the underlying database--the essence of this challenge remains the same. Thus, …
Date: November 21, 2001
Creator: Critchlow, Terence
Object Type: Report
System: The UNT Digital Library
Corrective Action Investigation Plan for Corrective Action Unit 168: Areas 25 and 26 Contaminated Materials and Waste Dumps, Nevada Test Site, Nevada (Rev. 0) includes Record of Technical Change No. 1 (dated 8/28/2002), Record of Technical Change No. 2 (dated 9/23/2002), and Record of Technical Change No. 3 (dated 6/2/2004) (open access)

Corrective Action Investigation Plan for Corrective Action Unit 168: Areas 25 and 26 Contaminated Materials and Waste Dumps, Nevada Test Site, Nevada (Rev. 0) includes Record of Technical Change No. 1 (dated 8/28/2002), Record of Technical Change No. 2 (dated 9/23/2002), and Record of Technical Change No. 3 (dated 6/2/2004)

This Corrective Action Investigation Plan contains the U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office's approach to collect data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit 168 under the Federal Facility Agreement and Consent Order. Corrective Action Unit 168 consists of a group of twelve relatively diverse Corrective Action Sites (CASs 25-16-01, Construction Waste Pile; 25-16-03, MX Construction Landfill; 25-19-02, Waste Disposal Site; 25-23-02, Radioactive Storage RR Cars; 25-23-18, Radioactive Material Storage; 25-34-01, NRDS Contaminated Bunker; 25-34-02, NRDS Contaminated Bunker; CAS 25-23-13, ETL - Lab Radioactive Contamination; 25-99-16, USW G3; 26-08-01, Waste Dump/Burn Pit; 26-17-01, Pluto Waste Holding Area; 26-19-02, Contaminated Waste Dump No.2). These CASs vary in terms of the sources and nature of potential contamination. The CASs are located and/or associated wit h the following Nevada Test Site (NTS) facilities within three areas. The first eight CASs were in operation between 1958 to 1984 in Area 25 include the Engine Maintenance, Assembly, and Disassembly Facility; the Missile Experiment Salvage Yard; the Reactor Maintenance, Assembly, and Disassembly Facility; the Radioactive Materials Storage Facility; and the Treatment Test Facility Building at Test Cell A. Secondly, the three CASs located in …
Date: November 21, 2001
Creator: U.S. Department of Energy, National Nuclear Security Administration Nevada
Object Type: Report
System: The UNT Digital Library
A Measurement System for Systematic Hydrological Characterization of Unsaturated Fractured Welded Tuff in a Mined Underground Tunnel (open access)

A Measurement System for Systematic Hydrological Characterization of Unsaturated Fractured Welded Tuff in a Mined Underground Tunnel

A field investigation of unsaturated flow through a lithophysal unit of fractured welded tuff containing lithophysal cavities has been initiated. To characterize flow in this spatially heterogeneous medium, a systematic approach has been developed to perform tests in boreholes drilled at regular intervals in an underground tunnel (drift). In this paper, we describe the test equipment system that has been built for this purpose. Since the field-scale measurements, of liquid flow in the unsaturated, fractured rocks, require continuous testing for periods of days to weeks, the control of test equipment has been fully automated, allowing operation with no human presence at the field site. Preliminary results from the first set of tests are described. These tests give insight into the role of the matrix (perhaps also lithophysal cavities) as potential storage during the initial transient flow prior to the breakthrough of water at the drift crown, as well as the role of connected fractures that provide the subsequent quasi-steady flow. These tests also reveal the impact of evaporation on seepage into the drift.
Date: November 21, 2001
Creator: Cook, P. J.; Salve, R.; Freifeld, B. M. & Tsang, Y. W.
Object Type: Report
System: The UNT Digital Library