Pacific Northwest National Laboratory Annual Self-Evaluation Report: 2002 (open access)

Pacific Northwest National Laboratory Annual Self-Evaluation Report: 2002

This report will summarize PNNL's progress toward accomplishment of the critical outcomes, objectives and performance indicators as delineated in the FY 2002 Performance Evaluation and Fee Agreement. In addition, this report will summarize PNNL's analysis of the results of the FY2002 Peer Reviews, the implementation of PNNL's FY2002 Operational Improvement Initiatives, and the resolution of the Key Areas for Improvements.
Date: October 29, 2002
Creator: Cuello, Robert
Object Type: Report
System: The UNT Digital Library
Acoustic Filtration, Fractionation, and Mixing in Microfluidic Systems (open access)

Acoustic Filtration, Fractionation, and Mixing in Microfluidic Systems

This project is concerned with the research and development of a technique to manipulate small particles using acoustic energy coupled into a fluid filled plastic or glass sample chamber. These resulting miniaturized systems combine high functionality with an inexpensive, disposable sample chamber. Our approach to this problem is based on a combination of sophisticated modeling tools in conjunction with laboratory experiments. The design methodology is summarized in Figure 1. The process begins by investigating a wide range of device parameters using a one-dimensional analytical approximation. The results of these initial parameter studies are incorporated into a sophisticated three-dimensional multi-physics finite element code. From these simulations the optimized designs are prototyped and experimentally tested. The results of the experimental observations are then used to improve analytical approximations and the process is repeated as necessary.
Date: February 4, 2002
Creator: Wang, A & Fisher, K
Object Type: Report
System: The UNT Digital Library
Thermal Cook-off of an HMX Based Explosive: Pressure Gauge Experiments and Modeling (open access)

Thermal Cook-off of an HMX Based Explosive: Pressure Gauge Experiments and Modeling

Safety issues related to thermal cook-off are important for handling and storing explosive devices. Violence of event as a function of confinement is important for prediction of collateral events. There are major issues, which require an understanding of the following events: (1) transit to detonation of a pressure wave from a cook-off event, (2) sensitivity of HMX based explosives changes with thermally induced phase transitions and (3) the potential danger of neighboring explosive devices being affected by a cook-off reaction. Results of cook-off events of known size, confinement and thermal history allows for development and/or calibrating computer models for calculating events that are difficult to measure experimentally.
Date: April 2, 2002
Creator: Urtiew, P A; Forbes, J W; Tarver, C M; Garcia, F; Greenwood, D W & Vandersall, K S
Object Type: Article
System: The UNT Digital Library
Stability Affects of Artificial Viscosity in Detonation Modeling (open access)

Stability Affects of Artificial Viscosity in Detonation Modeling

Accurate multi-dimensional modeling of detonation waves in solid HE materials is a difficult task. To treat applied problems which contain detonation waves one must consider reacting flow with a wide range of length-scales, non-linear equations of state (EOS), and material interfaces at which the detonation wave interacts with other materials. To be useful numerical models of detonation waves must be accurate, stable, and insensitive to details of the modeling such as the mesh spacing, and mesh aspect ratio for multi-dimensional simulations. Studies we have performed show that numerical simulations of detonation waves can be very sensitive to the form of the artificial viscosity term used. The artificial viscosity term is included in our ALE hydrocode to treat shock discontinuities. We show that a monotonic, second order artificial viscosity model derived from an approximate Riemann solver scheme can strongly damp unphysical oscillations in the detonation wave reaction zone, improving the detonation wave boundary wall interaction. These issues are demonstrated in 2D model simulations presented of the 'Bigplate' test. Results using LX-I 7 explosives are compared with numerical simulation results to demonstrate the affects of the artificial viscosity model.
Date: June 3, 2002
Creator: Vitello, P & Souers, P C
Object Type: Article
System: The UNT Digital Library
Electrochemical Behavior of Alloy 22 in 5 M CaC12 (open access)

Electrochemical Behavior of Alloy 22 in 5 M CaC12

The corrosion resistance of Alloy 22 (UNS No.: N06022) was studied in 5 M CaCl{sub 2} electrolyte at various temperatures. Potentiodynamic polarization was used to examine the electrochemical behavior and measure the key potentials. Alloy 22 was found to be susceptible to localized corrosion in this high chloride [10M Cl{sup -}] environment at temperatures as low as 6O C.
Date: May 30, 2002
Creator: Ilevbare, G O
Object Type: Article
System: The UNT Digital Library
Search for X-Ray Induced Acceleration of the Decay of the 31-yr Isomer 178Hf Using Synchrotron Radiation (open access)

Search for X-Ray Induced Acceleration of the Decay of the 31-yr Isomer 178Hf Using Synchrotron Radiation

Releasing the energy stored in an isomeric nuclear state in a controlled way with an atomic or electromagnetic trigger is an attractive speculation: the energy gain may be on the order of the ratio of nuclear/atomic energies - MeV/keV. (Nuclear isomers are loosely defined as excited nuclear states with lifetimes longer than 10{sup -9} s.) Nuclear isomers, therefore, represent an opportunity for a stand-alone energy source if suitable schemes for trigger and control of the energy release can be found. Potential applications include space drive, as well as very bright {gamma}-ray sources. The nucleus {sup 178}Hf has a nuclear isomer with excitation energy E{sub x} = 2.447 MeV. The 2.447-MeV isomeric state decays slowly (t{sub 1/2} = 31 y) to the nearby state at 2.433 MeV. The J{sup {pi}} = 13{sup -} state loses energy in a rapid (t {approx} 10{sup -12} s) {gamma}-ray cascade ending at the 8{sup -} rotational band head which in turn decays via the ground-state rotational band cascade. The {gamma}-ray cascade is delayed at the 8{sup -} state at 1.147 MeV, since the 8{sup -} state is also isomeric, with t{sub 1/2} = 4 s. Very scarce quantities of the 16{sup +}, 31-yr isomer are …
Date: May 9, 2002
Creator: Ahmad, I.; Banar, J. C.; Becker, J. A.; Gemmell, D. S.; Kraemer, A.; Mashayekhi, A. et al.
Object Type: Report
System: The UNT Digital Library
Experimental and Modeling Studies of Water-Silica-PDMS Interactions in M97-Based Stress Cushions (open access)

Experimental and Modeling Studies of Water-Silica-PDMS Interactions in M97-Based Stress Cushions

In filled PDMS based composites, such as M97XX stress cushions, significant mechanical reinforcement of the polymer component is obtained from hydrogen bonding between the silica filler surface hydroxyls and the siloxane polymer backbone. It is expected that these interactions are influenced by the amount and structure of interfacial water. We have chosen to investigate in detail the effect of chemisorbed and physisorbed water on the interfacial structure and dynamics in silica-filled PDMS-based composites. Toward this end, we have combined classical molecular dynamics simulations and experimental studies employing nanoindentation, temperature programmed desorption (TPD), Dynamic Mechanical Analysis (DMA), and Nuclear Magnetic Resonance (NMR) analyses. Our TPD results suggest that moisture desorption and adsorption in M9787 can be approximated by the interaction of its silica constituents (Cab-0-Sil-M-7D and Hi-Sil-233) with moisture. Our experimental data also reveal that, in general, as heat-treated silica particles are exposed to moisture, chemisorbed states, then physisorbed states are gradually filled up in that order. Molecular modeling results suggest that the polymer-silica contact distance and the mobility of interfacial polymer chains significantly decreased as the hydration level at the interface was reduced. The reduced mobility of the PDMS chains in the interfacial domain reduced the bulk motional properties of …
Date: April 18, 2002
Creator: Maxwell, R; Dinh, L; Gee, R & Balazs, B
Object Type: Article
System: The UNT Digital Library
A Catalog of Vadose Zone Hydraulic Properties for the Hanford Site (open access)

A Catalog of Vadose Zone Hydraulic Properties for the Hanford Site

To predict contaminant release to the groundwater, it is necessary to understand the hydraulic properties of the material between the release point and the water table. Measurements of the hydraulic properties of the Hanford unsaturated sediments that buffer the water table are available from many areas of the site; however, the documentation is not well cataloged nor is it easily accessible. The purpose of this report is to identify what data is available for characterization of the unsaturated hydraulic properties at Hanford and Where these data can be found.
Date: September 30, 2002
Creator: Freeman, Eugene J.; Khaleel, Raziuddin & Heller, Paula R.
Object Type: Report
System: The UNT Digital Library
Effects of Globally Waste-Disturbing Activities on Gas Generation, Retention, and Release in Hanford Waste Tanks (open access)

Effects of Globally Waste-Disturbing Activities on Gas Generation, Retention, and Release in Hanford Waste Tanks

Various operations are authorized in Hanford single- and double-shell tanks that disturb all or a large fraction of the waste. These globally waste-disturbing activities have the potential to release a large fraction of the retained flammable gas and to affect future gas generation, retention, and release behavior. This report presents analyses of the expected flammable gas release mechanisms and the potential release rates and volumes resulting from these activities. The background of the flammable gas safety issue at Hanford is summarized, as is the current understanding of gas generation, retention, and release phenomena. Considerations for gas monitoring and assessment of the potential for changes in tank classification and steady-state flammability are given.
Date: December 18, 2002
Creator: Stewart, Charles W.; Huckaby, James L. & Meyer, Perry A.
Object Type: Report
System: The UNT Digital Library
Particle Correlations with the PHENIX Experiment (open access)

Particle Correlations with the PHENIX Experiment

Results of identical pion correlations from the first year of data collection with the PHENIX detector at RHIC ({radical}S{sub NN} = 130 GeV) are presented. PHENIX has good particle identification using an electromagnetic calorimeter for timing, leading to identified pions from .2 to 1 GeV/c. This extends the range of previously measured correlation radii at this energy to (k{sub T}) = 633MeV/c. The beam energy dependence of the HBT radii are studied in depth and no significant dependence of the transverse radii is present. The longitudinal correlation length has a moderate energy dependence. Furthermore, theoretical predictions of R{sub out}/R{sub side} severely underpredict the measured ratio, which is consistent with unity for all k{sub T}. The implications of these results are considered.
Date: January 20, 2002
Creator: Johnson, S C
Object Type: Article
System: The UNT Digital Library
Classification of Bent-Double Galaxies: Experiences with Ensembles of Decision Trees (open access)

Classification of Bent-Double Galaxies: Experiences with Ensembles of Decision Trees

In earlier work, we have described our experiences with the use of decision tree classifiers to identify radio-emitting galaxies with a bent-double morphology in the FIRST astronomical survey. We now extend this work to include ensembles of decision tree classifiers, including two algorithms developed by us. These algorithms randomize the decision at each node of the tree, and because they consider fewer candidate splitting points, are faster than other methods for creating ensembles. The experiments presented in this paper with our astronomy data show that our algorithms are competitive in accuracy, but faster than other ensemble techniques such as Boosting, Bagging, and Arcx4 with different split criteria.
Date: January 8, 2002
Creator: Kamath, C & Cantu-Paz, E
Object Type: Article
System: The UNT Digital Library
Microfluidic Tools for Biological Sample Preparation (open access)

Microfluidic Tools for Biological Sample Preparation

Researchers at Lawrence Livermore National Laboratory are developing means to collect and identify fluid-based biological pathogens in the forms of proteins, viruses, and bacteria. To support detection instruments, we are developing a flexible fluidic sample preparation unit. The overall goal of this Microfluidic Module is to input a fluid sample, containing background particulates and potentially target compounds, and deliver a processed sample for detection. We are developing techniques for sample purification, mixing, and filtration that would be useful to many applications including immunologic and nucleic acid assays. Sample preparation functions are accomplished with acoustic radiation pressure, dielectrophoresis, and solid phase extraction. We are integrating these technologies into packaged systems with pumps and valves to control fluid flow and investigating small-scale detection methods.
Date: April 10, 2002
Creator: Visuri, S R; Ness, K; Dzenitis, J; Benett, B; Bettencourt, K; Hamilton, J et al.
Object Type: Article
System: The UNT Digital Library
Effects of Introduced Materials in the Drift Scale Test (open access)

Effects of Introduced Materials in the Drift Scale Test

Water samples previously acquired from superheated (>140 C) zones within hydrological test boreholes of the Drift Scale Test (DST) show relatively high fluoride concentrations (5-66 ppm) and low pH (3.1-3.5) values. In these high temperature regions of the rock, water is present superheated vapor only--liquid water for sampling purposes is obtained during the sampling process by cooling. Based on data collected to date, it is evident that the source of the fluoride and low pH is from introduced man-made materials (Teflon{trademark} and/or Viton{trademark} fluoroelastomer) used in the test. The test materials may contribute fluoride either by degassing hydrogen fluoride (HF) directly to produce trace concentrations of HF gas ({approx}0.1 ppm) in the high temperature steam, or by leaching fluoride in the sampling tubes after condensation of the superheated steam. HF gas is known to be released from Viton{trademark} at high temperatures (Dupont Dow Elastomers L.L.C., Elkton, MD, personal communication) and the sample water compositions indicate near stoichiometric balance of hydrogen ion and fluoride ion, indicating dissolution of HF gas into the aqueous phase. These conclusions are based on a series of water samples collected to determine if the source of the fluoride is from the degradation of materials originally installed …
Date: January 11, 2002
Creator: DeLoach, L & Jones, RL
Object Type: Report
System: The UNT Digital Library
Russian Geologic Repository Technical Papers and Reports (open access)

Russian Geologic Repository Technical Papers and Reports

Lawrence Livermore National Laboratory (LLNL) has been actively and continuously engaged in Russian geologic disposal activities since 1995. The first joint US-Russian meeting on Disposition of Excess Weapons Plutonium was held in January 1995 at Los Alamos National Laboratory (LANL). The meeting resulted in the appointment of Dr. L. J. Jardine from LLNL and Dr. T. A. Gupalo from the All-Russian Research and Design Institute of Production Engineering (VNIPIPT) as the US-Russian Federation (RF) joint co-chairs for geologic disposal of plutonium-containing materials, respectively. The initial joint studies focused on the geologic disposal of plutonium-containing materials and immobilized plutonium waste forms. These studies started in 1995, and continue in 2002. The first joint work of LLNL and VNIPIPT was documented in the October 1996 Paris P8 Nuclear Experts Meeting [1]. In summary, LLNL has been actively and continuously involved in various ways since 1995 in developing and participating in the current Russian geologic disposal program activities near the Mayak and MCC K-26 sites. Figure 1 illustrates how these various LLNL activities have been integrated, coordinated, and focused on developing geologic disposal in Russia. The various LLNL contracts are shown in the figure with the specific LLNL contract number. Reference 13 provides …
Date: February 18, 2002
Creator: Jardine, L
Object Type: Report
System: The UNT Digital Library
Steam System Opportunity Assessment for the Pulp and Paper, Chemical Manufacturing, and Petroleum Refining Industries: Main Report (open access)

Steam System Opportunity Assessment for the Pulp and Paper, Chemical Manufacturing, and Petroleum Refining Industries: Main Report

This report assesses steam generation and use in the pulp and paper, chemical, and petroleum refining industries, and estimates the potential for energy savings from implementation of steam system performance and efficiency improvements.
Date: October 1, 2002
Creator: unknown
Object Type: Book
System: The UNT Digital Library
Solar Decathlon: Collegiate Challenge to Build the Future; Preprint (open access)

Solar Decathlon: Collegiate Challenge to Build the Future; Preprint

A new collegiate competition, called the Solar Decathlon, is under way. Fourteen teams from colleges and universities across the United States, including Puerto Rico, will assemble on the National Mall in Washington, DC, in late September 2002. They will compete to capture, convert, store, and use enough solar energy to power small, solar-powered, energy-efficient homes that they have designed, built, and transported to the site. Solar Decathletes will be required to provide all the energy for an entire household, including a home-based business and the transportation needs of the household and business. During the event, only the solar energy available within the perimeter of each house may be used to generate the power needed to compete in the ten Solar Decathlon contests. The event is sponsored by the U.S. Department of Energy, National Renewable Energy Laboratory, and private-sector partners BP Solar, American Institute of Architects, Electronic Data Systems, and Home Depot.
Date: May 1, 2002
Creator: Warner, C.; King, R.; Nahan, R. & Eastment, M.
Object Type: Article
System: The UNT Digital Library
Temperature and Wavelength Dependent Emissivity of a Shocked Surface: A First Experiment (open access)

Temperature and Wavelength Dependent Emissivity of a Shocked Surface: A First Experiment

We have conducted an experiment in which the temperature and the wavelength dependent emissivity of a shocked surface has been measured. In the past, only the thermal emission from the shocked surface has been measured. The lack of knowledge of the emissivity as a function of wavelength leads to uncertainty in converting the measured emission spectrum into a surface temperature. We have developed a technique by which we are able to calculate both the emissivity of the shocked surface over a range of relevant wavelengths and the temperature of the surface. We use a multi-channel spectrometer in combination with a pulsed light source having a known spectrum of infrared radiation. Two separate techniques using a pulse of reflected radiation are employed and described. Both give the same result: An initially polished molybdenum surface that is shocked and partially released has a temperature of 1040 degrees Kelvin and a wavelength ({lambda}) dependent emissivity of 0.16 ({lambda}=1.2{micro}m), 0.10 ({lambda} =1.6 {micro}m), and 0.20 ({lambda} =2.3 {micro}m).
Date: January 25, 2002
Creator: Poulsen, P & Hare, D E
Object Type: Article
System: The UNT Digital Library
Chemistry at Extreme Conditions (open access)

Chemistry at Extreme Conditions

We present equation of state results from impulsively stimulated light scattering (ISLS) experiments conducted in diamond anvil cells on pure supercritical fluids. We have made measurements on fluid H{sub 2}O (water), and CH{sub 3}OH (methanol). Sound speeds measured through ISLS have allowed us to refine existing potential models used in the exponential-6 (EXP-6) detonation product library [Fried, L. E., and Howard, W. M., J. Chem. Phys. 109 (17): 7338-7348 (1998).]. The refined models allow us to more accurately assess the chemical composition at the Chapman-Jouget (C-J) state of common energetic materials. We predict that water is present in appreciable quantities at the C-J state of energetic materials HMX, RDX, and nitro methane.
Date: August 8, 2002
Creator: Zaug, J M; Fried, L E; Abramson, E H; Hansen, D W; Crowhurst, J C & Howard, W M
Object Type: Article
System: The UNT Digital Library
Coalescence of Multiple Plasmoids as a Means of Efficient Spheromak Formation (open access)

Coalescence of Multiple Plasmoids as a Means of Efficient Spheromak Formation

We have produced single bursts of helicity from the source in the SSPX spheromak in order to study the efficiency of the simplest example of helicity injection. We find that the helicity injection rate can be written in terms of the injected current and an inductance, and that a simple circuit analogue demonstrates unambiguously the relationship of helicity to energy: helicity injection is the addition of inductive loops. While helicity balance points to the conservation of helicity, the electrical efficiency is around 15%. However, in the expulsion of the loop, electrical energy is converted to directional motion, which may be recoverable usefully as heat by collisions, thus the efficiency of the injection process is arguably quite high. Integral to this notion of helicity injection is the idea that reconnection is necessary: without disconnection from the source by a reconnection event, the spheromak fields are just proportional to the injected current. Sometimes the multiple bursts occur spontaneously and cause a step-wise increase in the field (and helicity). However, in all instances when the current remains above the ejection threshold for t > 50 {micro}s, the n=l mode initiates and builds field, although with much reduced efficiency, and to a level which …
Date: February 28, 2002
Creator: Woodruff, S; McLean, H S & Stallard, B W
Object Type: Article
System: The UNT Digital Library
UNIVERSAL BEHAVIOR OF CHARGED PARTICLE PRODUCTION IN HEAVY ION COLLISIONS. (open access)

UNIVERSAL BEHAVIOR OF CHARGED PARTICLE PRODUCTION IN HEAVY ION COLLISIONS.

The PHOBOS experiment at RHIC has measured the multiplicity of primary charged particles as a function of centrality and pseudorapidity in Au+Au collisions at {radical}(s{sub NN}) = 19.6, 130 and 200 GeV. Two observations indicate universal behavior of charged particle production in heavy ion collisions. The first is that forward particle production, over a range of energies, follows a universal limiting curve with a non-trivial centrality dependence. The second arises from comparisons with pp/{bar p}p and e{sup +}e{sup -} data. <Nch>/<N{sub part}/2> in nuclear collisions at high energy scales with {radical}s in a similar way as N{sub ch} in e{sup +}e{sup -} collisions and has a very weak centrality dependence. These features may be related to a reduction in the leading particle effect due to the multiple collisions suffered per participant in heavy ion collisions.
Date: July 24, 2002
Creator: STEINBERG,P. A. FOR THE PHOBOS COLLABORATION
Object Type: Article
System: The UNT Digital Library
Polycrystalline Thin Film Photovoltaics: Research, Development, and Technologies: Preprint (open access)

Polycrystalline Thin Film Photovoltaics: Research, Development, and Technologies: Preprint

II-VI binary thin-film solar cells based on cadmium telluride (CdTe) and I-III-VI ternary thin-film solar cells based on copper indium diselenide (CIS) and related materials have been the subject of intense research and development in the past few years. Substantial progress has been made thus far in the area of materials research, device fabrication, and technology development, and numerous applications based on CdTe and CIS have been deployed worldwide. World record efficiency of 16.5% has been achieved by NREL scientists for a thin-film CdTe solar cell using a modified device structure. Also, NREL scientists achieved world-record efficiency of 21.1% for a thin-film CIGS solar cell under a 14X concentration and AM1.5 global spectrum. When measured under a AM1.5 direct spectrum, the efficiency increases to 21.5%. Pathways for achieving 25% efficiency for tandem polycrystalline thin-film solar cells are elucidated. R&D issues relating to CdTe and CIS are reported in this paper, such as contact stability and accelerated life testing in CdTe, and effects of moisture ingress in thin-film CIS devices. Substantial technology development is currently under way, with various groups reporting power module efficiencies in the range of 7.0% to 12.1% and power output of 40.0 to 92.5 W. A number …
Date: May 1, 2002
Creator: Ullal, H. S.; Zweibel, K. & von Roedern, B.
Object Type: Article
System: The UNT Digital Library
Signaling to the P53 Tumor Suppressor Through Pathways Activated by Genotoxic and Non-Genotoxic Stresses. (open access)

Signaling to the P53 Tumor Suppressor Through Pathways Activated by Genotoxic and Non-Genotoxic Stresses.

The p53 tumor suppressor is a tetrameric transcription factor that is post-translational modified at {approx}18 different sites by phosphorylation, acetylation, or sumoylation in response to various cellular stress conditions. Specific posttranslational modifications, or groups of modifications, that result from the activation of different stress-induced signaling pathways are thought to modulate p53 activity to regulate cell fate by inducing cell cycle arrest, apoptosis, or cellular senescence. Here we review the posttranslational modifications to p53 and the pathways that produce them in response to both genotoxic and non-genotoxic stresses.
Date: July 1, 2002
Creator: Anderson, C. W. & Appella, E.
Object Type: Book
System: The UNT Digital Library
Status of the IEEE P1547 Draft Interconnection Standard and Distributed Energy Resources R&D: Preprint (open access)

Status of the IEEE P1547 Draft Interconnection Standard and Distributed Energy Resources R&D: Preprint

The Department of Energy (DOE) Distributed Power Program (DPP) is conducting work to complete, validate in the field, and support the development of a national interconnection standard for distributed energy resources (DER), and to address the institutional and regulatory barriers slowing the commercial adoption of DER systems. This work includes support for the IEEE standards, including P1547 Standard for Interconnecting Distributed Resources with Electric Power Systems, P1589 Standard for Conformance Test Procedures for Equipment Interconnecting Distributed Resources with Electric Power Systems, and the P1608 Application Guide. Work is also in progress on system integration research and development (R&D) on the interface and control of DER with local energy systems. Additional efforts are supporting high-reliability power for industry, evaluating innovative concepts for DER applications, and exploring plug-and-play interface and control technologies for intelligent autonomous interconnection systems. This paper summarizes (1) the current status of the IEEE interconnection standards and application guides in support of DER, and (2) the R&D in progress at the National Renewable Energy Laboratory (NREL) for interconnection and system integration and application of distributed energy resources.
Date: May 1, 2002
Creator: Thomas, H. P.; Basso, T. S. & Kroposki, B.
Object Type: Article
System: The UNT Digital Library
Evaluation of the Radiochemistry of Near-Field Water Samples at the Nevada Test Site Applied to the Definition of a Hydrologic Source Term (open access)

Evaluation of the Radiochemistry of Near-Field Water Samples at the Nevada Test Site Applied to the Definition of a Hydrologic Source Term

Effective management of available groundwater resources and strategies for remediation of water impacted by past nuclear testing practices depend on knowledge about the migration of radionuclides in groundwater away from the sites of the explosions. A primary concern is to assess the relative mobilities of the different radionuclide species found near sites of underground nuclear tests and to determine the concentration, extent, and speed of this movement. Ultimately the long term transport behavior of radionuclides with half-lives long enough that they will persist for decades, their interaction with groundwater, and the resulting flux of these contaminants is of paramount importance. As part of a comprehensive approach to these assessments, more than three decades of site-specific sites studies have been undertaken at the Nevada Test Site (NTS) which have focused on the means responsible for the observed or suspected movement of radionuclides away from underground nuclear tests (RNM, 1983). More recently regional and local models of groundwater flow and radionuclide transport have been developed as part of a federal and state of Nevada program to assess the long-term effects of underground nuclear testing on human health and environment (e.g., U.S. DOE/NV, 1997a; Tompson et al., 1999; Pawloski et al., 2001). Necessary …
Date: July 5, 2002
Creator: Smith, D K
Object Type: Report
System: The UNT Digital Library