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On Ideal Stability of Cylindrical Localized Interchange Modes

Description: Stability of cylindrical localized ideal pressure-driven interchange plasma modes is revisited. Converting the underlying eigenvalue problem into the form of the Schroedinger equation gives a new simple way of deriving the Suydam stability criterion and calculating the growth rates of unstable modes. Near the marginal stability limit the growth rate is exponentially small and the mode has a double-peak structure.
Date: May 15, 2007
Creator: Umansky, M V
Partner: UNT Libraries Government Documents Department

Performance of the Integrated Tracker Towers of the GLAST Large Area Telescope

Description: The GLAST Large Area Telescope (LAT) is a high energy gamma ray observatory, mounted on a satellite that will be own in 2007. The LAT tracker consists of an array of tower modules, equipped with planes of silicon strip detectors (SSDs) interleaved with tungsten converter layers. Photon detection is based on the pair conversion process; silicon strip detectors will reconstruct tracks of electrons and positrons. The instrument is actually being assembled. The first towers have been already tested and integrated at Stanford Linear Accelerator Center (SLAC). An overview of the integration stages of the main components of the tracker and a description of the pre-launch tests will be given. Experimental results on the performance of the tracker towers will be also discussed.
Date: February 15, 2007
Creator: Brigida, M.; Caliandro, A.; Favuzzi, C.; Fusco, P.; Gargano, F.; Giglietto, N. et al.
Partner: UNT Libraries Government Documents Department

GAMMA-RAY COMPTON LIGHT SOURCE DEVELOPMENT AT LLNL

Description: A new class of tunable, monochromatic {gamma}-ray sources capable of operating at high peak and average brightness is currently being developed at LLNL for nuclear photoscience and applications. These novel systems are based on Compton scattering of laser photons by a high brightness relativistic electron beam produced by an rf photoinjector. A prototype, capable of producing > 10{sup 8} 0.7 MeV photons in a single shot, with a fractional bandwidth of 1%, and a repetition rate of 10 Hz, is currently under construction at LLNL; this system will be used to perform nuclear resonance fluorescence experiments. A new symmetrized S-band rf gun, using a Mg photocathode, will produce up to 1 nC of charge in an 8 ps bunch, with a normalized emittance modeled at 0.8 mm.mrad; electrons are subsequently accelerated up to 120 MeV to interact with a 500 mJ, 10 ps, 355 nm laser pulse and generate {gamma}-rays. The laser front end is a fiber-based system, using corrugated-fiber Bragg gratings for stretching, and drives both the frequency-quadrupled photocathode illumination laser and the Nd:YAG interaction laser. Two new technologies are used in the laser: a hyper-Michelson temporal pulse stacker capable of producing 8 ps square UV pulses, and a hyper-dispersion compressor for the interaction laser. Other key technologies, basic scaling laws, and recent experimental results will also be presented, along with an overview of future research and development directions.
Date: August 15, 2007
Creator: Hartemann, F V; Anderson, S G; Gibson, D J; Hagmann, C A; Johnson, M S; Jovanovic, I et al.
Partner: UNT Libraries Government Documents Department

Fracture-Flow-Enhanced Solute Diffusion into Fractured Rock

Description: We propose a new conceptual model of fracture-flow-enhanced matrix diffusion, which correlates with fracture-flow velocity, i.e., matrix diffusion enhancement induced by rapid fluid flow within fractures. According to the boundary-layer or film theory, fracture flow enhanced matrix diffusion may dominate mass-transfer processes at fracture-matrix interfaces, because rapid flow along fractures results in large velocity and concentration gradients at and near fracture-matrix interfaces, enhancing matrix diffusion at matrix surfaces. In this paper, we present a new formulation of the conceptual model for enhanced fracture-matrix diffusion, and its implementation is discussed using existing analytical solutions and numerical models. In addition, we use the enhanced matrix diffusion concept to analyze laboratory experimental results from nonreactive and reactive tracer breakthrough tests, in an effort to validate the new conceptual model.
Date: December 15, 2007
Creator: Wu, Yu-Shu; Ye, Ming & Sudicky, E.A.
Partner: UNT Libraries Government Documents Department

Hot Topics from the BABAR Experiment

Description: With a sample of about 384 million B{bar B} pairs recorded with the BABAR detector, we search for the flavor-changing charged current transition B{sup {+-}} {yields} {tau}{+-}{upsilon} and perform an amplitude analysis of the effective flavor-changing neutral current transition B{sup {+-}} {yields} {var_phi}(1020)K*(892){+-}. We also extend our search for other K* final states in the decay B{sup 0} {yields} {var_phi}(1020)K*0 with a large K*0 {yields} K{sup +}{pi}{sup -} invariant mass. Two samples of events with one reconstructed hadronic B decay or one reconstructed semileptonic B decay are selected, and in the recoil a search for B{sup {+-}} {yields} {tau}{+-}{upsilon} is performed. We find a 2.6 {sigma} (3.2 {sigma} not including expected background uncertainty) excess in data which can be converted to a preliminary branching fraction central value of {beta}(B{sup {+-}} {yields} {tau}{+-}{upsilon}) = (1.20{sup +0.40+0.29}{sub -0.38-0.30} {+-} 0.22) x 10{sup -4}. With the decay B{sup {+-}} {yields} {var_phi}(1020)K*(892){sup {+-}}, twelve parameters are measured, where our measurements of f{sub L} = 0.49 {+-} 0.05 {+-} 0.03, f{sub {perpendicular}} = 0.21 {+-} 0.05 {+-} 0.02, and the strong phases point to the presence of a substantial helicity-plus amplitude from a presently unknown source.
Date: June 15, 2007
Creator: Gritsan, A.V. & U., /Johns Hopkins
Partner: UNT Libraries Government Documents Department

Electron Energy Distributions at Relativistic Shock Sites: Observational Constraints from the Cygnus A Hotspots

Description: We report new detections of the hotspots in Cygnus A at 4.5 and 8.0 microns with the Spitzer Space Telescope. Together with detailed published radio observations and synchrotron self-Compton modeling of previous X-ray detections, we reconstruct the underlying electron energy spectra of the two brightest hotspots (A and D). The low-energy portion of the electron distributions have flat power-law slopes (s {approx} 1.5) up to the break energy which corresponds almost exactly to the mass ratio between protons and electrons; we argue that these features are most likely intrinsic rather than due to absorption effects. Beyond the break, the electron spectra continue to higher energies with very steep slopes s>3. Thus, there is no evidence for the 'canonical' s=2 slope expected in 1st order Fermi-type shocks within the whole observable electron energy range. We discuss the significance of these observations and the insight offered into high-energy particle acceleration processes in mildly relativistic shocks.
Date: October 15, 2007
Creator: Cheung, C.C.Teddy; Stawarz, L.; Harris, D.E. & Ostrowski, M.
Partner: UNT Libraries Government Documents Department

Advanced Safeguards Approaches for New Fast Reactors

Description: This third report in the series reviews possible safeguards approaches for new fast reactors in general, and the ABR in particular. Fast-neutron spectrum reactors have been used since the early 1960s on an experimental and developmental level, generally with fertile blanket fuels to “breed” nuclear fuel such as plutonium. Whether the reactor is designed to breed plutonium, or transmute and “burn” actinides depends mainly on the design of the reactor neutron reflector and the whether the blanket fuel is “fertile” or suitable for transmutation. However, the safeguards issues are very similar, since they pertain mainly to the receipt, shipment and storage of fresh and spent plutonium and actinide-bearing “TRU”-fuel. For these reasons, the design of existing fast reactors and details concerning how they have been safeguarded were studied in developing advanced safeguards approaches for the new fast reactors. In this regard, the design of the Experimental Breeder Reactor-II “EBR-II” at the Idaho National Laboratory (INL) was of interest, because it was designed as a collocated fast reactor with a pyrometallurgical reprocessing and fuel fabrication line – a design option being considered for the ABR. Similarly, the design of the Fast Flux Facility (FFTF) on the Hanford Site was studied, because it was a successful prototype fast reactor that ran for two decades to evaluate fuels and the design for commercial-scale fast reactors.
Date: December 15, 2007
Creator: Durst, Philip C.; Therios, Ike; Bean, Robert; Dougan, A.; Boyer, Brian; Wallace, Rick L. et al.
Partner: UNT Libraries Government Documents Department

Advanced Safeguards Approaches for New TRU Fuel Fabrication Facilities

Description: This second report in a series of three reviews possible safeguards approaches for the new transuranic (TRU) fuel fabrication processes to be deployed at AFCF – specifically, the ceramic TRU (MOX) fuel fabrication line and the metallic (pyroprocessing) line. The most common TRU fuel has been fuel composed of mixed plutonium and uranium dioxide, referred to as “MOX”. However, under the Advanced Fuel Cycle projects custom-made fuels with higher contents of neptunium, americium, and curium may also be produced to evaluate if these “minor actinides” can be effectively burned and transmuted through irradiation in the ABR. A third and final report in this series will evaluate and review the advanced safeguards approach options for the ABR. In reviewing and developing the advanced safeguards approach for the new TRU fuel fabrication processes envisioned for AFCF, the existing international (IAEA) safeguards approach at the Plutonium Fuel Production Facility (PFPF) and the conceptual approach planned for the new J-MOX facility in Japan have been considered as a starting point of reference. The pyro-metallurgical reprocessing and fuel fabrication process at EBR-II near Idaho Falls also provided insight for safeguarding the additional metallic pyroprocessing fuel fabrication line planned for AFCF.
Date: December 15, 2007
Creator: Durst, Philip C.; Ehinger, Michael H.; Boyer, Brian; Therios, Ike; Bean, Robert; Dougan, A. et al.
Partner: UNT Libraries Government Documents Department

Radio Loudness of AGNs: Host Galaxy Morphology and the Spin Paradigm

Description: We investigate how the total radio luminosity of AGN-powered radio sources depends on their accretion luminosity and the central black hole mass. We find that AGNs form two distinct and well separated sequences on the radio-loudness -- Eddington-ratio plane. We argue that these sequences mark the real upper bounds of radio-loudness of two distinct populations of AGNs: those hosted respectively by elliptical and disk galaxies. Both sequences show the same dependence of the radio-loudness on the Eddington ratio (an increase with decreasing Eddington ratio), which suggests that another parameter in addition to the accretion rate must play a role in determining the jet production efficiency in active galactic nuclei, and that this parameter is related to properties of the host galaxy. The revealed host-related radio dichotomy breaks down at high accretion rates where the dominant fraction of luminous quasars hosted by elliptical galaxies is radio quiet. We argue that the huge difference between the radio-loudness reachable by AGNs in disc and elliptical galaxies can be explained by the scenario according to which the spin of a black hole determines the outflows power, and central black holes can reach large spins only in early type galaxies (following major mergers), and not (in a statistical sense) in spiral galaxies.
Date: October 15, 2007
Creator: Stawarz, L.; Sikora, M. & Lasota, J.-P.
Partner: UNT Libraries Government Documents Department

Radiogenic and Stable Isotope and Hydrogeochemical Investigation of Groundwater, Pajarito Plateau and Surrounding Areas, New Mexico

Description: From October 2004 through February 2006, Los Alamos National Laboratory, the New Mexico Environment Department-Department of Energy Oversight Bureau, and the United States Geological Survey conducted a hydrochemical investigation. The purpose of the investigation was to evaluate groundwater flow paths and determine groundwater ages using tritium/helium-3 and carbon-14 along with aqueous inorganic chemistry. Knowledge of groundwater age and flow paths provides a technical basis for selecting wells and springs for monitoring. Groundwater dating is also relevant to groundwater resource management, including aquifer sustainability, especially during periods of long-term drought. At Los Alamos, New Mexico, groundwater is either modern (post-1943), submodern (pre-1943), or mixed (containing both pre- and post-1943 components). The regional aquifer primarily consists of submodern groundwater. Mixed-age groundwater results from initial infiltration of surface water, followed by mixing with perched alluvial and intermediate-depth groundwater and the regional aquifer. No groundwater investigation is complete without using tritium/helium-3 and carbon-14 dating methods to quantify amounts of modern, mixed, and/or submodern components present in samples. Computer models of groundwater flow and transport at Los Alamos should be calibrated to groundwater ages for perched intermediate zones and the regional aquifer determined from this investigation. Results of this study clearly demonstrate the occurrence of multiple flow paths and groundwater ages occurring within the Sierra de los Valles, beneath the Pajarito Plateau, and at the White Rock Canyon springs. Localized groundwater recharge occurs within several canyons dissecting the Pajarito Plateau. Perched intermediate-depth groundwater and the regional aquifer beneath Pueblo Canyon, Los Alamos Canyon, Sandia Canyon, Mortandad Canyon, Pajarito Canyon, and Canon de Valle contain a modern component. This modern component consists of tritium, nitrate, perchlorate, chromate, boron, uranium, and/or high explosive compounds. It is very unlikely that there is only one transport or travel time, ranging from 25 to 62 years, for these conservative chemicals ...
Date: July 15, 2007
Creator: Longmire, Patrick; Dale, Michael; Counce, Dale; Manning, Andrew; Larson, Toti; Granzow, Kim et al.
Partner: UNT Libraries Government Documents Department

On the Properties of Plastic Ablators in Laser-Driven Material Dynamics Experiments

Description: Radiation hydrodynamics simulations were used to study the effect of plastic ablators in laser-driven shock experiments. The sensitivity to composition and equation of state was found to be 5-10% in ablation pressure. As was found for metals, a laser pulse of constant irradiance gave a pressure history which decreased by several percent per nanosecond. The pressure history could be made more constant by adjusting the irradiance history. The impedance mismatch with the sample gave an increase o(100%) in the pressure transmitted into the sample, for a reduction of several tens of percent in the duration of the peak load applied to the sample, and structured the release history by adding a release step to a pressure close to the ablation pressure. Algebraic relations were found between the laser pulse duration, the ablator thickness, and the duration of the peak pressure applied to the sample, involving quantities calculated from the equations of state of the ablator and sample using shock dynamics.
Date: November 15, 2007
Creator: Swift, D C & Kraus, R G
Partner: UNT Libraries Government Documents Department

Porphyrin-Based Photocatalytic Lithography

Description: Photocatalytic lithography is an emerging technique that couples light with coated mask materials in order to pattern surface chemistry. We excite porphyrins to create radical species that photocatalytically oxidize, and thereby pattern, chemistries in the local vicinity. The technique advantageously does not necessitate mass transport or specified substrates, it is fast and robust and the wavelength of light does not limit the resolution of patterned features. We have patterned proteins and cells in order to demonstrate the utility of photocatalytic lithography in life science applications.
Date: October 15, 2007
Creator: Bearinger, J; Stone, G; Christian, A; Dugan, L; Hiddessen, A; Wu, K J et al.
Partner: UNT Libraries Government Documents Department

First Results From GLAST-LAT Integrated Towers Cosmic Ray Data Taking And Monte Carlo Comparison

Description: GLAST Large Area Telescope (LAT) is a gamma ray telescope instrumented with silicon-strip detector planes and sheets of converter, followed by a calorimeter (CAL) and surrounded by an anticoincidence system (ACD). This instrument is sensitive to gamma rays in the energy range between 20 MeV and 300 GeV. At present, the first towers have been integrated and pre-launch data taking with cosmic ray muons is being performed. The results from the data analysis carried out during LAT integration will be discussed and a comparison with the predictions from the Monte Carlo simulation will be shown.
Date: February 15, 2007
Creator: Brigida, M.; Caliandro, A.; Favuzzi, C.; Fusco, P.; Gargano, F.; Giordano, F. et al.
Partner: UNT Libraries Government Documents Department

FERRITE-FREE, OIL-SWITCHED, FOUR-STAGE, HIGH-GRADIENT MODULE FOR COMPACT PULSED POWER APPLICATIONS

Description: We describe the design and present initial experimental results of a novel, high-gradient, compact pulsed power module. Our application focus is linear accelerators but our technology is easily applicable to a wide range of pulse-power applications. Our design incorporates and combines for the first time a number of our recently developed, enabling technologies including: a novel, bipolar pulse-forming line allowing module stacking without ferrites, very compact and fast oil filled switches, novel high-dielectric constant insulator/energy storage material, and a novel method for reducing edge enhancements in the pulse forming structure. The combination of these technologies enables us to design a very compact stackable module that will deliver high-gradient (5-10 MV/m) voltage at 5-10kA to arbitrary loads. Our prototype is comprised of four stages. Each stage is designed to operate at 300kV producing 1.2-MV into 120 Ohms. The pulse length is 25-ns and the pulse-shape is rectangular. We present initial experimental results up to 75 kV per stage with the switches operating in self-break mode.
Date: June 15, 2007
Creator: Rhodes, M. A.; Watson, J.; Sanders, D.; Sampayan, S. & Caporaso, G.
Partner: UNT Libraries Government Documents Department

ELECTROMAGNETIC SIMULATIONS OF LINEAR PROTON ACCELERATOR STRUCTURES USING DIELECTRIC WALL ACCELERATORS

Description: Proton accelerator structures for medical applications using Dielectric Wall Accelerator (DWA) technology allow for the utilization of high electric field gradients on the order of 100 MV/m to accelerate the proton bunch. Medical applications involving cancer therapy treatment usually desire short bunch lengths on the order of hundreds of picoseconds in order to limit the extent of the energy deposited in the tumor site (in 3D space, time, and deposited proton charge). Electromagnetic simulations of the DWA structure, in combination with injections of proton bunches have been performed using 3D finite difference codes in combination with particle pushing codes. Electromagnetic simulations of DWA structures includes these effects and also include the details of the switch configuration and how that switch time affects the electric field pulse which accelerates the particle beam.
Date: June 15, 2007
Creator: Nelson, S; Poole, B & Caporaso, G
Partner: UNT Libraries Government Documents Department

ELECTROMAGNETIC AND THERMAL SIMULATIONS FOR THE SWITCH REGION OF A COMPACT PROTON ACCELERATOR

Description: A compact proton accelerator for medical applications is being developed at Lawrence Livermore National Laboratory. The accelerator architecture is based on the dielectric wall accelerator (DWA) concept. One critical area to consider is the switch region. Electric field simulations and thermal calculations of the switch area were performed to help determine the operating limits of rmed SiC switches. Different geometries were considered for the field simulation including the shape of the thin Indium solder meniscus between the electrodes and SiC. Electric field simulations were also utilized to demonstrate how the field stress could be reduced. Both transient and steady steady-state thermal simulations were analyzed to find the average power capability of the switches.
Date: June 15, 2007
Creator: Wang, L; Caporaso, G J & Sullivan, J S
Partner: UNT Libraries Government Documents Department

Lattice QCD Thermodynamics First 5000 Trajectories

Description: These results represent the first LQCD analysis for approximately 5000 trajectories with each of the p4rhmc and milc codes, with some of the lower temperature runs having fewer. Both runs were for lattice dimensions of 32{sup 3}x8. Some 32{sup 4} T=0 jobs were also run for p4rhmc. The p4 calculation was performed with v2.0 QMP{_}MPI.X (semi-optimized p4 code using qmp over mpi) and milc version of the su3 rhmc susc eos executable dated Mar 1, 2007 on ubgl in the /usr/gapps/hip/qcd/milc/bin subdirectory (svn revision 28). As with previous runs, calculations were performed along lines of constant physics, with the light quark masses 2-3 times their physics values and the strange quark mass set by m{sub ud} = 0.1m{sub s}. Job submissions were performed using a new subSet.pl job submission script that locates current jobs and submits additional jobs with the same beta value as pending. Note that after reaching a limit of about 35 jobs subsequent submissions are delayed and will not be submitted directly from that state. The job submission script was used to submit revised versions of the milc and p4rhmc csh scripts. Initial thermalized lattices for each code were also for milc (taken from the firstPhys runs), but the p4rhmc runs include thermalization. The only modifications for running on BG/L were to the directory names and the mT parameter which determines job durations (24 hrs on BG/L vs. 4 hrs on ubgl). All finite temperature jobs were submitted to the 512 node partitions, and all T=0 runs were submitted to 2048 node partitions. The set of runs was plagued by filesystem errors on lscratch1 and lscratcH{sub 2}. Many jobs had to be reset (deleting the most recent output file for milc and/or lattice for p4) and resubmitted. The analysis was performed with a new set of scripts ...
Date: March 15, 2007
Creator: Soltz, R & Gupta, R
Partner: UNT Libraries Government Documents Department

LAT Onboard Science: Gamma-Ray Burst Identification

Description: The main goal of the Large Area Telescope (LAT) onboard science program is to provide quick identification and localization of Gamma Ray Bursts (GRB) onboard the LAT for follow-up observations by other observatories. The GRB identification and localization algorithm will provide celestial coordinates with an error region that will be distributed via the Gamma ray burst Coordinate Network (GCN). We present results that show our sensitivity to bursts as characterized using Monte Carlo simulations of the GLAST observatory. We describe and characterize the method of onboard track determination and the GRB identification and localization algorithm. Onboard track determination is considerably different than in the onground case, resulting in a substantially altered point spread function. The algorithm contains tunable parameters which may be adjusted after launch when real bursts characteristics at very high energies have been identified.
Date: October 15, 2007
Creator: Kuhn, Frederick; U., /Ohio State; Bonnell, Jerry; /NASA, Goddard; Hughes, Richard; U., /Ohio State et al.
Partner: UNT Libraries Government Documents Department

Historical Doses from Tritiated Water and Tritiated Hydrogen Gas Released to the Atmosphere from Lawrence Livermore National Laboratory (LLNL). Part 2. LLNL Annual Site-specific Data, 1953 - 2005

Description: Historical information about tritium released routinely and accidentally from all Livermore Site Lawrence Livermore National Laboratory (LLNL) facilities and from the Tritium Research Laboratory of Sandia National Laboratories/California (SNL/CA) between 1953 through 2005 has been compiled and summarized in this report. Facility-specific data (annual release rates and dilution factors) have been derived from the historical information. These facility-specific data are needed to calculate annual doses to a hypothetical site-wide maximally exposed individual from routine releases of tritiated water (HTO) and tritiated hydrogen gas (HT) to the atmosphere. Doses can also be calculated from observed air tritium concentrations, and mean annual values for one air tritium sampling location are presented. Other historical data relevant to a dose reconstruction (e.g., meteorological data, including absolute humidity and rainfall) are also presented. Sources of information are carefully referenced, and assumptions are documented. Uncertainty distributions have been estimated for all parameter values. Confidence in data post-1974 is high.
Date: August 15, 2007
Creator: Peterson, S
Partner: UNT Libraries Government Documents Department

Historical Doses from Tritiated Water and Tritiated Hydrogen Gas Released to the Atmosphere from Lawrence Livermore National Laboratory (LLNL). Part 3. Routine Releases, 1973 - 2005

Description: Annual mean concentrations of tritium in air moisture, calculated from data obtained from an air tritium sampler near the LLNL Discovery Center, were compared with annual mean air moisture concentrations predicted from atmospheric releases of tritium for the years 1973 through 2005. The 95% confidence intervals on the predictions and observations usually overlapped. When the distributions of predictions and observations were different, predictions were higher. Using both the observed and predicted air concentrations as input to the tritium dose model, DCART, annual doses to a hypothetical adult, child (age 10) and infant (age 6 months to 1 year) assumed to be living at LLNL's Discovery Center were calculated. Although the doses based on predicted air concentrations tended to be higher, they were nevertheless indistinguishable from doses based on observed air concentrations when uncertainties were taken into account. Annual doses, calculated by DCART and based on observed and predicted air concentrations, were compared with historical tritium doses reported annually by LLNL. Although the historical doses were calculated using various assumptions over the years, their agreement with the DCART predictions is remarkable. The Discovery Center was not the location of the site-wide maximally exposed individual (SWMEI) from 1974 through 1978. However, doses at the location of the SW-MEI for those years were indistinguishable from those at the Discovery Center when uncertainties were taken into account. The upper confidence limits for all doses were always well below the current regulatory limit for dose to a member of the public (100 {micro}Sv or 10 mrem per year) from atmospheric releases (40 CFR Part 61, Subpart H). Based on observed air concentrations, the 97.5% confidence limit on the cumulative dose to the hypothetical person born in 1973 and living through 2005 at the Discovery Center was 150 {micro}Sv (15 mrem), while that of the hypothetical ...
Date: August 15, 2007
Creator: Peterson, S
Partner: UNT Libraries Government Documents Department

Historical Doses from Tritiated Water and Tritiated Hydrogen Gas Released to the Atmosphere from Lawrence Livermore National Laboratory (LLNL). Part 4. Routine Releases, 1953 - 1972

Description: Lawrence Livermore National Laboratory was founded in September 1952. By 1953, operations involving tritium were underway. Annual doses to an adult, a child (age 10), and an infant (age six months to one year) from tritium released routinely from the Livermore site between 1953 and 1972 were calculated using the tritium dose model, DCART. Uncertainties about sources and release rates are high, particularly for the 1950's, and it was difficult, and sometimes impossible (e.g., when a source was only assumed to have existed) to quantify them accurately. Because of this, every effort was made to assure that the uncertainties applied to the input parameters used in DCART would result in doses that could not have been exceeded. Doses were calculated at the potential locations of the hypothetical site-wide maximally exposed individual (SWMEI), which were at a residence on Vasco Road inside the present west perimeter of the Laboratory (1953 - 1958), at an automotive garage on East Avenue (1961), and at the Discovery Center (1959, 1960, 1962 - 1972, years which predate the facility). Even with the most conservative, screening model assumptions, the highest dose to the SW-MEI (in 1957) was predicted with 95% probability to have been between 27 and 370 {micro}Sv (2.7 and 37 mrem), with the most likely dose being 130 {micro}Sv (13 mrem). Using more realistic, but still conservative assumptions about what fraction of the diet could have been contaminated, these predictions were reduced by more than a factor of two. All other annual doses (at the 97.5% confidence limits) to the SW-MEI, calculated with the most conservative and health protective assumptions, were less than 200 {micro}Sv (20 mrem), and no dose after 1958 could have exceeded 100 {micro}Sv (10 mren). The cumulative dose to the hypothetical individual at the west perimeter location for 1953 through ...
Date: August 15, 2007
Creator: Peterson, S
Partner: UNT Libraries Government Documents Department