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X-RAY DOSAGE TO PATIENTS UNDERGOING ORAL ROENTGEN-OGRAPHY

Description: This report endeavors to point out the radiation hazards involved with respect to the patient undergoing oral roentgenography. The dose rate can be as high as 280 r/min. Very definite hematological changes have been observed and are being thoroughly investigated. Recommendations have been suggested to eliminate overexposures.
Date: July 16, 1952
Creator: Nolan, W. E.
Partner: UNT Libraries Government Documents Department

Basis for dose rate to curie assay method

Description: Disposition of low-level solid waste packages at the Hanford Site requires quantifying the radioactive contents of each container. This study generated conversion factors to apply to the results of contact surveys that are performed with standard dose rate survey instruments by field health physics technicians. This study determined the accuracy of this method, and identified the major sources of uncertainty. It is concluded that the dominant error is associated with the possibility that the radioactive source is not homogeneously distributed.
Date: October 31, 1996
Creator: Gedeon, S.R.
Partner: UNT Libraries Government Documents Department

SATIF-2 shielding aspects of accelerators, targets and irradiation facilities

Description: Particle accelerators have evolved over the last 50 years from simple devices to powerful machines, and will continue to have an important impact on research, technology and lifestyle. Today they cover a wide range of applications, from television and computer displays in households to the investigation of the origin and structure of matter. It has become common practice to use them for material science and medical applications. In recent years, requirements from new technological and research applications have emerged, such as increased particle beams intensities, higher flexibility, etc., giving rise to new radiation shielding aspects and problems. These proceedings review recent progress in radiation shielding of accelerator facilities, and evaluate advancements with respect to international co-operation in this field.
Date: December 31, 1995
Partner: UNT Libraries Government Documents Department

Dose enhancement in a room cobalt-60 source

Description: A room Co-60 source was characterized using TLDs and pMOS RADFETs. Dose enhancement was measured using RADFETs with and without gold- flashed kovar lids. A methodology was developed to predict dose enhancement vs position and test configuration.
Date: June 1, 1997
Creator: Simons, M.; Pease, R.L.; Fleetwood, D.M.; Schwank, J.R. & Krzesniak, M.
Partner: UNT Libraries Government Documents Department

Inspection and Gamma-Ray Dose Rate Measurements of the Annulus of the VSC-17 Concrete Spent Nuclear Fuel Storage Cask

Description: The air cooling annulus of the Ventilated Storage Cask (VSC)-17 spent fuel storage cask was inspected using a Toshiba 7 mm (1/4”) CCD video camera. The dose rates observed in the annular space were measured to provide a reference for the activity to which the camera(s) being tested were being exposed. No gross degradation, pitting, or general corrosion was observed.
Date: September 1, 2007
Creator: Winston, P. L.
Partner: UNT Libraries Government Documents Department

PLANNING TOOLS FOR ESTIMATING RADIATION EXPOSURE AT THE NATIONAL IGNITION FACILITY

Description: A set of computational tools was developed to help estimate and minimize potential radiation exposure to workers from material activation in the National Ignition Facility (NIF). AAMI (Automated ALARA-MCNP Interface) provides an efficient, automated mechanism to perform the series of calculations required to create dose rate maps for the entire facility with minimal manual user input. NEET (NIF Exposure Estimation Tool) is a web application that combines the information computed by AAMI with a given shot schedule to compute and display the dose rate maps as a function of time. AAMI and NEET are currently used as work planning tools to determine stay-out times for workers following a given shot or set of shots, and to help in estimating integrated doses associated with performing various maintenance activities inside the target bay. Dose rate maps of the target bay were generated following a low-yield 10{sup 16} D-T shot and will be presented in this paper.
Date: October 22, 2010
Creator: Verbeke, J; Young, M; Brereton, S; Dauffy, L; Hall, J; Hansen, L et al.
Partner: UNT Libraries Government Documents Department

Measurements of prompt radiation induced conductivity of Kapton.

Description: We performed measurements of the prompt radiation induced conductivity in thin samples of Kapton (polyimide) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil samples were irradiated with a 0.5 {mu}s pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E10 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Analysis rendered prompt conductivity coefficients between 6E-17 and 2E-16 mhos/m per rad/s, depending on the dose rate and the pulse width.
Date: October 1, 2010
Creator: Preston, Eric F. (ITT Corporation, Colorado Springs, CO); Zarick, Thomas Andrew; Sheridan, Timothy J.; Hartman, E. Frederick & Stringer, Thomas Arthur (ITT Corporation, Colorado Springs, CO)
Partner: UNT Libraries Government Documents Department

POST-SHOT RADIATION ENVIRONMENT FOLLOWING LOW-YIELD SHOTS INSIDE THE NATIONAL IGNITION FACILITY

Description: A detailed model of the Target Bay (TB) at the National Ignition Facility (NIF) has been developed to estimate the post-shot radiation environment inside the facility. The model includes large number of structures and diagnostic instruments present inside the TB. These structures and instruments are activated by the few nanosecond pulse of neutrons generated during a shot and the resultant gamma dose rates are estimated at various decay times following the shot. The results presented in this paper are based on a low-yield D-T shot of 10{sup 16} neutrons. General environment dose rates drop to below 3 mrem/h within three hours following a shot with higher dose rates observed at contact with some of the components. Dose rate maps of the different TB levels were generated to aid in estimating worker stay-out times following a shot before entry is permitted into the TB.
Date: October 29, 2010
Creator: Sitaraman, S; Brereton, S; Dauffy, L; Hall, J; Hansen, L; Khater, H et al.
Partner: UNT Libraries Government Documents Department

Estimated effective dose rates from radon exposure in workplaces and residences within Los Alamos county in New Mexico

Description: Many millions of office workers are exposed to radon while at work and at home. Though there has been a multitude of studies reporting the measurements of radon concentrations and potential lung and effective doses associated with radon and progeny exposure in homes, similar studies on the concentrations and subsequent effective dose rates in the workplace are lacking. The purposes of this study were to measure radon concentrations in office and residential spaces in the same county and explore the radiation dose implications. Sixty-five track-etch detectors were deployed in office spaces and 47 were deployed in residences, all within Los Alamos County, New Mexico, USA. The sampling periods for these measurements were generally about three months. The measured concentrations were then used to calculate and compare effective dose rates resulting from exposure while at work and at home. Results showed that full-time office workers receive on average about nine times greater exposure at home than while in the office (691 mrem yr{sup -1} versus 78 mrem yr{sup -1}). The estimated effective dose rate for a more homebound person was 896 mrem yr{sup -1}. These effective dose rates are contrasted against the 100 mrem yr{sup -1} threshold for regulation of a 'radiological worker' defined in the Department of Energy regulations occupational exposure and the 10 mrem yr{sup -1} air pathway effective public dose limit regulated by the Environmental Protection Agency.
Date: January 1, 2009
Creator: Whicker, Jeffrey J & Mcnaughton, Michael
Partner: UNT Libraries Government Documents Department

Work to save dose: contrasting effective dose rates from radon exposure in workplaces and residences against the backdrop of public and occupational limits

Description: Office workers are exposed to radon while at work and at home. Though there has been a multitude of studies reporting the measurements of radon concentrations and potential lung and effective doses associated with radon and progeny exposure in homes, similar studies on the concentrations and subsequent effective dose rates in the non-mine workplaces are lacking. Additionally, there are few, if any, comparative analyses of radon exposures at more 'typical' workplace with residential exposures within the same county. The purposes of this study were to measure radon concentrations in office and residential spaces in the same county and explore the radiation dose implications. Sixty-five track-etch detectors were deployed in office spaces and 47 were deployed in residences, all within Los Alamos County, New Mexico, USA. The sampling periods for these measurements were generally about three months. The measured concentrations were used to calculate and compare effective dose rates resulting from exposure while at work and at home. Results showed that full-time office workers receive on average about 8 times greater exposure at home than while in the office (2.3 mSv yr-! versus 0.3 mSv yr-!). The estimated effective dose rate for a more homebound person was about 3 mSv yr-!. Estimating effective doses from background radon exposure in the same county as Los Alamos National Laboratory, with thousands of'radiological workers,' highlights interesting contrasts in radiation protection standards that span public and occupational settings. For example, the effective dose rate from background radon exposure in unregulated office spaces ranged up to 1.1 mSv yr-!, which is similar to the 1 mSv yr-! threshold for regulation ofa 'radiological worker,' as defined in the Department of Energy regulations for occupational exposure. Additionally, the estimated average effective dose total of> 3 mSv yf! from radon background exposure in homes stands in contrast to the ...
Date: January 1, 2009
Creator: Whicker, Jeffrey J & Mcnaughton, Michael W
Partner: UNT Libraries Government Documents Department

A Radiation shielding study for the Fermilab Linac

Description: Radiation shielding calculations are performed for the Fermilab Linac enclosure and gallery. The predicted dose rates around the access labyrinth at normal operation and a comparison to measured dose rates are presented. An accident scenario is considered as well.
Date: February 1, 2006
Creator: Rakhno, I. & Johnstone, C.
Partner: UNT Libraries Government Documents Department

Evaluation of Proposed New LLW Disposal Activity Disposal of No Dose/Low Dose Scrap Metal in Slit Trenches

Description: Activated metal is a special waste that requires evaluation for disposal. Contaminants in the activated metal will leach more slowly than will contaminants in generic waste. There is an inventory of activated scrap metal in the 105-L Disassembly Basin. Approximately 1,600 ft3 of the material is characterized as ''No Dose/Low Dose'' and consists mainly of activated aluminum and aluminum alloy pieces and parts and no stainless steel with a dose rate less than 200 mR per hr. Contaminants in the activated metal will leach more slowly than will contaminants in generic waste. The change in the leach rate will affect analyses for the groundwater pathway and intruder scenarios. For this evaluation, the slower leach rate from the activated metal waste will be neglected for the groundwater pathway, which is conservative because the higher leach rate used tends to produce higher groundwater concentrations and lower inventory limits. For this evaluation, the leach rate was set to zero for intruder scenarios, which is conservative for the inadvertent intruder because a slower leach rate will result in higher levels of radionuclides in the waste zone. The evaluation concludes that the existing limits are applicable to the disposal of No Dose/Low Dose activated scrap metal in slit trenches so that a Special Analysis is not needed to dispose of this waste stream.
Date: February 11, 2004
Creator: Cook, JR
Partner: UNT Libraries Government Documents Department

Diagnostic modeling for real-time emergency response

Description: The Atmospheric Release Advisory Capability (ARAC) provides real-time dose assessments for airborne pollutant releases. ARAC is currently in the process of developing an entirely new suite of models and system infrastructure. Diagnostic and dispersion algorithms are being created in-house and a prognostic model NO-RAPS, imported from the Naval Research Laboratory, Monterey, is currently being adapted to ARAC`s needs. Diagnostic models are essential for an emergency response capability since they provide the ability to rapidly assimilate available meteorological data and generate the mass-consistent three-dimensional wind fields required by dispersion models. The resulting wind fields may also serve to initialize and validate prognostic models. In general, the performance of diagnostic models strongly correlates with the density and distribution of measurements in the area of interest and the resolution of the terrain. problem, data can be extracted from user-specified databases within a region defined by a metdata grid. Typically the data collection region will cover a geographic domain significantly larger than the area involved in the dispersion simulation in order to provide the most complete set of meteorological information relevant to the problem. This also permits the user to redefine the problem grid size and location, within limits, without reaccessing the meteorological data extraction system. After the data has been collected, an associated meteorological preprocessor places it in a standard form for further processing. The pre-processor does not alter or interpolate wind values; it only performs reversible transformations to convert the data to a standard unambiguous form, e.g. latitude, longitude, height, wind speed and direction. This allows the diagnostic models to use a generalized data ingest routine, not dependent on the form or format of the meteorological data source or database.
Date: September 7, 1995
Creator: Sugiyama, G.; Rodriguez, D. & Lee, R.
Partner: UNT Libraries Government Documents Department

BUSFET - A Novel Radiation-Hardened SOI Transistor

Description: A partially-depleted SOI transistor structure has been designed that does not require the use of specially-processed hardened buried oxides for total-dose hardness and maintains the intrinsic SEU and dose rate hardness advantages of SOI technology.
Date: February 4, 1999
Creator: Dodd, P.E.; Draper, B.L.; Schwank, J.R. & Shaneyfelt, M.R.
Partner: UNT Libraries Government Documents Department

Radionuclide mass inventory, activity, decay heat, and dose rate parametric data for TRIGA spent nuclear fuels

Description: Parametric burnup calculations are performed to estimate radionuclide isotopic mass and activity concentrations for four different Training, Research, and Isotope General Atomics (TRIGA) nuclear reactor fuel element types: (1) Aluminum-clad standard, (2) Stainless Steel-clad standard, (3) High-enrichment Fuel Life Improvement Program (FLIP), and (4) Low-enrichment Fuel Life Improvement Program (FLIP-LEU-1). Parametric activity data are tabulated for 145 important radionuclides that can be used to generate gamma-ray emission source terms or provide mass quantity estimates as a function of decay time. Fuel element decay heats and dose rates are also presented parametrically as a function of burnup and decay time. Dose rates are given at the fuel element midplane for contact, 3.0-feet, and 3.0-meter detector locations in air. The data herein are estimates based on specially derived Beginning-of-Life (BOL) neutron cross sections using geometrically-explicit TRIGA reactor core models. The calculated parametric data should represent good estimates relative to actual values, although no experimental data were available for direct comparison and validation. However, because the cross sections were not updated as a function of burnup, the actinide concentrations may deviate from the actual values at the higher burnups.
Date: March 1, 1997
Creator: Sterbentz, J.W.
Partner: UNT Libraries Government Documents Department

Calculated dose rates in halls using CASIM

Description: The first part of this document shows the results of a series of CASIM runs designed to optimize the size of a steel cylinder so as to produce the highest density of stars at any given radius perpendicular to beam direction. For the next set of runs the length of the cylinder is now fixed at three meters and the authors vary the radius. These runs show that a cylinder with a radius of seven centimeters produces the highest dose rate. For the rest of the CASIM runs a cylinder three meters long with a radius of seven centimeters will be used. Using the optimized cylinder they now make runs using geometries more closely representing real experimental hall geometries in an attempt to predict possibly dose rates.
Date: February 1, 1995
Creator: Sondgeroth, A.
Partner: UNT Libraries Government Documents Department