Physics Commons^™

Development Of Dose Coefficients For Radionulides Produced In Spallation Neutron Sources: Annual Report, Phillip W. Patton, Mark Rudin

Transmutation Sciences Physics (TRP)

The University of Nevada, Las Vegas (UNLV) Transmutation Research Program has been tasked to support U.S. Department of Energy (DOE) efforts to assess the health risks associated with the operation of each of their accelerator-driven nuclear facilities for both NEPA and PSAR development. Quantifying the radiological risks to workers will have to be addressed during the design and siting of each of these facilities. U.S. Environmental Protection Agency (EPA) Federal Guidance Report No. 11 “Limiting Values of Intake and Air Concentration and Dose Conversion Factors for Inhalation, Submersion, and Ingestion”, developed two derived guides, Annual Limit on Intake (ALI) and …

Development Of Dose Coefficients For Radionuclides Produced In Spallation Targets, Phillip W. Patton, Mark Rudin

Transmutation Sciences Physics (TRP)

Dose coefficients permit simple determination of radiation dose associated with various exposure scenarios, and ultimately permit radiation safety personnel to assess the health risks to workers in a nuclear facility. Specifically, radiation safety personnel use dose coefficients to determine the radiation dose incurred to a tissue or organ system from a given exposure. These parameters are often expressed in terms of Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs).

Results from this study will be used to produce ALIs and DACs for these rare radionuclides created by spallation target systems that are not included in Federal Guidance Report …

Dose Coefficient (Dc) Methodology Report, John P. Shanahan, Phillip W. Patton, Mark Rudin

Transmutation Sciences Physics (TRP)

The purpose of this report is to present the methodology developed to calculate internal and external dose coefficients for radionuclides produced in the spallation process. Much of the information regarding computer codes in this report comes from various technical manuals and professional papers. References are provided at the beginning of each section for documentation and for the user who requires more specific information. The report also includes the results of applying the methodology to determine dose coefficients for five radionuclides. This effort identified potential areas of concern that will need to be addressed when the methodology is used in the …

Development Of Dose Coefficients For Radionuclides Produced In Spallation Neutron Sources, Phillip W. Patton

Transmutation Sciences Physics (TRP)

A research consortium comprised of representatives from several universities and national laboratories has been established as part of this on-going project to generate internal and external dose conversion coefficients for radionuclides produced in spallation neutron sources. Information obtained from this multi-year study will be used to support the siting and licensing of future accelerator-driven nuclear initiatives within the U.S. Department of Energy complex, including the Spallation Neutron Source (SNS) and Accelerator Production of Tritium (APT) Projects. Determination of these coefficients will also fill data gaps for several hundred radionuclides that exist in Federal Guide Report No. 11 and in Publications …

Residential Radon Exposure And Lung Cancer: Variation In Risk Estimates Using Alternative Exposure Scenarios, R. William Field, Brian J. Smith, Daniel J. Steck, Charles F. Lynch

Physics Faculty Publications

The most direct way to derive risk estimates for residential radon progeny exposure is through epidemiologic studies that examine the association between residential radon exposure and lung cancer. However, the National Research Council concluded that the inconsistency among prior residential radon case-control studies was largely a consequence of errors in radon dosimetry. This paper examines the impact of applying various epidemiologic dosimetry models for radon exposure assessment using a common data set from the Iowa Radon Lung Cancer Study (IRLCS). The IRLCS uniquely combined enhanced dosimetric techniques, individual mobility assessment, and expert histologic review to examine the relationship between cumulative …

Development Of Dose Coefficients For Radionulides Produced In Spallation Neutron Sources: Annual Report, Phillip W. Patton, Mark Rudin

Transmutation Sciences Physics (TRP)

The University of Nevada, Las Vegas (UNLV) Transmutation Research Program has been tasked to support U.S. Department of Energy (DOE) efforts to assess the health risks associated with the operation of each of their accelerator-driven nuclear facilities for both NEPA and PSAR development. Quantifying the radiological risks to workers will have to be addressed during the design and siting of each of these facilities. U.S. Environmental Protection Agency (EPA) Federal Guidance Report No. 11 “Limiting Values of Intake and Air Concentration and Dose Conversion Factors for Inhalation, Submersion, and Ingestion”, developed two derived guides, Annual Limit on Intake (ALI) and …

Development Of Dose Conversion Coefficients For Radionuclides Produced In Spallation Neutron Sources, Phillip W. Patton, Mark Rudin

Transmutation Sciences Physics (TRP)

For the first year of this effort, the UNLV research team set out four objectives. First, the university and laboratory consortium had to be established. This consortium was tasked with helping to determine the methodology for determining the dose coefficients, and to ensure that the resulting DCs will be of use to the national programs developing accelerator-driven nuclear systems (such as the SNS or an accelerator-driven transmutation system) and to the health physics community as a whole. The second goal of this program was to determine a methodology and then prioritize the radionuclides so that the research effort would address …

Intercomparison Of Retrospective Radon Detectors, R. William Field, Daniel J. Steck, Mary Ann Parkhurst, Judy A. Mahaffey, Michael C.R. Alavanja

Physics Faculty Publications

We performed both a laboratory and a field intercomparison of two novel glass-based retrospective radon detectors previously used in major radon case-control studies performed in Missouri and Iowa. The new detectors estimate retrospective residential radon exposure from the accumulation of a long-lived radon decay product, ²¹⁰Pb, in glass. The detectors use track registration material in direct contact with glass surfaces to measure the α-emission of a ²¹⁰Pb-decay product, ²¹⁰Po. The detector's track density generation rate (tracks per square centimeter per hour) is proportional to the surface α-activity. In the absence of other strong sources of α-emission in …

Exposure To Atmospheric Radon, Daniel J. Steck, R. William Field, Charles F. Lynch

Physics Faculty Publications

We measured radon (²²²Rn) concentrations in Iowa and Minnesota and found that unusually high annual average radon concentrations occur outdoors in portions of central North America. In some areas, outdoor concentrations exceed the national average indoor radon concentration. The general spatial patterns of outdoor radon and indoor radon are similar to the spatial distribution of radon progeny in the soil. Outdoor radon exposure in this region can be a substantial fraction of an individual's total radon exposure and is highly variable across the population. Estimated lifetime effective dose equivalents for the women participants in a radon-related lung cancer …

Residential Radon-222 Exposure And Lung Cancer: Exposure Assessment Methodology, R. William Field, Daniel J. Steck, Charles F. Lynch, Christine P. Brus, John S. Neuberger, Burton C. Kross

Physics Faculty Publications

Although occupational epidemiological studies and animal experimentation provide strong evidence that radon-222 (²²²Rn) progeny exposure causes lung cancer, residential epidemiological studies have not confirmed this association. Past residential epidemiological studies have yielded contradictory findings. Exposure misclassification has seriously compromised the ability of these studies to detect whether an association exists between ²²²Rn exposure and lung cancer. Misclassification of ²²²Rn exposure has arisen primarily from: 1) detector measurement error; 2) failure to consider temporal and spatial ²²²Rn variations within a home; 3) missing data from previously occupied homes that currently are inaccessible; 4) failure to link …

Optical Properties Of Human Uterus At 630 Nm, Steen J. Madsen, Bruce J. Tromberg, Yona Tadir, Pius Wyss, Lars O. Svaasand, Richard C. Haskell

All HMC Faculty Publications and Research

The optical properties of normal and fibriotic human uteri were determined using frequency-domain and steady-state techniques .

Measuring Airborne Alpha Radioactivity, Greg Taft

Honors Theses, 1963-2015

This project develops alpha spectroscopy to measure the airborne concentrations of attached and unattached radon progeny. The system is designed and constructed to be used in homes, thus is portable, fast, and easy to use.

The Wavelength Dependence Of Herpes Simplex Viral Inactivation & Ultraviolet Enhanced Reactivation, Richard Detsch

Masters Theses & Specialist Projects

The degrees of Ultraviolet Enhanced Reactivation (UVR) by mammalian cells of Heroes simplex virus inactivated by different wavelengths of far ultraviolet radiation were measure'. The wavelength dependence of UVR is presented for the wavelength region 238 nm to 297 nm. The shape of the UVR curve suggests that virus directed repair is less dependent on the wavelength of UV radiation than are cellular repair mechanisms. The wavelength dependence of Herpes simplex inactivation by far UV radiation is also presented. The shape of the virus inactivation curve suggests the involvement of both DNA and protein.