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Reconstruction tomography from incomplete projections

Description: In some instances, reconstruction radionuclide tomography must be carried out from projections that do not include projection values for all portions of the object to be reconstructed. This may occur, for example, when the field of view of the detector is limited, or when an opaque foreign body is present within the object. The effects of such incomplete projections upon reconstructions of computer-simulated phantoms were studied, using iterative and convolution methods. Several methods for reducing the resulting artifacts and inaccuracies are discussed. (auth)
Date: January 1, 1975
Creator: Oppenheim, B.E.
Partner: UNT Libraries Government Documents Department

Modification of radiation hazards to the adult and its fetus from nuclear medicine procedures

Description: The effects of perchlorate on the quantitative distribution patterns of / sup 99m/Tc intravenously administered as pertechnetate in the human adult and its fetus were studied in a variety of situations and are summarized. Perchlorate, when administered shortly before /sup 99m/Tc, suppresses concentration in the adult thyroid gland, stomach, and urine; but tends to increase intestinal localization; and prolongs disappearance from the blood. It also inhibits concentration in the placenta and fetus. The greatest reductions in fetal concentrations occur in the femur, spleen, stomach, and thyroid. The estimated radiation absorbed doses to the human fetus are about 80 mrad/mCi for /sup 99m/Tc- pertechnetate alone, and around 30 mrad/mCi if pretreatment with perchlorate is used. Previously localized /sup 99m/Tc may be released by perchlorate from the thyroid gland and stomach, but not from the placenta and fetus. (auth)
Date: January 1, 1976
Creator: Lathrop, K.A.
Partner: UNT Libraries Government Documents Department

Proceedings of the 2010 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

Description: These proceedings contain papers prepared for the Monitoring Research Review 2010: Ground-Based Nuclear Explosion Monitoring Technologies, held 21-23 September, 2010 in Orlando, Florida,. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, National Science Foundation (NSF), Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 21, 2010
Creator: Wetovsky, Marvin A. & Patterson, Eileen F.
Partner: UNT Libraries Government Documents Department

Proceedings of the 2011 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

Description: These proceedings contain papers prepared for the Monitoring Research Review 2011: Ground-Based Nuclear Explosion Monitoring Technologies, held 13-15 September, 2011 in Tucson, Arizona. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), National Science Foundation (NSF), and other invited sponsors. The scientific objectives of the research are to improve the United States' capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 13, 2011
Creator: Wetovsky, Marvin A.; Patterson, Eileen F. & Sandoval, Marisa N.
Partner: UNT Libraries Government Documents Department

Proceedings of the 23rd Seismic Research Symposium: Worldwide Monitoring of Nuclear Explosions

Description: These proceedings contain papers prepared for the 23rd Seismic Research Review: Worldwide Monitoring of Nuclear Explosions, held 2-5 October, 2001 in Jackson Hole, Wyoming. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Technical Applications Center (AFTAC), the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: October 2, 2001
Creator: Warren, N. Jill & Chavez, Francesca C.
Partner: UNT Libraries Government Documents Department

Proceedings of the 21st Seismic Research Symposium: Technologies for Monitoring The Comprehensive Nuclear Test-Ban Treaty

Description: These proceedings contain papers prepared for the 21st Seismic Research Symposium: Technologies for Monitoring The Comprehensive Nuclear-Test-Ban Treaty, held 21-24 September 1999 in Las Vegas, Nevada. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Technical Applications Center (AFTAC), Department of Defense (DoD), the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 21, 1999
Creator: Warren, N. Jill
Partner: UNT Libraries Government Documents Department

Proceedings of the 24th Seismic Research Review: Nuclear Explosion Monitoring: Innovation and Integration

Description: These proceedings contain papers prepared for the 24th Seismic Research Review: Nuclear Explosion Monitoring: Innovation and Integration, held 17-19 September, 2002 in Ponte Vedra Beach, Florida. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 17, 2002
Creator: Warren, N. Jill
Partner: UNT Libraries Government Documents Department

Proceedings of the 25th Seismic Research Review -- Nuclear Explosion Monitoring: Building the Knowledge Base

Description: These proceedings contain papers prepared for the 25th Seismic Research Review -- Nuclear Explosion Monitoring: Building the Knowledge Base, held 23-25 September, 2003 in Tucson, Arizona. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 23, 2003
Creator: Chavez, Francesca C. & Mendius, E. Louise
Partner: UNT Libraries Government Documents Department

Proceedings of the 26th Seismic Research Review: Trends in Nuclear Explosion Monitoring

Description: These proceedings contain papers prepared for the 26th Seismic Research Review: Trends in Nuclear Explosion Monitoring, held 21-23 September, 2004 in Orlando, Florida. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 21, 2004
Creator: Chavez, Francesca C.; Benson, Jody; Hanson, Stephanie; Mark, Carol & Wetovsky, Marvin A.
Partner: UNT Libraries Government Documents Department

Proceedings of the 27th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

Description: These proceedings contain papers prepared for the 27th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 20-22 September, 2005 in Rancho Mirage, California. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 20, 2005
Creator: Wetovsky, Marvin A.; Benson, Jody & Patterson, Eileen F.
Partner: UNT Libraries Government Documents Department

Proceedings of the 28th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

Description: These proceedings contain papers prepared for the 28th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 19-21 September, 2006 in Orlando, Florida. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 19, 2006
Creator: Wetovsky, Marvin A.; Benson, Jody & Patterson, Eileen F.
Partner: UNT Libraries Government Documents Department

Proceedings of the 29th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

Description: These proceedings contain papers prepared for the 29th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 25-27 September, 2007 in Denver, Colorado. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 25, 2007
Creator: Wetovsky, Marvin A.; Benson, Jody & Patterson, Eileen F.
Partner: UNT Libraries Government Documents Department

Proceedings of the 22nd Annual DoD/DOE Seismic Research Symposium: Planning for Verification of and Compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT)

Description: These proceedings contain papers prepared for the 22nd Annual DoD/DOE Seismic Research Symposium: Planning for Verification of and Compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), held 13-15 September 2000 in New Orleans, Louisiana. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Technical Applications Center (AFTAC), Department of Defense (DoD), US Army Space and Missile Defense Command, Defense Special Weapons Agency (DSWA), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 15, 2000
Creator: Nichols, James W., LTC
Partner: UNT Libraries Government Documents Department

The Case for the Application of Worldwide Marine Radioactivity Studies In the Search for Undeclared Facilities and Activities

Description: Undeclared nuclear facilities unequivocally remain the most difficult safeguards challenge facing the International Atomic Energy Agency (IAEA). Recent cases of undeclared facilities revealed in Iran and Syria, which are NPT signatory States, show both the difficulty and the seriousness of this threat to nonproliferation. In the case of undeclared nuclear facilities, the most effective deterrent against proliferation is the application of Wide-Area Environmental Sampling (WAES); however, WAES is currently cost-prohibitive. As with any threat, the most effective countering strategy is a multifaceted approach. Some of the approaches applied by the IAEA include: open source analysis, satellite imagery, on-site environmental sampling, complementary access under the Additional Protocol (where in force), traditional safeguards inspections, and information provided by member States. These approaches, naturally, are focused on specific States. Are there other opportunities not currently within the IAEA purview to assess States that may provide another opportunity to detect clandestine facilities? In this paper, the author will make the case that the IAEA Department of Safeguards should explore the area of worldwide marine radioactivity studies as one possible opportunity. One such study was released by the IAEA Marine Environment Laboratory in January 2005. This technical document focused on 90Sr, 137Cs, and 239/240Pu. It is clearly a challenging area because of the many sources of anthropogenic radionuclides in the world’s oceans and seas including: nuclear weapons testing, reprocessing, accidents, waste dumping, and industrial and medical radioisotopes, whose distributions change based on oceanographic, geochemical, and biological processes, and their sources. It is additionally challenging where multiple States share oceans, seas, and rivers. But with the application of modern science, historical sampling to establish baselines, and a focus on the most relevant radionuclides, the potential is there to support this challenging IAEA safeguards mission.
Date: June 1, 2013
Creator: Schanfein, Mark
Partner: UNT Libraries Government Documents Department

Entombment: It is Time to Reconsider this Technology

Description: It is time to reconsider entombment of nuclear reactors and other facilities. Decommissioning worker exposure and safety, transportation, cost, potential loss of LLW disposal capacity, and need for strong technical basis are shared drivers for the renewed interest in developing the entombment D&D option. Entombment relies on retarding the release of radionuclides for a very long period, a number of factors must be considered prior to selection and implementation of entombment. A technical basis for addressing and evaluating these factors with associated stakeholder acceptance of the technology is needed before entombment becomes an accepted D&D option.
Date: September 1, 2000
Creator: Birk, Sandra Margaret; Hanson, Robert Gail & Vernon, Donald Keith
Partner: UNT Libraries Government Documents Department

Early progress of the Biomedical Computing Technology Information Center (BCTIC)

Description: Through five years of effort by the Society of Nuclear Medicine Computer Committee, the Biomedical Computing Technology Information Center (BCTIC) was established by the Division of Biomedical and Environmental Research (DBER) of the U. S. Energy Research and Development Administration (ERDA) at the Oak Ridge National Laboratory in July of 1975. BCTIC forged ahead into the tasks of designing guidelines and procedures, acquisition and packaging of computer codes, data, and interface designs; building a bibliographic data base; and maintaining a directory of the user community. Important contacts were made with societies and individuals involved in biomedical computing; and BCTIC was publicized through news releases, the BCTIC newsletter (bimonthly, since October, 1975), presentations at meetings, and personal contacts. This paper presents the response BCTIC has received in its initial months, gives a progress report on the developmental phase, and takes a look to the future of BCTIC as a national technology resource in nuclear medicine computing. (auth)
Date: January 1, 1976
Creator: Maskewitz, B.F.; Henne, R.L. & McClain, W.J.
Partner: UNT Libraries Government Documents Department

Non-linear image processing

Description: Processing of nuclear medicine images is generally performed by essentially linear methods with the non-negativity condition being applied as the only non-linear process. The various methods used: matrix methods in signal space and Fourier or Hadamard transforms in frequency or sequency space are essentially equivalent. Further improvement in images can be obtained by the use of inherently non-linear methods. The recent development of an approximation to a least-difference method (as opposed to a least-square method) has led to an appreciation of the effects of data bounding and to the development of a more powerful process. Data bounding (modification of statistically improbable data values) is an inherently non-linear method with considerable promise. Strong bounding depending on two-dimensional least-squares fitting yields a reduction of mottling (buttermilk effect) not attainable with linear processes. A pre- bounding process removing very bad points is used to protect the strong bounding process from incorrectly modifying data points due to the weight of an extreme but yet unbounded point as the fitting area approaches it. (auth)
Date: January 1, 1976
Creator: Bell, P.R.; Dillon, R.S. & Bell, M.R.
Partner: UNT Libraries Government Documents Department

Proceedings of the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring

Description: These proceedings contain papers prepared for the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 23-25 September, 2008 in Portsmouth, Virginia. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States’ capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 23, 2008
Creator: Wetovsky, Marv A; Aguilar-chang, Julio; Arrowsmith, Marie; Arrowsmith, Stephen; Baker, Diane; Begnaud, Michael et al.
Partner: UNT Libraries Government Documents Department

National Low-Level Waste Management Program Radionuclide Report Series

Description: The National Low Level Waste Management Program at the Idaho National Engineering and Environmental Laboratory has published a report containing key information about selected radionuclides that are most likely to contribute significantly to the radiation exposures estimated from a performance assessment of a low-level radioactive waste (LLW) disposal facility. The information includes physical and chemical characteristics, production means, waste forms, behavior of the radionuclide in soils, plants, groundwater, and air, and biological effects in animals and humans. The radionuclides included in this study comprise all of the nuclides specifically listed in 10CFR61.55, Tables 1 and 2, 3 H, 14 C, 59 Ni, 60 Co, 63 Ni, 90 Sr, 94 Nb, 99 Tc, 129 I, 137 Cs, 241 Pu, and 242 Cm. Other key radionuclides addressed in the report include 237 Np, 238 U, 239 Pu, and 241 Am. This paper summarizes key information contained within this report.
Date: March 1, 1999
Creator: Adams, James Paul; Carboneau, Michael Leonard & Allred, William Edgar
Partner: UNT Libraries Government Documents Department

Distilling Complex Model Results into Simple Models for use in Assessing Compliance with Performance Standards for Low Level Waste Disposal Facilities

Description: Assessing the long term performance of waste disposal facility requires numerical simulation of saturated and unsaturated groundwater flow and contaminant transport. Complex numerical models have been developed to try to realistically simulate subsurface flow and transport processes. These models provide important information about system behavior and identify important processes, but may not be practical for demonstrating compliance with performance standards because of excessively long computer simulation times and input requirements. Two approaches to distilling the behavior of a complex model into simpler formulations that are practical for demonstrating compliance with performance objectives are examined in this paper. The first approach uses the information obtained from the complex model to develop a simple model that mimics the complex model behavior for stated performance objectives. The simple model may need to include essential processes that are important to assessing performance, such as time-variable infiltration and waste emplacement rates, subsurface heterogeneity, sorption, decay, and radioactive ingrowth. The approach was applied to a Low-Level Waste disposal site at the Idaho National Laboratory where a complex three dimensional vadose zone model was developed first to understand system behavior and important processes. The complex model was distilled down to a relatively simple one-dimensional vadose zone model and three-dimensional aquifer transport model. Comparisons between the simple model and complex model of vadose zone fluxes and groundwater concentrations showed relatively good agreement between the models for both fission and activation products (129I, 36Cl, 99Tc) and actinides (238U, 239Pu, 237Np). Application of the simple model allowed for Monte Carlo uncertainty analysis and simulations of numerous disposal and release scenarios. The second approach investigated was the response surface model. In the response surface model approach, the temporal response of a complex model to an instantaneously-released unit mass of a conservative tracer at a defined point is calculated and stored (the ...
Date: February 1, 2007
Creator: Rood, Arthur S.
Partner: UNT Libraries Government Documents Department

Evaluating the Dose Consequences of Progeny Ingrowth and Decay During Transport in the Environment - Counting Atoms

Description: The evaluation of a release of radioactive material to the environment is a complex problem. The evaluation of the dose consequences from such a release adds issues that must be considered in order to determine the actual radiation dose to an individual. One of the key issues is the ingrowth of the progeny from the initial inventory during the transport through the environment. The evaluation of an acute release from a criticality accident and a chronic release of transuranics to the soil are the two extremes that demonstrate the spectrum of issues that must be addressed in order to determine the dose to a receptor at some distance and time from the release point. The evaluation of this can be accomplished by integration of the buildup and decay differential equations. The differential equations are difficult to evaluate for a source term that contains numerous short-lived radionuclides in decay chains. The evaluation is simplified by a method of evaluation called "counting atom". The source term is evaluated on an atom basis during production and transport. The life cycle of the atoms of each radionuclide are evaluated individually from the generation during a criticality event and during transport through the facility and environment to the downwind receptor.
Date: April 1, 2002
Creator: Schrader, Bradley J & Wenzel, D. R.
Partner: UNT Libraries Government Documents Department

Clinical $sup 13$CO$sub 2$ breath tests: methodology and limitations

Description: Methods were developed to perform $sup 13$CO$sub 2$ breath tests and the limitations and sources of error in these tests were explored. The random error introduced during each step of the analysis was determined and it was found that the precision was limited by the fluctuations in the isotope ratio of the patient's endogenous CO$sub 2$. The detection limit was a 1.4 percent increase in the isotope ratio. This corresponds to an oxidation rate of 140 nmoles/kg-hr of singly labeled substrate to CO$sub 2$. The use of stable isotope $sup 13$C provides a safe and sensitive alternative to the use of the radionuclide $sup 14$C and extends the utility of CO$sub 2$ breath tests to the previously exempted populations of children and pregnant women. (auth)
Date: January 1, 1975
Creator: Schoeller, D.A.; Klein, P.D.; Schneider, J.F.; Solomons, N.W. & Watkins, J.B.
Partner: UNT Libraries Government Documents Department

14'' x 17'' film recorder for computer-enhanced scans

Description: Physician acceptance of computer-enhanced radionuclide scan results, presented in the form of small Polaroid pictures, has been very limited for a number of subjective reasons. A new recorder was designed and constructed that presents the results of computer augmented scans through a medium that is quite familiar to doctors, the standard 14 in. x 17 in. x-ray film. (auth)
Date: January 1, 1976
Creator: Morris, A. C., Jr.; Barclay, T. R.; Akin, T. E.; Hansard, M. C.; Gibbs, W. D. & Modzelewski, C. U.
Partner: UNT Libraries Government Documents Department