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Taxonomic and developmental aspects of radiosensitivity

Description: Considerable information is available on the effects of radioactivity on adult and early life stages of organisms. The preponderance of data is on mortality after a single irradiation with relatively high doses. Unfortunately, because experiments were carried out under different conditions and for different time periods, the validity of comparing the results from different laxonomic groups is questionable. In general, the conclusions are that there is a relationship (1) between radioresistance to high doses of acute radiation and taxonomy of the organism, primitive forms being more radioresistant than complex vertebrates and (2) between radiosensitivity and developmental stage, early life stages being more sensitive than later stages. The first conclusion may be related to the capability of the organism to repopulate cells and to differentiate and redifferentiate them; the second to the rate of cellular division and to the degree of differentiation. In question, however, is the relevance of the responses from high levels of acute radiation to that of the responses to long-term exposure to low levels of radiation, which are ecologically of more interest. Data from studies of the effects of acute and chronic exposure on development of gametes and zygotes indicate that, for some fishes and invertebrates, responses at the cellular and molecular levels show effect levels comparable to those observed in some mammals. Acute doses between 0,05 and 0.5Cy and dose rates between 0.02 to 0.2mCy/h appear to define critical ranges in which detrimental effects on fertility are first observed in a variety of radiosensitive organisms. To better understand inherent radiosensitivity, we need more information on the ability of cells to repopulate and differentiate and to prevent or repair damage to biological critical molecules, such as DNA, because these factors may alter significantly organisms` responses to radiation.
Date: November 1, 1996
Creator: Harrison, F.L. & Anderson, S.L.
Partner: UNT Libraries Government Documents Department

Tritium stripping in a nitrogen glove box using palladium/zeolite and SAES St 198{trademark}

Description: Glove box clean-up experiments were conducted in a nitrogen glove box using palladium deposited on zeolite (Pd/z) and a SAES St 198{trademark} getter as tritium stripping materials. Protium/deuterium samples spiked with tritium were released into a 620 liter glove box to simulate tritium releases in a 10,500 liter glove box. The Pd/z and the SAES St 198{trademark} stripper beds produced a reduction in tritium activity of approximately two to three orders of magnitude and glove box clean-up was limited by a persistent background tritium activity level. Attempts to significantly reduce the glove box activity to lower levels without purging were unsuccessful.
Date: January 1, 1995
Creator: Klien, J.E. & Wermer, J.R.
Partner: UNT Libraries Government Documents Department

Rhenium Radioisotopes for Therapeutic Radiopharmaceutical Development

Description: The availability of therapeutic radioisotopes at reasonable costs is important for applications in nuclear medicine, oncology and interventional cardiology, Rhenium-186 (Re-186) and rhenium-1 88 (Re-188) are two reactor-produced radioisotope which are attractive for a variety of therapeutic applications, Rhenium-186 has a half-life of 90 hours and decays with emission of a &particle with a maximum energy of 1.08 MeV and a 135 keV (9Yo) gamma which permits imaging. In contrast, Re- 188 has a much shorter half-life of 16.9 hours and emits a p-particle with a much higher energy of 2.12 MeV (Em=) and a 155 keV gamma photon (15Yo) for imaging. While Re-186 is unavailable from a generator system and must be directly produced in a nuclear reactor, Re-188 can also be directly produced in a reactor with high specific activity, but is more conveniently and cost-effectively available as carrier-free sodium perrhenate by saline elution of the alumina-based tungsten-188 (W1 88)/Re-l 88 generator system [1-2]. Since a comprehensive overviewofRe-186 and Re-188 therapeutic agents is beyond the scope of this &tended Abstrac4 the goal is to provide key examples of various agents currently in clinical use and those which are being developed for important clinical applications.
Date: January 18, 1999
Creator: Beets, A.L.; Knapp, F.F., Jr.; Kropp, J.; Lin, W.-Y.; Pinkert, J. & Wang, S.-Y.
Partner: UNT Libraries Government Documents Department

Application of Ultrasonic Techniques for Brain Injury Diagnosis

Description: In this work, we evaluate methods for detecting brain injury using ultrasound. We have used simulations of ultrasonic fields in the head to model the phase distortion of the skull. In addition we present experimental data from the crania of large animals. The experimental data help us understand and evaluate the performance of different transducers in acquiring the backscatter data from the brain through the skull. Both the simulations and acquired data illustrate the superiority of lower-frequency (<= 1 MHz) ultrasonic fields for transcranial acquisition of signals from inside the brain. Additionally, the experimental work shows that the higher-frequency (5 MHz) ultrasound can also be useful in acquiring clean nearfield data to help detect the position of the inner boundary of the skull.
Date: September 19, 1999
Creator: Kasili, P. M.; Mobley, J.; Norton, S. J. & Vo-Dinh, T.
Partner: UNT Libraries Government Documents Department

Radiotoxicity of neptunium(V) and neptunium(V)-nitrilotriacetic acid (NTA) complexes towards Chelatobacter heintzii

Description: The objective of this work was to investigate the toxicity mechanisms of neptunium and the neptunium-NTA complex towards Chelatobacter heintzii. The results show that metal toxicity of aquo NpO{sub 2}{sup +} may significantly limit growth of Cl heintzii at free metal ion concentrations greater than {approx} 10{sup {minus}5} M. However, neptunium concentrations {ge} 10{sup {minus}4} M do not cause measurable radiotoxicity effects in C. heintzii when present in the form of a neptunium-NTA complex or colloidal/precipitated neptunium-phosphate. The neptunium-NTA complex, which is stable under aerobic conditions, is destabilized by microbial degradation of NTA. When phosphate was present, degradation of NTA led to the precipitation of a neptunium-phosphate phase.
Date: March 10, 1997
Creator: Banaszak, J.E.; Reed, D.T. & Rittmann, B.E.
Partner: UNT Libraries Government Documents Department

Quarterly report of Biological and Medical Research Division, April 1955

Description: This report is a compilation of 48 investigator prepared summaries of recent progress in individual research programs of the Biology and Medical Division of the Argonne National Laboratory for the quarterly period ending April,1955. Individual reports are about 3-6 pages in length and often contain research data.
Date: April 1, 1955
Creator: Brues, A.M.
Partner: UNT Libraries Government Documents Department

The ELF controversy

Description: This document contains the principal points in a presentation about the Electromagnetic field controversy, including introduction to EMFs, possible health problems, explainations, and exposure doses.
Date: March 1, 1995
Creator: Myers, G.
Partner: UNT Libraries Government Documents Department

Issues in environmental control data used in DD&ER worker dose exposures

Description: Sites for decontamination and decommissioning (DD) or environmental remediation (ER) are often from US DOE operations that began during and shortly after World War II. This paper discusses selected problems in the use of environmental data for DD and ER worker dose exposure calculations.
Date: June 1, 1995
Creator: White, M.G.
Partner: UNT Libraries Government Documents Department

Cleanup of a Department of Energy Nonreactor Nuclear Facility: Experience at the Los Alamos National Laboratory High Pressure Tritium Laboratory

Description: On October 25, 1990, Los Alamos National Laboratory (LANL) ceased programmatic operations at the High Pressure Tritium Laboratory (HPTL). Since that time, LANL has been preparing the facility for transfer into the Department of Energy`s (DOE`s) Decontamination and Decommissioning Program. LANL staff now has considerable operational experience with the cleanup of a 40-year-old facility used exclusively to conduct experiments in the use of tritium, the radioactive isotope of hydrogen. Tritium and its compounds have permeated the HPTL structure and equipment, have affected operations and procedures, and now dominate efforts at cleanup and disposal. At the time of shutdown, the HPTL still had a tritium inventory of over 100 grams in a variety of forms and containers.
Date: February 1, 1995
Creator: Horak, H.L.
Partner: UNT Libraries Government Documents Department

Effective use of metrics in an ALARA program

Description: ALARA radiological protection programs require metrics to meet their objectives. Sources of metrics include; external dosimetry; internal dosimetry; radiological occurrences from the occurrence reporting and processing system (ORPS); and radiological incident reports (RIR). The sources themselves contain an abundance of specific ``indicators``. To choose the site-specific indicators that will be tracked and trended requires careful review. This required the end users to expend valuable time and effort to locate the data they needed. To address this problem, a central metrics database has been developed so that customers can have all their questions addressed quickly and correctly. The database was developed in the beginning to answer some of the customer`s most frequently asked questions. It is now also a tool to communicate the status of the radiation protection program to facility managers. Finally it also addresses requirements contained in the Rad Con manual and the 10CFR835 implementation guides. The database uses currently available, ``user friendly``, software and contains information from RIR`s, ORPS, and external dosimetry records specific to ALARA performance indicators. The database is expandable to allow new metrics input. Specific reports have been developed to assist customers in their tracking and trending of ALARA metrics.
Date: July 1, 1996
Creator: Bates, B.B. Jr.
Partner: UNT Libraries Government Documents Department

Technical basis for dose reconstruction

Description: The purpose of this paper is to consider two general topics: technical considerations of why dose-reconstruction studies should or should not be performed and methods of dose reconstruction. The first topic is of general and growing interest as the number of dose-reconstruction studies increases, and one asks the question whether it is necessary to perform a dose reconstruction for virtually every site at which, for example, the Department of Energy (DOE) has operated a nuclear-related facility. And there is the broader question of how one might logically draw the line at performing or not performing dose-reconstruction (radiological and chemical) studies for virtually every industrial complex in the entire country. The second question is also of general interest. There is no single correct way to perform a dose-reconstruction study, and it is important not to follow blindly a single method to the point that cheaper, faster, more accurate, and more transparent methods might not be developed and applied.
Date: January 31, 1996
Creator: Anspaugh, L.R.
Partner: UNT Libraries Government Documents Department

Preparation-induced errors in EPR dosimetry of enamel: pre- and post-crushing sensitivity

Description: Errors in dose estimation as a function of grain size for tooth enamel has been previously shown for beta irradiation after crushing. We tested the effect of gamma radiation applied to specimens before and after crushing. We extend the previous work in that we found that post-crushing irradiation altered the slope of the dose-response curve of the hydroxyapatite signal and produced a grain-size dependent offset. No changes in the slope of the dose-response curve were seen in enamel caps irradiated before crushing.
Date: January 1, 1996
Creator: Haskell, E.H.; Hayes, R.B. & Kenner, G.H.
Partner: UNT Libraries Government Documents Department

Molecular Characterization of Microbial Communities in a JP-5 Fuel Contaminated Soil

Description: In this study, lipid biomarker characterization of the bacterial and eukaryotic communities was combined with PCR-DGGE analysis of the eubacterial community to evaluate correlation between JP-4 fuel concentration and community structure shifts. Vadose, capillary fringe and saturated-soils were taken from cores within, up- and down-gradient of the contaminant plume. Significant differences in biomass and proportion of Gram negative bacteria were found inside and outside the plume. Sequence analysis of DGGE bands from within the spill site suggested dominance by a limited number of phylogenetically diverse bacteria. Used in tandem with pollutant quantification, these molecular techniques should facilitate significant improvements over current assessment procedures for determination of remediation end points.
Date: April 19, 1999
Creator: Barcelona, M.J.; Chang, Y.-J.; Gan, Y.D.; Macnaughton, S.J.; Peacock, A.; Stephen, J.R. et al.
Partner: UNT Libraries Government Documents Department

Stimulation of the corneal blinking reflex by ionizing radiation

Description: Accelerated alpha particles from the Berkeley heavy-ion linear accelerator were used in a series of experiments designed to elucidate the conditions by which radiation can stimulate or modify nerve action in mammals. Single millisecond pulses in excess of 40,000 radsor pulse trains of less than 1 sec duration elicited the corneal blinking reflex when delivered to the cornea of unanesthetized rabbits. The lowest threshold dose was observed when the Bragg ionization peak was placed at 140 {mu} depth.
Date: May 4, 1961
Creator: Tobias, C.; Luce, J.; Yanni, N.; Brustad, T.; Lyman, J. & Kimura, S.
Partner: UNT Libraries Government Documents Department

US Department of Energy standardized radiation safety training

Description: The following working groups were formed under the direction of a radiological training coordinator: managers, supervisors, DOE auditors, ALARA engineers/schedulers/planners, radiological control personnel, radiation-generating device operators, emergency responders, visitors, Pu facilities, U facilities, tritium facilities, accelerator facilities, biomedical researchers. General courses for these groups are available, now or soon, in the form of handbooks.
Date: February 1, 1997
Creator: Trinoskey, P.A.
Partner: UNT Libraries Government Documents Department

Treatment of patient-dependent beam modifiers in photon treatments by the Monte Carlo dose calculation code PEREGRINE

Description: The goal of the PEREGRINE Monte Carlo Dose Calculation Project is to deliver a Monte Carlo package that is both accurate and sufficiently fast for routine clinical use. One of the operational requirements for photon-treatment plans is a fast, accurate method of describing the photon phase-space distribution at the surface of the patient. The open-field case is computationally the most tractable; we know, a priori, for a given machine and energy, the locations and compositions of the relevant accelerator components (i.e., target, primary collimator, flattening filter, and monitor chamber). Therefore, we can precalculate and store the expected photon distributions. For any open-field treatment plan, we then evaluate these existing photon phase-space distributions at the patient`s surface, and pass the obtained photons to the dose calculation routines within PEREGRINE. We neglect any effect of the intervening air column, including attenuation of the photons and production of contaminant electrons. In principle, for treatment plans requiring jaws, blocks, and wedges, we could precalculate and store photon phase-space distributions for various combinations of field sizes and wedges. This has the disadvantage that we would have to anticipate those combinations and that subsequently PEREGRINE would not be able to treat other plans. Therefore, PEREGRINE tracks photons through the patient-dependent beam modifiers. The geometric and physics methods used to do this are described here. 4 refs., 8 figs.
Date: March 1, 1997
Creator: Schach von Wittenau, A.E.; Cox, L.J.; Bergstrom, P.M. Jr.; Hornstein, S.M.; Mohan, R.; Libby, B. et al.
Partner: UNT Libraries Government Documents Department

Source terms for plutonium aerosolization from nuclear weapon accidents

Description: The source term literature was reviewed to estimate aerosolized and respirable release fractions for accidents involving plutonium in high-explosive (HE) detonation and in fuel fires. For HE detonation, all estimates are based on the total amount of Pu. For fuel fires, all estimates are based on the amount of Pu oxidized. I based my estimates for HE detonation primarily upon the results from the Roller Coaster experiment. For hydrocarbon fuel fire oxidation of plutonium, I based lower bound values on laboratory experiments which represent accident scenarios with very little turbulence and updraft of a fire. Expected values for aerosolization were obtained from the Vixen A field tests, which represent a realistic case for modest turbulence and updraft, and for respirable fractions from some laboratory experiments involving large samples of Pu. Upper bound estimates for credible accidents are based on experiments involving combustion of molten plutonium droplets. In May of 1991 the DOE Pilot Safety Study Program established a group of experts to estimate the fractions of plutonium which would be aerosolized and respirable for certain nuclear weapon accident scenarios.
Date: July 1, 1995
Creator: Stephens, D.R.
Partner: UNT Libraries Government Documents Department

A mathematical approach to optimal selection of dose values in the additive dose method of ERP dosimetry

Description: Additive dose methods commonly used in electron paramagnetic resonance (EPR) dosimetry are time consuming and labor intensive. We have developed a mathematical approach for determining optimal spacing of applied doses and the number of spectra which should be taken at each dose level. Expected uncertainitites in the data points are assumed to be normally distributed with a fixed standard deviation and linearity of dose response is also assumed. The optimum spacing and number of points necessary for the minimal error can be estimated, as can the likely error in the resulting estimate. When low doses are being estimated for tooth enamel samples the optimal spacing is shown to be a concentration of points near the zero dose value with fewer spectra taken at a single high dose value within the range of known linearity. Optimization of the analytical process results in increased accuracy and sample throughput.
Date: January 1, 1996
Creator: Hayes, R.B.; Haskell, E.H. & Kenner, G.H.
Partner: UNT Libraries Government Documents Department

Alpha characterization of concrete surfaces at Decontamination & Decommissioning (D&D) sites

Description: Waste minimization and worker protection at D&D sites requires continual and extensive characterization for radioactive contamination. Contamination detectors that are sensitive, rugged, fast, and capable of covering large areas are needed. The concrete surface monitor (CSM) developed at LANL supports both characterization and waste minimization efforts at D&D sites containing large concrete surfaces and structures of different forms and shapes. This report describes the CSM design and the results of several field experiments.
Date: February 1, 1995
Creator: Vu, T.Q.; Rawool-Sullivan, M.W.; Koster, J.; Stout, D. & Beasinger, A.
Partner: UNT Libraries Government Documents Department

Bayesian methods for interpreting plutonium urinalysis data

Description: The authors discuss an internal dosimetry problem, where measurements of plutonium in urine are used to calculate radiation doses. The authors have developed an algorithm using the MAXENT method. The method gives reasonable results, however the role of the entropy prior distribution is to effectively fit the urine data using intakes occurring close in time to each measured urine result, which is unrealistic. A better approximation for the actual prior is the log-normal distribution; however, with the log-normal distribution another calculational approach must be used. Instead of calculating the most probable values, they turn to calculating expectation values directly from the posterior probability, which is feasible for a small number of intakes.
Date: September 1, 1995
Creator: Miller, G. & Inkret, W.C.
Partner: UNT Libraries Government Documents Department

Dosimetric methodology of the ICRP

Description: Establishment of guidance for the protection of workers and members of the public from radiation exposures necessitates estimation of the radiation dose to tissues of the body at risk. The dosimetric methodology formulated by the International Commission on Radiological Protection (ICRP) is intended to be responsive to this need. While developed for radiation protection, elements of the methodology are often applied in addressing other radiation issues; e.g., risk assessment. This chapter provides an overview of the methodology, discusses its recent extension to age-dependent considerations, and illustrates specific aspects of the methodology through a number of numerical examples.
Date: December 31, 1994
Creator: Eckerman, K.F.
Partner: UNT Libraries Government Documents Department

Verification of AXAIRQ

Description: AXAIR89Q, designed to determine downwind doses following acute atmospheric releases at SRS, has been improved; the new version is AXAIRQ. Improvements include deposition option, new diffusion coefficients, ability to calculate 95% dose at user selected distances, and user-input mixing height. Other improvements also have been made to the format of the output. The user has the option to select the new features or operate the code as AXAIR89Q.
Date: October 1, 1995
Creator: Simpkins, A. A.
Partner: UNT Libraries Government Documents Department