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CHROMOSOMAL ABERRATIONS IN A NATURAL POPULATION OF CHIRONOMUS TENTANS EXPOSED TO CHRONIC LOW-LEVEL ENVIRONMENTAL RADIATION

Description: The salivary gland chromosomes of Chironomus tentans larvae collected from White Oak Creek, an area contaminated by radioactive waste from the Oak Ridge National Laboratory, and from six uncontaminated areas were examined for chromosomal aberrations. White Oak Creek populations were exposed to absorbed doses as high as 230 rads per year or about 1000 times background. Chromosomal maps were constructed to make a general comparison of the banding pattern of the salivary chromosomes of the C. tentans in the East Tennessee area with those of Canada and Europe. These maps were used as a reference in scoring aberrations. Fifteen different chromosomal aberrations were found in 365 larvae taken from the irradiated population as compared with five different aberrations observed in 356 larvae from six control populations, but the mean number of aberrations per larva did not differ in any of the populations. The quantitative amount of heterozygosity was essentially the same in the irradiated and the control population, but there were three times the variety of chromosomal aberrations found in the irradiated area. From this evidence it was concluded that chronic low-level irradiation from radioactive waste was increasing the variability of chromosomal aberrations without significantly increasing the frequency. It was also concluded that chromosomal polymorphism can be maintained in a natural population without superiority of the heterozygous individuals. (C.H.)
Date: January 29, 1964
Creator: Blaylock, B G; Auerbach, S I & Nelson, D J
Partner: UNT Libraries Government Documents Department

Travel for the 2004 American Statistical Association Biannual Radiation Meeting: "Radiation in Realistic Environments: Interactions Between Radiation and Other Factors

Description: The 16th ASA Conference on Radiation and Health, held June 27-30, 2004 in Beaver Creek, CO, offered a unique forum for discussing research related to the effects of radiation exposures on human health in a multidisciplinary setting. The Conference furnishes investigators in health related disciplines the opportunity to learn about new quantitative approaches to their problems and furnishes statisticians the opportunity to learn about new applications for their discipline. The Conference was attended by about 60 scientists including statisticians, epidemiologists, biologists and physicists interested in radiation research. For the first time, ten recipients of Young Investigator Awards participated in the conference. The Conference began with a debate on the question: “Do radiation doses below 1 cGy increase cancer risks?” The keynote speaker was Dr. Martin Lavin, who gave a banquet presentation on the timely topic “How important is ATM?” The focus of the 2004 Conference on Radiation and Health was Radiation in Realistic Environments: Interactions Between Radiation and Other Risk Modifiers. The sessions of the conference included: Radiation, Smoking, and Lung Cancer Interactions of Radiation with Genetic Factors: ATM Radiation, Genetics, and Epigenetics Radiotherapeutic Interactions The Conference on Radiation and Health is held bi-annually, and participants are looking forward to the 17th conference to be held in 2006.
Date: July 21, 2009
Creator: Brenner, David J.
Partner: UNT Libraries Government Documents Department

IBM 650 COMPUTER--PROGRAM NUMBER 655 COLLATION OF ROC CODE OUTPUT

Description: Using the output of programs 653 and 654, each card of which contains the dose information for one dose point at one energy, program 655 produces the sum of the dose values of all energies for one dose point. Program details are given including 650 input and output formats, operating instructions, and guides. (auth)
Date: December 19, 1958
Creator: Stueck, C.J.
Partner: UNT Libraries Government Documents Department

PERIODIC RADIATION SURVEY. CORE I, SEED 1. Section 3. Test Results T- 612394

Description: Radiation levels inside the concrete enclosures but outside the reactor plant containers after shutdown were determined. Radiation levels in the 1AC, 1BC boiler chamber enclosures and in the reactor chamber enclosure were on the average higher than in previous tests. The highest reading obtained was 7.5 mr/ hr and the lowest reading was 0.03 mr/hr; the mean level was 3.76 mr/hr as compared to 1.37 mr/hr in previous tests. (W.L.H.)
Date: June 17, 1960
Partner: UNT Libraries Government Documents Department

Dependance of TWRS FSAR X/Qs on distance and example doses at Highway 240 with stationary and moving receptors

Description: A discussion of the reasons for the dependance of X/Q on receptor distance and compass sector is presented. In addition, X/Qs are calculated for three receptor scenarios on Highway 240 including a moving receptor. Example radiological doses and toxicological exposures at Highway 240 are calculated for two accidents already analyzed in the TWRS FSAR.
Date: September 23, 1996
Creator: Himes, D.A.
Partner: UNT Libraries Government Documents Department

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

Dose refinement: ARAC's role

Description: The Atmospheric Release Advisory Capability (ARAC), located at the Lawrence Livermore National Laboratory, since the late 1970�s has been involved in assessing consequences from nuclear and other hazardous material releases into the atmosphere. ARAC�s primary role has been emergency response. However, after the emergency phase, there is still a significant role for dispersion modeling. This work usually involves refining the source term and, hence, the dose to the populations affected as additional information becomes available in the form of source term estimates�release rates, mix of material, and release geometry�and any measurements from passage of the plume and deposition on the ground. Many of the ARAC responses have been documented elsewhere. 1 Some of the more notable radiological releases that ARAC has participated in the post-emergency phase have been the 1979 Three Mile Island nuclear power plant (NPP) accident outside Harrisburg, PA, the 1986 Chernobyl NPP accident in the Ukraine, and the 1996 Japan Tokai nuclear processing plant explosion. ARAC has also done post-emergency phase analyses for the 1978 Russian satellite COSMOS 954 reentry and subsequent partial burn up of its on board nuclear reactor depositing radioactive materials on the ground in Canada, the 1986 uranium hexafluoride spill in Gore, OK, the 1993 Russian Tomsk-7 nuclear waste tank explosion, and lesser releases of mostly tritium. In addition, ARAC has performed a key role in the contingency planning for possible accidental releases during the launch of spacecraft with radioisotope thermoelectric generators (RTGs) on board (i.e. Galileo, Ulysses, Mars-Pathfinder, and Cassini), and routinely exercises with the Federal Radiological Monitoring and Assessment Center (FRMAC) in preparation for offsite consequences of radiological releases from NPPs and nuclear weapon accidents or incidents. Several accident post-emergency phase assessments are discussed in this paper in order to illustrate ARAC�s roll in dose refinement. A brief description of the ...
Date: June 1, 1998
Creator: Baskett, R L; Ellis, J S & Sullivan, T J
Partner: UNT Libraries Government Documents Department

INDOS: conversational computer codes to implement ICRP-10-10A models for estimation of internal radiation dose to man

Description: INDOS1, INDOS2, and INDOS3 (the INDOS codes) are conversational FORTRAN IV programs, implemented for use in time-sharing mode on the ORNL PDP-10 System. These codes use ICRP10-10A models to estimate the radiation dose to an organ of the body of Reference Man resulting from the ingestion or inhalation of any one of various radionuclides. Two patterns of intake are simulated: intakes at discrete times and continuous intake at a constant rate. The IND0S codes provide tabular output of dose rate and dose vs time, graphical output of dose vs time, and punched-card output of organ burden and dose vs time. The models of internal dose calculation are discussed and instructions for the use of the INDOS codes are provided. The INDOS codes are available from the Radiation Shielding Information Center, Oak Ridge National Laboratory, P. O. Box X, Oak Ridge, Tennessee 37830. (auth)
Date: March 1, 1974
Creator: Killough, G.G. & Rohwer, P.S.
Partner: UNT Libraries Government Documents Department

EFFECTS OF IONIZING RADIATION ON ECOSYSTEMS

Description: The nature of changes that might be induced in ecosystems by ionizing radiation is discussed. Effects of ionizing radiation were studied in two ecosystems at opposite extremes of the temporal sequence characteristic of the Aeciduous Forest: an old field and a near-climax forest. The same general plan of irradiation was used in both systems. A centrally located gamma source produced exposure rates ranging from several thousand r/day within a few meters to about 2 r/day at 130 meters. Highest exposures, continued chronically throughout the winter and spring of 1961-62, caused devastation of both ecosystems, The old-field plant community was intact at daily exposures below about 300 r/day, but the forest suffered loss of the principal plant species contributing to its structure at exposures in excess of 60 r/day. It is evident that there is great variation in radiosensitivity among the plant species of the two ecosystems. The forest ecosystem, considered as a unit, was much more sensitive than the oldfield, the difference spanning a factor of 5-10 in exposure necessary to produce equivalent change in structure. This difference is most likely attributable to differences in stage of succession of the two systems. An hypothesis derived and evaluated from the age/sensitivity relation was that organisms capable of surviving in harsh environments are more radioresistant than organisms of more equable regimes. Factors contributing to the radiosensitivity of various components of the two ecosystems are discussed. (H.M.G.)
Date: January 1, 1963
Creator: Woodwell, G.M.
Partner: UNT Libraries Government Documents Department

RADIATION RESISTANCE TESTS

Description: The complex response of polymers to radiation necessitates knowledge of the radiation resistance and of the effects of radiation type, energy, and intensity on the resistance. A brief discussion is given of the types of radiation and their interactions with materials, and the techniques for measuring the amount of energy absorbed in a material from the radiation field are surveyed. Present-day knowledge of how various parameters and properties of the specimen affect its response to radiation is discussed. Some of the problems peculiar to exposing a sample to radiation are described. Finally, a survey is presented of the status of standard test methods for irradiated polymers. (D.L.C.)
Date: March 18, 1963
Creator: Metz, D.J.
Partner: UNT Libraries Government Documents Department

COMPARISON OF COMPUTED CENTERLINE DOSE RATES FROM DIFFERENT AREAS OF A SOURCE PLATE

Description: A shield fixture that consists of a slab of iron with a cylindrical hole into which plugs of various materials can be inserted is described. Computations made to determine the effect of source-plate size on centerline dose rates are described, and incremental dose contributions from various annular sections of the source plate are presented. Plugs of iron, aluminum, and lead were used in the computations. (auth)
Date: November 1, 1958
Creator: Casper, A.W. & Carver, J.G.
Partner: UNT Libraries Government Documents Department

SAVANNAH RIVER SITE CAPABILITIES FOR CONDUCTING INGESTION PATHWAY CONSEQUENCE ASSESSMENTS FOR EMERGENCY RESPONSE

Description: Potential airborne releases of radioactivity from facilities operated for the U. S. Department of Energy at the Savannah River Site could pose significant consequences to the public through the ingestion pathway. The Savannah River National Laboratory has developed a suite of technologies needed to conduct assessments of ingestion dose during emergency response, enabling emergency manager at SRS to develop initial protective action recommendation for state agencies early in the response and to make informed decisions on activation of additional Federal assets that would be needed to support long-term monitoring and assessment activities.
Date: December 11, 2007
Creator: Hunter, C
Partner: UNT Libraries Government Documents Department

Cryogenic safety aspect of the low -$\beta$ magnest systems at the Large Hadron Collider (LHC)

Description: The low-{beta} magnet systems are located in the LHC insertion regions around the four interaction points. They are the key elements in the beams focusing/defocusing process and will allow proton collisions at a luminosity of up to 10{sup 34}cm{sup -2}s{sup -1}. Large radiation dose deposited at the proximity of the beam collisions dictate stringent requirements for the design and operation of the systems. The hardware commissioning phase of the LHC was completed in the winter of 2010 and permitted to validate this system safe operation. This paper presents the analysis used to qualify and quantify the safe operation of the low-{beta} magnet systems in the Large Hadron Collider (LHC) for the first years of operation.
Date: July 1, 2010
Creator: Darve, C.
Partner: UNT Libraries Government Documents Department