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A 200-Watt Conduction-Cooled Reactor Power Supply for Space Application

Description: The limited supply of relatively long-half-life isotopes having a reasonably high power density and the low conversion efficiencies obtainable with thermoelectric devices have so far limited the power output of isotope-fueled sources of electric power to several tens of watts. In addition, the high cost of the available isotopes results in a very large expense for isotope-fueled generators producing several hundred watts. It appears that a small, minimumweight, conduction-cooled reactor is an attractive alternate to the isotope-fueled power supplies in the 200-w size range. The proposed reactor is a small, high-density fast core of U/sup 233/ surrounded by a beryllium reflector. This approach, generally speaking, gives a reactor that is more compact and of lighter weight than can be obtained with a moderated system having a softer neutron spectrum. In the reactor design, the path of heat flow is from the core to the inner reflector and then to the thermoelements in close contact with the inner reflector. The reject heat flowing from the thermoelement cold junctions enters the outer pontion of the reflector, which acts as the heat sink and conducts the reject heat to the large, circular, tapered-fin radiator which is attached to the reflector. Survey physics calculations for various reactor systems fueled with U/sup 235/, U/sup 233/, and Pu/sup 239/ are reported. Some limits imposed on the system design by the thermoelectric generator are discussed, and the problem of radiator design for the space environment is treated in some detail. No attempt is made to present a detailed final design of the power supply; rather, the report is restricted to a general delineation of the limits imposed by various parameters and a resulting final conclusion as to the performance limits of small conduction-cooled reactors in this size range. (auth)
Date: March 1, 1963
Creator: MacFarlane, D. R.
open access

1559/RE: A CODE TO COMPUTE RESONANCE INTEGRALS IN MIXTURES

Description: The computer program 1559/RE is an experimental IBM-704 code in FORTRAN language for computing the resonance integrals of isotopes in mixtures in the presence of hydrogenic moderation. There may be up to four isotopes, each with no more than 75 resolved resonance levels. Doppler broadening and interference scattering are included No estimate is made of contributions from unresolved resonances. Typical running times are 30 min (with no Doppler broadening) to 90 min (with Doppler broadening) for problems involving 67 levels and unit lethargy widths. Input and theory are discussed, and a typical listing is given. (auth)
Date: May 1, 1963
Creator: Kelber, C.N.
open access

Accurate Nuclear Fuel Burnup Analyses; Eighth Quarterly Progress Report, (September - November 1963)

Description: The objective of the Accurate Nuclear Fuel Burnup Analyses program is to develop more accurate methods for burnup analysis for general use than the current method of analysis of Ca-137 or Sr-90. The program will require from three to five years of effort.
Date: December 1, 1963
Creator: Rider, B. F.; Ruiz, C. P.; Luke, P. S., Jr.; Peterson, J. P., Jr. & Smith, F. R.
open access

Acute Gamma Irradiation of Quercus Seed--Its Effect on Germination and Seedling Growth

Description: Dormant seed of Quercus alba and Quercus rubra were irradiated with gamma rays from Co/sup 60/ to determine the efiect on cytological and morphological expression in the resulting seedlings. Investigations included varying moisture content and physiological state of the seed prior to treatment, and preliminary evaluation of induced mutation. The following observations were made. The lethal radiation exposure was the same for both species although there were differences in germination within the treatment range of 1 to 10kr. Quercus alba showed an LD/sub 50/ of 6kr with a significant regression for radiation level. The regression of germination on radiation level was not significant for seed of Quercus rubra, but germination was suppressed at the higher levels. These species differences are thought to be due more to physiological than genetic factors. Height growth in the two species was complexed by sprouting in reaction to radiation damage of the apical primordia. Seedling height at the end of one year was not a significant measure of radiation damage. The type of sprouting obtained is discussed in relation to diplotonic selection within the irradiated embryonic primordia. Growth of the root at 10 days following inception was established as a macro-measure of genetic damage. Changes in moisture content (above 25%) or metabolic activity prior to germination did not significantly change the response of root growth to radiation exposure. It is suggested that initial root growth is useful as a bioassay of radiation effect on the seed of woody angiosperms where sprouting is comraon. The range of 1 to 10kr is recommended for use in oak seed irradiation experiments for the induction of mutations. Preliminary evidence at the end of the first growing season indicates that most aberrations observed are generally deleterious to total growth. However, many of the irradiated seedlings were as large as the …
Date: January 1, 1963
Creator: Stairs, G. R.
open access

Adaptation of a Commercial Counter X-Ray Diffractometer for Investigations to 3000 C

Description: A General Electric XRD-5 diffractometer equipped with a scintillation counter, a pulse height discriminator, and a modified version of the Model X-86G high-temperature diffractometer attachment, was modified for x-ray diffraction analysis at temperatures up to 3000 deg C. These modifications include frame assemblies, viewing port, filament materials, and thermocouples. (D.L.C.)
Date: February 1, 1963
Creator: LaPlaca, S.; Farber, G. & Adler, G.
open access

Advanced, graphite-matrix, dispersion-type fuel systems. First annual report, April 1, 1962--March 31, 1963

Description: Declassified 4 Sep 1973. A hot-working device for compression of graphite bodies was used to deform cylindrical specimens of matrix graphite containing ZrC or UC-ZrC particles to strains of the order of 30% at temperatures of 2400 to 2900 deg C. The graphite bodies containing ZrC particles (chosen as representative carbide particles) were found to be more plastic near 2500 deg C than similar bodies containing no carbide particles. Microradiographic techniques were used to determine diffusion coefficients of U and Th on actual coated particles by nondestructive means. A tentative energy of activation for the migration of uranium from UC/sub 2/ particles into PyC coatings was determined over the temperature range 1850 to 2300 deg C. The penetration of U into the coatings is not uniform but occurs radially in localized positions, and then spreads circumferentially, creating a banded structure. These results show the importance of the structure of PyC in regard to the diffusion of both fuel and fission-product materials. It was also observed that the diffusion of U is considerably more rapid in the direction parallel to the layer planes in the PyC than it is in the perpendicular direction. Tests with PyC-coated (U, Zr)C particles in graphite-matrix compacts showed that the addition of Zr to the uranium carbide greatly improves the thermal stability. In general, the coatings on these particles retained their integrity for several hours at 2300 and 2500 deg C. (29 figs) (DLC)
Date: May 1, 1963
Creator: Goeddel, W.V.; Sandefur, N.L. & White, J.L.
open access

The AECProgram of Atmospheric Radioactivity and Fallout Research

Description: From Health Physics Society 8th Annual Meeting, New York, June 1963. The Atomic Energy Commission's research program on atmospheric radioactivity and fallout is reviewed. The main purpose of the research program is to provide an increasingly complete and sound scientific basis for the prediction of radiation doses to man that may result from the introduction of radioactive material into the atmosphere. Techniques and computation models for making such predictions are discussed. Emphasis is placed on studies of world-wide transport and distribution phenomena associated with fallout from weapons tests and low- altitude local problems arising from industrial and laboratory operations. The program is conducted through research contracts with universities, industrial organizations, and interagency agreements with other government agencies and AEC facilities. A list is appended of current participants in the program. (C.H.)
Date: January 1, 1963
Creator: Klement, A. W., Jr. & Holland, J. Z.
open access

Aerospace Nuclear Safety Ground Test Program

Description: The assessment (by ground testing) of effects of mechanical actions, thermal and chemical interactions, and nuclear reactions upon tue safety of nuclear power sources that are intended for aerospace applications is discussed. Progress in general studies and in testing of SNAP-9A and -10A is reviewed. (T.F.H.)
Date: September 1, 1963
Creator: Colp, J. L.
open access

Alpha-Gamma Angular Correlation Measurements With Liquid Sources

Description: Alpha-gamma angular correlation measurements were made with solid sources of Am/sup 243/ and with liquid sources containing either Am/sup 243/ or an even-even alpha emitter in dilute perchloric acid solutions. Even-even alpha emitters studied are U/sup 232/, Th/sup 230/, and Ra/sup 226/ . Thicknesses of the soli d sources were controlled so that the neptunium recoils from one source were stopped in Am/sub 2/O/sub 3/, while recoils from the other sources were stopped in the aluminum, gold, or mica backing on which the sources were vaporized. The liquid sources were films consisting of 3 microliters of solution placed between a rubber hydrochloride membrane and a microscope cover glass, 1 cm/sup 2/ in circular cross section. The perchloric acid concentration of the liquid sources ranged from 0.5 to 3.0 molar. All of the angular correlations obtained with solid Am/sup 243/ sources were attenuated, the average attenuation coefficients being 0.29 450 deg C in a 0.01 for sources in which recoils were stopped in Am/sub 2/O/sub 3/, 0.20 450 deg C in a 0.01 for sources in which recoils were stopped in mica, 0.52 450 deg C in a 0.02 for sources in which recoils were stopped in gold, and 0.67 450 deg C in a 0.01 for sources in which recoils were stopped in aluminum. Unattenuated angular correlations were obtained with liquid sources containing Am/sup 243/ in 0.5 M and 1.0 M HClO/sub 4/ . For liquid sources containing Am/sup 243/ in 3.0 M HClO/sub 4/, the correlation was attenuated, with an average attenuation coefficient of 0.86 450 deg C in a 0.01. Attenuated angular correlations were also found with liquid sources containing an even-even nuclide in dilute aqueous solutions The average attenuation coefficients for the even-even nuclide liquid sources were G/sub 2/ = 0.75 450 deg C in a 0.05 …
Date: February 1, 1963
Creator: Murphy, E.S. Jr.
open access

Analysis of the Reactivity Characteristics of Yankee Core I

Description: The reactivity characteristics of the operating Yankee Core I are analyzed. Calculations of kinetic parameters, kinetic coefficients, control rod and boron worth, core lifetime and burnup rate, and fission product poisoning, are described. A large amount of experimental data obtained during Core I operation is included and comparisons are made between prediction and experiments. (auth)
Date: January 1, 1963
Creator: Poncelet, C. G.
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