Brazing alloys such as 48 Ti-48 Zr-4 Be (wt%) and 49 Ti-49 Cu-2 Be (wt%) have been found to readily flow on oxide and graphite ceramics. Two demonstrati on fuel element assemblies were fabricated to illustrate the usefulness of these procedures for nuclear applications. One of these assemblies contained graphite tubes and end caps which were brazed to a molybdenum hanger. The second demonstration fuel element was composed of a compartmented aluminum oxide plate to which aluminum oxide cover plates were brazed. (R.J.S.)

Introduction: The Texas A. and M. Activation Analysis Research Laboratory has been studying the basic technology of activation analysis and its applications since 1958, under the spondorship of the Division of Isotopes Development, U. S. Atomic Energy Commission, and more recently, the National Aeronautics and Space Administration. The information presented in this report summarizes the progress which has been made in these efforts during the period from May 1, 1961, to October 31, 1962.

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A problem which frequently arises in experimentai heat transfer work is that of determining the surface temperature of a tube in which heat is generated electrically. Solution of this problem involves a temperature measurement of the opposite surface to which a correction factor, the temperature drop through the tube wall, must be applied. This temperature drop is obtnined through the solution of the diffurential equation governing the temperature distribution in the tube wall; however, in the case of temperature-dependent properties of thermal conductivity and electrical resistivity, the governing equation is nonlinear, which necessitates special solutions. In this study a hypothetical surface-temperature problem was established, and the solution of the governing nonlinear differential equation was accomplished by means of an electronic analog computer. Assuming variable properties, the example used in this study was that of a one-dimensional steadystate heat flow through both a thick- and a thin- walled tube. (auth)

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With the advent of increasing reactor lifetimes, the need for an accurate description of all fission product cross sections developed in an operating reactor is apparent. An exact analytical method is outlined by which the detailed time-dependent concentration of each fission product and other generated nuclides can be calculated. Radioactive decay and neutron absorption in the time-dependent reactor flux are explicitly included. In addition to U/sup 235/ several fissile nuclides may simultaneously provide a source to the fragment concentrations. The method is demonstrated by calculating both the individual and total thermal and resonance cross sections per fission of 183 fission products from U/sup 235/, natural uranium, enriched uranium, and Pu/sup 239/ in a variety of irradiation flux histories and spectra. All known fission products of significance, i.e., those formed by direct fission yields and their progeny formed by neutron absorption and radioactive decay, are included in the analysis. This is in contrast to treatments heretofore that have largely ignored coupling systematics. A comparison of the aggregate absorption cross sections, determined by both calculation and experiment for a highly enriched sample, which has been irradiated in the MTR to 81% U/sup 235/ depletion, shows agreement within 2% thermally and 15% epithermally. …

A compilation was prepared to aid design engineers in the selection of potential fuels for advanced hightemperature reactors. Available data are included on critical properties for all fuels believed to be potentially capable of operating at surface temperatures of at least 650 deg C. Fuels of recent interest with this capability are included even though sufficient data for their final evaluation are not yet available. The compilation is broken down into sections devoted to particular types of fuels. Property data for all these materials are arranged in a standardized format designed for rapid consultation. In addition to these data sheets, a master table that permits comparison of all fuels covered in the compilation on the basis of four properties considered essential in an initial fuel evaluation is presented. Also, a compilation of appropriate conversion units has been included for the design engineer's convenience. (J.R.D.)

Aberrations of bending magnets and quadrupoles for paraxial rays are discussed, with particular emphasis on isolating those effects likely to be of practical importance in high-energy separated beams. (auth) netohydrodynamically supported shock wave follows the

The nitridation rates of U--5% fissium alloys were investigated at about 200 to 650 deg C and at N/sub 2/ concentrations in Ar from about 0.5 to 100%. The effects of Na coatings and irradiation of the alloy were examined. The nitridation rates of the ailoys followed a parabolic law, with activation energies between 14 and 16 kcal/mole. The ignition behavior of irradiated alloy in N/sub 2/-Ar mixtures was investigated briefly. (auth)

Three tubes were removed from the PRTR for detailed postirradiation tests and inspections. The room temperature burst properties, depth of fretting corrosion, changes in grain structure, and the extent of crevice corrosion were determined. The observations may be summarized as follows: (1.) Irradiatlon to 10/sup 20/ nvt (E > 1 Mev) produced a small increase in room temperature burst strength and a decrease in ductility. The uniform deformation of the specimen prior to the local bulging that precedes failure decreased to a negligible amount at the highest exposure. One tube failed when a short crack propagated through the wall nt a stress equivalent to about 85% of ultimate burst stress. The crack did not then propagate the length of the specimen under these severe circumstemces which indicates that the material is still behaving in a ductlle manner at room temperature. (2.) Close-up visual examination revealed thrt the fretting corrosion marks appeared much the same as in photos taken through the borescope. Depths of penetration from standard fuel element end brackets were found up to 6 mils deep. Outer wire wraps and, occasionally, individual rod wire wraps caused similar penetrations of the tube wall. Bands on Pu--Al elements did not cause …

Notes and edited data from lectures are presented on the history and development of the EBWR, experimental and support study facilities at ANL, EBWR components and materials design, shielding, control rods and control rod drives, fuel design and behavior, water chemistry and corrosion, heat transfer, reactor physics, reactor instrumentation, and reactor safety. (J.R.D.)

Dual neutron diffractometers were designed and built for use at the CP-5 reactor with a number of special features: (1) Two monochromntors are used in an in-line arrangement, as suggested by Levy and Peterson, utilizing the same primary beam with two independent diffractometers, one a horizontal instrument and the other a vertical unit. (2) The two monochromnting crystals may be used in transmission or reflection, and each crystal may be accurntely positioned by external controls. (3) Considerable variations in the wavelength of the primary beam may be made for both diffractometers by changing the take-off angle from the monochromator crystals by means of interchangeable pie-shaped segments. (4) The monochromating crystals are located inside of a relatively small, heavily shielded housing which consists of lead, steel, Boral, and depleted uranium walls which have slotted holes for the exit of two beams, one for the horizontal and the other for the vertical unit. (5) The monochromator housing is surrounded with a large moderating shield which consists of stacked 2-in.thick Masonite die stock forming a 4-ft cube with a minimum thickness of 2 ft from the inner housing. (6) The detector arm on the horizontal diffractometer pivots about the center of the diffractometer …

This report extends and revises LA-2387. Changes in the Los Alamos non- linear least squares program are outlined. A condensed guide for the data card arrangement is presented. The PAKAG code is written in FORTRAN language for the IBM-7090. The system fits a given function to a given data set. The function to be fitted can be any well-behaved'' mathematical function for which the derivatives exist and for which the data set does not give rise to points of singularity. (M.C.G.)

An extensive transient analysis was made of the NS Savannah power plant using analog computer technique to determine the control and safety system actions required to prevent plant damage following operating and accident transients. This work amplified previous design studies by considering accidents of greater severity, automatic limiting devices to preclude safety action, and more realistic parameters based on operating experience. The following transients were analyzed; startup accident, rod withdrawal accident in the power range, excessive steam demand, accidental closing of both steam stop valves, primary flow coastdown, capsize ship accident, ejection of one control rod, determination of maximum and minimum rates of reactivity change thnt should be available to the control system, and power change-from 100 kw-t to 88 Mw-t to determine the reactivity required to maintain a 20-second period. The minimum rate of reactivity removal necessary to prevert plant damage considered to occur when heat flux exceeds the steady-state level corresponding to departure from nucleate boiling, when the central fuel temperature exceeds 5000 deg F, when primary system pressure exceeds 2200 psia, and when the core is not subcritical following a primary system rupture was considered. The effects of changing set points were also analyzed. The graded protective …

Tentative estimates of the sharp''-rising overpressures as a function of duration which represent a lethal hazard to the 70-kg animal 1, 50, and 99% of the time were presented. The predictions were based on interspecies correlations and extrapolations encompassing blast-tolerance data for six mammalian species. The tentative application of the data to indicate human blast tolerance was discussed and relevant uncertainties in the estimates were emphasized. It was also pointed out that biologic tolerance would be different for air-blast pulses having non-ideal wave forms frequently associated with various geometries of exposure. Selected pathophysiological information pertinent to the biological response following blast exposure was given; namely, survival time and selected postshot observations of dogs and goats. (auth)

Results of work in a continuing program to investigate basic processes in thermionic energy conversion related to thermionic nuclear power plants for naval applications are reported. The areas in which progress is reported include statistical mechanics of Cs adsorption, space charge analysis for low pressure thermionic diodes, emission requirements for removal of space charge barriers, unignited mode of thermionic converters, interpretation of volt-ampere characteristics, vaporization and deposition at Cs-covered surfaces, and Cs purification. (auth)

Modifications to the shape of ideal quadrupole magnets were investigated, using an electrolytic tank method. Magnets with straight and with exponential pole faces were considered with 1: 1, 1: 2, and 1:3 apertures. The additional field introduced by these modifications was expressed in an harmonic series and the coefficients of this series plotted against the parameters characterizing the modifications made. (auth)

Design, testing, and early operation of the Argonne Low Power Reactor (SL- 1) that was subsequently destroyed in a nuclear incident are reviewed. Motives determining the design of the control system are explained; and information from tests, operation, and the incident itself is analyzed for the purpose of improving reactor design and operation. (D.C.W.)

A thermionic converter was constructed to evaluate the effect of radiation shields in the interelectrode space. No significart difference was found in the total power and short-circuit currents with and without the radiation shield, although there was evidence that the cell efficiency was higher at intermediate emitter temperatures (1200 to 1800 deg C). An in-ptle test was made with a cell containing a radiation shield surrounding the emitter and connected electrically to the collector. The cell for spectroscopic studies of cesium plasma was assembled and two runs completed without cesium. Metallographic examinations were made of hot-pressed UC-- ZrC fuel pins. An electrochemical technique was devised for cutting a fuel pin from a solid UC-ZrC cylinder. A carbide fuel pin, maintained at 700 deg C, brazed with V to a Nb collector underwent a 400 hr test in Cs vapor at 400 deg C. Potted electrical coils withstood 25 pulses with no visible damage. (M.C.G.)

A method of treating periodic potential problems, which appears to offer some simplifications, is described. The classical Kronig-Penny problem was treated as an introduction to the applications after which the method was used to obtain the band structure for the periodic potential, the parabolic scallop potential,'' consisting of a linear chain of segments of vertical parabolas opening upwards. The general problem for the one-dimensional periodic potential with reflection symmetry was then treated and illustrated by application of the method to the linear chain of inverted parabolic segments. As a third example the band structure was obtained for the hip-roof'' potential. The three- dimensional problem is also discussed. (auth)

The nature of certain critical lesions seen after exposure to air blast is described. The early lethality characterizing primary and tertiary blast damage is emphasized along with the seriousness of injuries caused by blastenergized debris. Tentative criteria are developed to the end that different levels of environmental variations caused by blast phenomena could be quantitatively related to various levels of biological response. Using the free- field scaling laws and a mathematical model whereby translational velocities can be computed for animate and inanimate objects, the criteria are applied to nuclear explosions ranging in yield from 1 kt to 100 Mt. Thus, it is possible to specify, as a function of yield, the hazard ranges inside which various blast injuries might occur. At these ranges the associated levels of initial nuclear and thermal radiation were computed to allow at least some assessment of the relative importance of all the major hazards from nuclear detonations. (auth)

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