From the standpoint of erosion, a long dump line may be preferable to a throttling dump valve to achieve the pressure drop from the HRE-3 slurry blanket to the dump tank. Extended length HRE-3 dump lines in which the maximum average velocity is 20 fps, the smallest allowable line size is 1/2 in., and the time for dumping is 10 minutes are investigated. Twenty-six parallel 1/2-in. Sch. 80 pipes, each 725 ft long, or four parallel 1 1/2-in. Sch. 80 pipes each 2,000 ft long are required. To avoid localized velocities considerably higher than 20 fps as a result ef flashing, these pipes can be submerged in a 25,000 gal pool of water initially at 135 deg F and with 40 deg F allowable temperature rise. It can be concluded that if the velocity, line size, and dumping time are limited to the values listed above, use of restrictor piping to achieve the pressure drop is not very practical. If higher velocities and flashing are allowed, a cursory study indicates that for an average velocity in the range from 100 to 200 fps, one 1 1/4-in. (or smaller) line of less than 250-ft length could be used. Flashing would occur, …

The hazards associnted with the use of magnesium capsules in a CO/sub 2/- cooled reactor system have been analyzed, and consideration has been given to incidents which could lead to excessive temperature excursions and factors which could significantly reduce the ignition temperature of magnesium alloys. Methods of reducing the hazards associated with the Calder Hall type of reactor are discussed, and an experimental approach with which to define more aaccurately conditions that would lead to ignition is suggested. (auth)

Shielded enclosures equipped with viewing devices and remote-hauling equipment for use in experiments and processes involving radioactivity are referred to as hot cells. The hot cell includes the biological shield enclosing the working space, viewing devices, special ventilating equipment, and special equipment for use in the hot cells, such as manipulators, cranes, machine tools, and measuriag devices. A hot cave is the same as a hot cell. A junior hot cave is a small-sized hot cave. A summary is presented of pertinent data on hot cells in use at various AEC installations. (C.H.)

The pump-to-motor mixing rate of the ByronJackson 4000-gpm pump was determined as a function of motor purge flow. A purge rate of 63 liters/hr, which corresponds to a mixing rate of 0.55 liters/hr, is recommended for operation of this pump. Further increases in purge flow did not decrease the mixing rate significantly below this level. Two runs were made with cooling water bypassing the external motor cooler. These runs indicated that the external cooler was necessary to prevent overheating of the 4000 gpm pump motor. However, the observed heat balance checked the predicted heat balance, indicating that the method of prediction can be applied to the design of motor

An estimate is presented which is intended to establish an expected order of magnitude of resulting thermal neutron-induced activity and relative production of stable and radioactive isotopes in soil. The estimate is based on a one MT weapon (100%) fusion detonated at the surface of Nevada Test Site soil. (W.D.M.)

Program F/sub 3/ provides an anslysts of a three group, one-dimensionni reactor in multi-region slab or cylindrical geometry. Input consists of a description of the geometry of the assembly, energy group constants defining the nuclear characteristics of each region, and control information specifying the type of calculation desired. The fission density and neutron flux, computed at each lattice point, are used to calculate the reactivity of the system. (auth)

The specifications for the D1G reactor pressure vessel and accompanying insulation, shield tank, thermocouples, test heads, fixtures, tools, and repair parts are given- (T-R-H-)

A pile oscillator was designed, constructed, and operated at the Battelle Research Reactor. This pile oscillator cycles a specimen and a standard in the same container through an annular ion chamber located in the thermal column. This almost simultaneous oscillation of the standard and specimen eliminates errors caused by power drifts or fluctuations. The use of a continuous graphite rod for the container or carrier reduces undesirable scattering effects of the carrier. The oscillator was calibrated using the cross section of gold foil as a standard. Effects of geometry on measured cross sections were investigated. In general, larger samples gave higher apparent crosssection values than thin foils of comparable cross sections. Most measurements to date were made on powdered-metal samples. Values obtained at Battelle are presented and compared with values from Oak Ridge on similar samples. At present the sensitivity of the oscillator is limited to total absorption cross sections on the order of 1 mm/sup 2/ for accurate crosssection data. The limit of the accuracy of the measurements is approximately the accuracy to which the absorption cross section of the standard sample is known. An analysis of the errors indicates that cross sections on the order of 1 mm/sup …

Various heat transfer mechanisms which have been previously proposed are analyzed in the light of recent experiments. Evidence is presented in favor of a liquid-vapor exchange mechanism and against the widely accepted "micro-convection" mechanism. The vapor-liquid exchange rnechanism is shown to explain the insensltivity of boiling heat flux to the level of subcooling. A "Reynolds Analogy" for nucleate boiling is presented in some detail. A procedure is given for calculating the superheat at which the liquid bulk velocity ceases to contribute to the heat flux. An expression for the growth of a vapor bubble in a highly superheated liquid is deduced. A method is presented which allows the deduction of correlations for nucleate boiling which give the dependence of heat flux on superheat and system pressure. Two such correlations are presented and results are compared with experiment. It is shown that one correlation yields the heat flux for different liquids varying from water to mercury, without necessitating any change in constant or exponent of the correlation. (auth)

The accuracy with which the breeding ratio of HRE-3 could be determined after a period of reactor operation was investigated. Inaccuracies in measurement of the core U/sup 233/ inventory and blanket U/sup 233/ and Pa/sup 233/ inventories appear to be the major sources of error. Appreciable errors could result from attempting to determine these inventories by sampling the reactor contents. For example, if generalized attack on stainless steel is at a rate of 1.0 mpy and if the associated film of corrosion products is 1% uranium, failure to account for this fuel in evaluation of the core inventory would cause an error of about 5% in the breeding ratio. (auth)

An investigation of trim from the HRP Dump Valve Test Loop revealed that performance improved with increasing poppet hardness. From this it was hypothesized that deformation of softer poppets increased the poppet-seat contact area, thus reducing the closing pressure. The deformation areas of a number of poppets were measured and the closing pressures calculated. A plot of closing pressure against leak rate showed a fair correlation and tends to support the hypothesis. (auth)

A three-stage mass spectrometer that utilizes two consecutive magnetic focusing;lenses of 20-in. radii followed by a 20-in. radius-of-curvature electrostatic analyzer is described. An abundance sensitivity of 1010 was measurcd for this instrument in the low mass region. Application of this instrument to analytical and research problems in the field of mass spectrometry and the results obtained are discussed. (auth)

Work on circuits for high-speed computers, iterative methods for linear equations, hydrodynamic flow problems, and switching circuit theory are reported. The operation and use of ILLIAC for May are summarized. (For preceding period see AECU-3760.) (T.R.H.)

Shielding Computer Program 04-0 is available for computing reactor- shield weight and fast neutron and gamma ray dose rates in and around complex resctorshield assemblies. Reactor and shield geometries are described by combinations of regions formed by rotating rectangles or trapezoids about the reactor axis or by translating rectangles parallel to the reactor axis. Compositions are expressed as volume fractions for each material in the reactor- shield assembly. A cylindrical coordinate system is used to describe the location and dimensions of a volume source. Source distributions are assumed separable and may be described by cosine functions. A modification of the Albert- Welton theory of neutron attenuation is used for fast neutron dose rate calcuiations. Combination of buildup factors is used with exponential attenuation to compute gamma ray dose rates. The program requires four magnetic tape units and two frames of magnetic core memory on an IBM 704. Magnetic drum memory is

The interpretation of the dimensional instability of U- Zr alloy containing small amounts of boron has raised the question of whether the observed low-temperature swelling can be related to the temperatureswelling characteristics of either the U-Zr alloy or Zr- B alloys by themselves. To obtain such information on the Zr--B system to compare with the more detailed study of thc alloy early results of which were reported in KAPL-1562, pieces of previously irradiated Zr- B alloys and dispersions were annealed in vacuum at temperatures between 350 and 750 C. (auth)

Transient effects of making step changes of the core dump tank concentration are studied for single-region operation of the Homogeneous Reactor Test. It is assumed that the feed and the letdown streams are only between the core high-pressure system and the core dump tanks, and that transfer of fuel to or from the blanket can only be made through the core high pressure system. Transfer rates between the HRT highpressure systems of 75 to 100 lb/min will give reasonable mixing times, about 4 hours, without peaking of fuel concentration which may cause premature critical conditions in the core. Lower transfer rates could be used for lower feed rates, but the mixing time will be longer. Transfer rates greater than 100 lb/min would not shorten the mixing time appreciably and, therefore, they need not be considered. (auth)

The electical analog study of the diaphragm feed pump system resulted in changes to the system which have improved the over-all operation and reliability of the pumps. Specifically, the study showed that if the release of the high- pressure oil from the pulsator through the valve on the Scott and Williams pump could be made to take place over a longer period of time, pressure oscillations could be substantially reduced. Also, pressure surges could be reduced by placing an accumulator in the pump discharge line near the check valve. Both of these have been incorporated into sulted in a quieter and smoother operation of the pumping system. (auth)

The reduction in HRE-3 breeding ratio resulting from neutron absorptions in the core-inlet line was examined for spherical and cylindrical cores; it was found to be less than 0.5% if the pipe does not extend more than 1/4 the way from the top to the bottom of the core. The power density at the end of the pipe would be 57 kw/l if it extended 5 in. into the sphere. (auth)

A study has been made of the radiation received by staff members of the 60-inch cyclotron for the period from 1953 to 1957 and of the radiation environment in the target area. The nature of the operations has caused workers to receive an average amount of radiation that was within the formerly acceptcd limits and in addition is less than the present maximum recommended by the AEC. Namely, the Maximum permissible Dose (MPD) to the most critical organs, accumulated at any age, shall not exceed 5 rems multiplied by the number of years beyond age eighteen and the dose in any thirteen consecutive weeks shall not exceed 3 rems. There has been a yearly decrease in average exposure however, and constant improvement of techniques lessens the amount of radiation received. (auth)

BS>Neutron nonelastic cross sections measurcd at different detector biases have been used to determine the cross sections for inelastically scattering 14-Mev neutrons into 9- to 14-Mev energy range. The cross section for producing these high-energy neutrons, which may be attributed to direct interaction processes, is roughly 10% of the nonelastic cross section, for all elements. A comparison is made with data of Coon and co-workers, who measured angular distributions for the samc high-energy inelastically scattered neutron group. (auth)

The insoluble residues produced during the reprocessing of certain nuclear fuel elements containing aluminum, silicon, and uranium were investigated with respect to particle size, shape and distribution, composition, and surface- active tendencies. The fuel material samples studied contained from 0.4 to 7.0% silicon by weight (the high analysis represents a cast base AlSi alloy). The fuel materials were dissolved in mercury-catalyzed nitric acid. Two types of solid residue were produced by actual fuel dissolution. One was a finely divided material, brown in color and the other was black, crystalline material relatively large in size. Only the black crystalline material was obtained when cast AlSi was dissolved in nitric acid. Spectrographic analysis of the residues showed that silicon and alumimum were the major constituents. X-ray diffraction analysis of each type indicated the presence of elemental silicon only. The x- ray pattern obtained with the brown material showed lower intensities indicating the presence of amorphous material. Under a magnification of 970 diametems, the crystals observed appeared to be non-uniform, shallow platelets of irregular shape. The bulk of the residue is remmed by a 10-micron filter: however, the resulting filtration rates are very low. (2.0 gallons per hour per square foot). Sedimentation data …

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An analysis of the temperature structure in the CCR-2 fuel elements and coolant stream at the position where the maximum fuel element surface temperature exists is presented. Results were obtained by numerical methods on the IBM 704 digital computer. The effect of variation in channel size is shown, and a method of data correlation is suggested. Preliminary conclusions are presented as to the effect of temperature structure on the design and testing of gas cooled reactor fuel element configurations. In view of the rate at which gas cooled reactor work is proceeding results of the calculations are being published in their current incomplete form. The study is continuing in an effort to refine the calculations, and experimental data will eventually be available with which to verify the analytical conclusions. (auth)

The stability of the interface between two immiscible fluids moving at a uniform rate through a porous medium is investigated. The conditions for stability are derived, and the rate of growing of instabilities of specified wavelength is obtained. The expression for the rate of growth of instability is similar in form to that obtained by Taylor for the case of uniformly accelerated incompressible liquids, but the growth rate is fouud to be inversely proportional to the wavelength rather than inversely proportional to the square root of the wavelength. (auth)