The results of a study are presented which provided additional experimental-loop irradiation space for the AECDRD testing program. It was a premise that the experiments allocated to this reactor were those which could not be accommodated in the MTR, ETR, or in existing commercial test reactors. To accomplish the design objectives called for a reactor producing perturbed neutron fluxes exceeding 1O/sup 15/ thermal n/cm/sup 2/-sec and 1.5 x 1O/sup 15/ epithermal n/cm/sup 2/-sec. To accommodate the experimental samples, the reactor fuel core is four feet long in the direction of experimental loops. This is twice the length of the MTR core and a third longer than the ETR core. The vertical arrangement of reactor and experiments permits the use of loops penetrating the top cap of the reactor vessel running straight and vertically through the reactor core. The design offers a high degree of accessibility of the exterior portions of the experiments and offers very convenient handling and discharge of experiments. Since the loops are to be integrated into the reactor design and the in-pile portions installed before reactor start-up, it is felt that many of the problems encountered in MTR and ETR experience will cease to exist. Installation of …

Reactivity changes, flux variations, and detector-response variations for ZPR-III fast critical assemblies, due to variations in heterogeneities caused by various intradrawer configurations of fuel and diluent plates and deviations of reactivities from ideal homogeneous cores, are calculated as reflective boundary slab cells using the DSN code. For these cells the calculated multiplication constants, for a given assembly plate configuration, by N = 4,8, and 16 approximations successively increase such that the eigen-values obtainbale at N = 16 are still generally far from the limiting values at large N. This aspect makes for uncertainty, especially if differences in k/sub eff/ values from homogeneous are desired. (auth)

A curve relating the output signal from the thin-walled ionization chambers of the cosmotron to the number of protons passing through the chambers for fast r-f turnoff is presented. (D.C.W.)

The charged particle optics of symmetric and asymmetric spectrometers was developed, taking into account the effects of fringing fields. Formulas are given for: the image of point and extended sources, and their resolution and transmission. The suppression of ghost peaks arising from multiloop trajectories was studied. Methods and tables for the calculation of instruments are given. A comparison was made between various instruments already constructed, and some general considerations concerning the choice of design parameters are presented. The correction (for fringing field effects) of sector profiles of instruments already constructed was analyzed, and formulas are given which permit the calculation of modifications of the profiles necessary to insure good focusing with high transmission. Tables include: general trajectory functions; profile curves; and dispersion and transmission functions for symmetrical instruments. (auth)

Results of studies with ZPR-IH Assembly 29, a mockup of a typical, dilute UO/sub 2-/-fueled fast reactor, are reported. The assembly consisted of a 454-liter cylindrical core, blanketed with depleted uranium, with a critical mass of 42l kg U/sup 235/. Experimnents included measurements of fission rates, material reactivity worths, and Rossi alpha. The results of multigroup calculations using the present Argonne cross-section sets are presented, and discrepancies between experimental results and calculations are discussed. (auth)

Rates of decomposition are reported for the tributyl phosphate complexes of uranyl nitrate and nitric acid under isothermal and adiabatic conditions. These data are used to estimate conditions at which the decomposition reaction becomes self-accelerating. (auth)

The results of various experiments and tests conducted on the Experimental Boiling Water Reactor are presented. The reported results represent only a part of the over-all experimental work and were selected on the basis of general value to those interested in nuclear science and engineering. Results are given from tests on system components, power output, radiation and flux, control system, physics, dynamics, fuel, and water-chemistry and corrosion. (W.D.M.)

An evaluation was made of the effect of the liquid-phase viscosity on slip ratio using a forced-circulation two-phase two-component system operating at atmospheric pressure for air and glycerol-water mixtures. The effect of liquidphase viscosity on pressure drop was observed, and the flow regimes were identified and studied. The approximate ranges of the variables investigated were: liquid viscosity, 0.75 to 500 cp; quality, 0.005 to 0.0184; liquid flow rate, 0.2 to 0.8 Ib/sec; air flow rate. 0.001 to 0.015 Ib/sec; and void-volume fraction, 0.34 to 0.78. The vold-volume fraction and the approximate distributlon of the two-phase mlxture at a particular cross-sectional element of the test section were determlned by -attenuation techniques. The slip-ratio and pressure-drop results were not found to Indicate any considerable variations caused by changes in flow pattern or liquid flow rates for the range of flow conditions and liquid viscosities encountered. (B.O.G.)

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Separate equilibrium data were obtained for the distribution of Dy(NO/ sub 3/)/sub 3/- HNO/sub 3/, Er(NO/sub 3/)/sub 3/- HNO/sub 3/, and Dy(NO/sub 3/)< i3>iEr(NO/sub 3/)/sub 3/-HNO/sub 3/ systems between water and tributyl phosphate. Equilibrium data for the Dy(NO/sub 3/)/sub 3/- HNO/sub 3/ and Er(NO/sub 3/)/sub 3/ -HNO/sub 3/ systems were correlated in such a manner that the total distribution of solutes and nitric acid could be found for the Dy(NO/sub 3/)/sub 3/- Er(NO/sub 3/)/sub 3/- HNO/sub 3/ system. The separation factor between Dy(NO/sub 3/)/sub 3/ and Er(NO/sub 3/)/sub 3/ is shown as a function of the total molality of the aqueous phase. A method is presented for predicting the concentrations of Dy(NO/ sub 3/)/sub 3/, Er(NO/sub 3/)/sub 3/, and HNO/sub 3/ in an organic phase of tributyl phosphate from their concentrations in the aqueous phase at equilibrium, and the results of the method are compared with experimental data. (D.L.C.)

A study of the extraction characteristics of the three systems lanthanum nitrate--nitric acid--water--tributyl phosphate, praseodymium nitrate--nitric acid--water--tributyl phosphate, and lanthanum nitrate--praseodymium nitrate nitric acid -water--tributyl phosphate was conducted. The separation factors between praseodymium and lanthanum for the system lanthanum nitrate--praseodymium nitrate-nitric acid--water--tributyl phosphate were shown to be a function of the total nitrate concentration of an equilibrium phase and practically independent of solute composition. A method of predicting the concentrations of lanthanum nitrate, praseodymium nitrate, and nitric acid in an equilibrium phase of the system lanthanum nitrate--praseodymium nitrate--nitric acid--water--tributyl phosphate was presented. A comparison of the extraction characteristics of the system rare-earth nitrate--nitric acid--water--tributyl phosphate for the nitrates of lanthanum, praseodymium, neodymium, and samarium was made. (auth)

Separate abstracts were prepared for 10 papers presented at this meeting. (C.H.)

The distribution of the kinetic energy of fragments emitted as a result of the neutron-induced fission of Th/sup 232/ has been determined. Incident neutron energies of 1475 plus or minus 35 kev and l600 plus or minus 35 kev were used. The distributions determined at the two incident neutron energies are identical. The measured total average fragment kinetic energy was l55 plus or minus 4.5 Mev. The most probable fragment mass ratio is 1.47 plus or minus 0.05, and the average kinetic energies of the light and heavy fragments are 95 plus or minus 2 and 60 plus or minus 3 Mev, respectively. The experimental results were related to the known systematics of neutron-induced and spontaneous fission. The effect of collective nuclear rotations at the saddle point is discussed, with particular emphasis on fission from specific rotational bands. (auth)

A study was made of approximately 132 reports on gascooled reactors and related subjects. Charts and tables containing the following information are included: all available reactor information, reactor flow diagrams of suggested concepts, possible core arrangement at core cross section, typical fuel and moderator cell. possible fuel types for unit fuel cell, the properties of materials for moderators and reflectors. the compatibility of gases and base fuel materials at maximum surface temperatures, maximun interfacs temperatures of fuel elements and core-jacket combinations, allowable operating temperatures and compatibility of gases and various metals. prefenences for gas coolants, cost and availability of gases plant thermal cycle efficiencies, thermal properties of gases, pumping power and reactor coolant inlet temperatures, obtainable heat fluxes, composition and physical properties of potential cladding materials. atomic and themal properties of cladding materials. fabrication characteristics and costs of cladding materials. possible process applications of gases at high temperature, and potential high-temperature materials. The various categories of gas-cooled reactors and examples of each type are discussed. A gas reactor program for high-temperature experimentation is proposed. (M.C.G.)

This document details activities of the Hanford Operations Office during the month of November 1960. (FI)

An investigation was made of methods for decontaminating the primary loop of the New Production Reactor (NPR). Decontamination factors ranging from fifty to several thousand were obtained with several different combinations of cleaning solutions. In general, fission product activity was removed to a lower residual level than was activated corrosion product activity, and carbon steel was easier to decontaminate than was stainless steel. It was necessary to completely remove the oxide film from the metal surfaces to obtain adequate activated corrosion product decontamination. Descaling procedures were also satisfactory for decontaminating fission product and uranium dioxide contamination. (M.C.G.)

Over-all mass transfer coefficients were determined independently of the interfacial area by considering the operation of the pulse column to be a stage- wise process. The calculated coefficients describe only the operation of the pulse column for the free rise of organic droplets through a stage, since in the downstroke the aqueous phase passes through the organic phase in the form of rivulets preferentially wetting the plates. The driving force for transfer was based on the aqueous phase concentrations. The mass transfer coefficient was found to increase when the interfacial tension was reduced. Two factors appear to affect the mass transfer coefficient as the pulse frequency is changed and are: a) recycle or backmixing which tends to decrease the coefficient through a reduction of acetic acid in both phases and thereby increases the interfacial tension, and b) turbulence which enhances the coefficient by reducing the continuous film resistance. The first is important at or near the lower flooding limit, but the latter is the controlling factor at higher frequencies. (D.L.C.)

The final design of the operating control rods for the Enrico Fermi Atomic Power Plant was completed. Two such rods are located near the center of the reactor, which is sodium cooled. Boron carbide is used as poison material. A flow distribution test and analysis, thermal analysis, and stress analysis of the rod were performed for both the normal operating and scram conditions. The test and analysis show that the design meets APDA specifications. (auth)

Preliminary results and data are given for eight expenimental and theoretical nuclear physics projects under investigation. Those projects not reported are listed separately with a reference to the last issue in which each appeared. Separate abstracts were prepared for the eight activities. (For preceding period see ANL-6214.) (W.D.M.)

Uranium dioxide clad with Type 304 stainless steel was fabricated into rod, tubular, and flat-plate shapes by the gas pressure-bending process. Modifications of these basic designs included compartmented rods, corrugrted rods, and compartmented plates. The cold-compacting behavior in methods other than direct cold pressing and the pressurebonding behavior of seven commercial oxides and various mixtures were defined. Through the selection of initial oxides and compacting procedures, final oxide densities of 86 to 99.5% of theoretical were achieved. It was noted that the oxides tend to approach stoichiometry during the pressure-bonding process. Permeability measurements of high-density pressure-bonded uranium dioxide resulted in values that were within the blank rate of measuring apparatus, indicating equivalence to high-density sintering oxides. Thermal-conductivity measurements on similar materials also are consistent with high-density oxide as prepared by pressing and sintering. Of the oxides investigated, mixtures of ceramic and fused oxides appear to offer the most promise of achieving low-cost fuel elements through the pressure-bonding process. Such mixtures containing from 30 to 60 wt.% ceramic oxide provide a high initial pressed density and also permit achieving a high final density. Both oxides are low-cost materials. The preparation and pressure bending of uranium dioxidestainless steel cermets were also briefly …

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In irradiations of rod cluster and tubular fuel elements and fuels rods in NaK-filled capsules, the Zircaloy-2 cladding has failed by necking in localized region. Purpose of the proposed tests to to help establish cladding thickness tolerances for NPR fuel elements, and to study the failure mechanism and influence of several variables.

For a measurement of the diffusion constant D from the decay of the fundamental mode only, optimal dimensions of the pile are given, leading to a fast decay of the higher modes. Another method is discussed which makes use also of higher modes. Evaluation formulas and optimal pile dimensions for this method are derived. The amplitudes of the normal modes are calculated for different initial distributions of the neutrons by means of the Fermi age theory. The error introduced using Fermi age theory was fixed moderator atoms for the slowing down process down to thermal energy is estimated. In one instance, for a simple initial distribution of thermal neutrons, the neutron density was calculated as a function of space and time. The data obtained were used to check the accuracy of some approximate evaluation formulas derived here. (auth)

A project to provide information on the hazards associated wlth arc melting of Th is described. A general airsampling analysis was made to determine the separation, concentration, and distribution of Th daughter (decay) products throughout arc melting, machining, and forging processes found in a handling facility. The value of well coordinated health physics program is stressed in connection with potential health hazards and personnel protection. Building, equipment, and exhaust ventilation requirements for such a facility are discussed, along wlth special handling methods. (auth)