In connection with the program of the measurement of eta for U233, several critical experiments have been performed by R. Gwin and D. W. Magnuson of ORML with light water solutions of uranyl nitrate (highly enriched in either U233 or U35) in an essentially bare sphere 27 inches in diameter. This report presents the results of two multigroup-diffusion-theory calculations for the above experiments performed by C. B. Mills and associated at Los Alamos. Assumer cross sections, material concentrations detailed neutron balances and a comparison with elementary theory are included. The agreement between the calculated and experimental multiplication constants is excellent for the multigroup calculation but only fair for the elementary calculation. The latter method overestimates the fast leakage so that the computed multiplication constant is less than that found experimentally.

A Lucite model of a multi-stage countercurrent hydroclone solvent extraction apparatus has been constructed and tested with Amsco-water. The diffusivity of Cs 134 tracer in aqueous chloride solution was measured to check the performance of the capillary diffusivity measuring system. The experimental data from four Druhm runs showed that 1/8in. thick graphite liners are usable for reactor temperatures above the boiling point of sodium.

The method of calculation of various quantities relating the temperature and the rate of heat removal of UO2 test elements is presented. Graphs of the appropriate quantities as a function of the rate of heat removal are included.

The nil-ductility-transition (NDT) temperature, as defined by the Naval Research Laboratory drop-weight test, was determined on the A212B carbon-silicon steel used in the pressure vessel of the N. S. Savannah nuclear reactor. Correlations were made with the Charpy-V-notch impact energy at NDT. Specimens taken at two different thickness location from materials used in the upper closure head of the reactor vessel yielded NDT temperatures of 0 - 20°F which correspond to Charpy-V-notch impact energies of 11-19 ft-lb. Testing of as-received material used in the lower closure head indicated that the NDT temperature was 50°F which was equivalent to an average Charpy-V-notch impact energy of 12 ft-lb. After normalizing and stress-relieving this material, in order to more closely approximate the final condition of the reactor vessel, NDT was reduced to less than 10°F.

This memorandum summarizes the results of an analysis to determine the extent of displacement of the EOCR core due to blowdown in case of several postulated hot main gas coolant pipe failures. Results show that the core will be damaged for any hot pipe double-ended failure. Excepting the improbable case of no coolant flow existing proper to the break, the core will be damaged for any hot pipe fracture exposing a total flow area to the atmosphere equal to that of one pipe. Smaller breaks will probably be safe in this respect.

Many elements exhibit anisotropic scattering at energies of interest in reactor calculations. A method is presented for the calculation of transport cross sections including the observed anisotropy.

Preliminary measurements of the corrosion of titanium were made in 13 M HNO3-0.05 M fluoride using 0.1 M H3BO3 as a liquid and vapor phase complexing agent. Titanium Ax-55 was attacked at average rates of 0.58 and 0.33 mils/month in the liquid and vapor. In dissolver solutions containing 0.5 and 1.0 M titanium, all rates were less than 0.1 mils/month.

An improved heat sink for space vehicles was proposed in ORNL-CF-59-1-21. Subsequent work on the problem has indicated that there is a substantial probability of a puncture of such a radiator by meteors. To meet this problem a modified geometry has been evolved for which the probability of a meteor puncture should be reduced by a factor of at least 100 relative to the radiator of the original proposal at the expense of an increase in radiator weight of possibly 30%. This memorandum outlines the approach to the problem and a series of similar promising solutions.

This report describes a computer program--Oak Ridge Thermal Ellipsoid Plot program (OR TEP)--for drawing crystal structure illustrations with a mechanical plotter.

This report presents the results of a study that argues the importance of providing thermal energy from steam-electric power plants to urban areas.

In a discussion about design of cyclotron resonators, the suggestion has been made that a wide range variable-frequency system might be constructed with two coupled resonant circuits. It also would present the possibility of tuning without the switching of high-current contacts, a troublesome item now commonly used for cyclotrons. One of the circuits would be the dee and its stem which might, or might not, be tuned. The second circuit could be located out of the magnet gap in a region where more space is usually available. Tuning could be accomplished by variation of the coupling between the two circuits and/or by, say, variable capacitance of the tuned, or tunable, circuit.

Calculations are given for eighteen stainless steel clad helium bonded specimens of UO2-ThO2 containing normal U to be placed in 6 holes in a holder in a position of the ORR not to exceed a peak unperturbed flux of 4 x 10^14 n.cm^2/sec and irradiated to a peak nvt of 1.96 x 10^21 neutrons/cm^2

The "absolute" containment of ions in the DCX magnetic mirror field resulting from the cylindrical symmetry of the field is discussed. The regions of confinement in space and momentum are plotted for 300 Kev deuterons.

The problem of controlling the surface temperatures of core vessels in two-region aqueous homogeneous reactors has been examined by analyzing several possible systems for cooling the wall: (1) direction of the inlet core fluid along the wall at a high velocity; (2) passage of heavy water through the wall of a double-wall core vessel; and (3) flow of cool blanket slurry past the wall.

The ORIC (Oak Ridge Relativistic Isochronous Cyclotron) radiofrequency system for which Model III represents the resonator is the third system which has received enough consideration to warrant construction of a model. The purpose of the model is to check the calculations for the frequency range and excitation power of the resonator. After an introductory description of the r-f system and model, the detailed calculations of the properties of the model will be given followed by the data from measurements of the model characteristics.

The nuclear characteristics and fuel costs of a number of aqueous homogeneous reactors have been estimated. Most of the reactors studied were cylindrical, two-region power-breeders variously having between 0 and 300 g/l of thorium in the core and between 500 and 1000 g/l of thorium in the blanket. The results of the calculations, including breeding ration, fuel inventories, doubling times, and net fuel costs, are summarized in this report.

Either system appears to be fairly satisfactory from a containment standpoint. Current results indicate probable over-all rates of about 0.2mils/mo for titanium vs. 1.5-3.0 mils/mo for Ni-o-nel. Tests are not 100% comparable due to changes made in flowsheet conditions, but have been of sufficient variation and length as to allow good predictions to be made. Both metals show some tendency toward local attack in Thorex solutions. These tendencies are increased by poor welding techniques.

The purpose of this study was to develop equations for calculating fision product heating in the HRT-CP underflow pot from measured temperatures and to attempt to correlate the rat of solids accumulation in the underflow pot with fission heating and reactor power. Using fission heating data calculated from relating solids accumulation and heating have been tested. In one case an error of no greater than 26% was incurred in the calculation of the total weight of solids collected during chemical plant runs 17-4, 17-5, and 17-6. Further development work will be done on this correlation.

Calculations indicate that single-transfer line concatenated pulse column systems can be operated with static pressures that are not excessive if a sufficient number of vessels are employed in the system. The required number of vessels can be attained by using a series of short columns or by using holdup pots in conjunction with a limited number of columns.

Equilibrium loading of uranium on Dowex 21K has been studied in a sulfate system for uranium concentrations from 0.0005 M to 0.0005 M, total sulfate concentrations of 0.45 M to 0.6M, and sulfuric acid concentration of 0.020 M. Loading data have been fitted to Langmuir adsorption isotherms and Langmuir constants have been evaluated. Resin was equilibrated with uranium feed solutions by flowing the feed through a shallow fixed bed of resin.

The power and estimated reprocessing load are tabulated for existing and proposed United States and United States-built reactors of 10 Kw or greater thermal power.

The addition of a surface active agent to an aqeous-organic interface produced a resistance to mass transfer equivalent to slightly more than 1 cm of water. Five semicontinuous Druhm runs were made with 1/2in. thick MgO liners and terminated due to either failures of the UFe nozzle or a top gasket leak. In preliminary scale-up tests of the flame calcination equipment, a maximum feed rate equivalent to 720 g oxides/hr was achieved using a 3-in. i.d. magnesia reflector with an outside wall temperature of 1500°C.

Data on waste volumes and heat generation of several reactor fuels which may be reprocessed in the Power Reactor Fuel Reprocessing Pilot Plant at ORNL are tabulated.

Several experiments have been performed at ORNL with light water solutions of uranyl nitrate (highly enriched in either U^233 or U^235) in an essentially bare sphere 27 inches in diameter. This report presents the results of several calculations with elementary bare reactor theory and a discussion of the observed discrepancies between the calculated and experimental results. If the observed critical concentration is used in the calculations, the calculated effective multiplication constant is less than unity' thus a higher critical concentration would be predicted than is actually observed.