In the past it was felt that the easiest way to treat a three group equation for a MTA lattice was to solve it without certain terms. This iterative procedure converged rapidly for a medium with depleted uranium fuel, and in fact, a second iteration was not needed.

The energy distributions of neutrons in the 3-10 Mev energy range resulting from the bombardment of thin U targets are being investigated by the measurement of proton recoils in photographic plates.

This report is a corrected copy of the authors "rapporteur talk" at the 1959 Kiev Conference on High Energy Physics. It contains data on the rapporteur system and on interactions of strange particles with protons and neutrons, using data from bubble chambers, counters, and emulsions.

This technical report describes development work done on method of particle separation by the Biology Division of the Oak Ridge National Laboratory and the Oak Ridge Gaseous Diffusion Plant during the period January 1 to June 30, 1963, under the Joint National Institute for Health-Atomic Energy Commission Zonal Centrifuge Development Program. The central effort has been to develop zonal centrifuge systems for the separation of cells and sub-cellular particles, including viruses, and bio-colloids, including proteins and nucleic acids.

Abstract: "The elastic double scattering of deuterons by complex nuclei has been investigated experimentally. Measurements were made on carbon, aluminum, and copper at around 157 Mev; on lithium, beryllium, and carbon at around 125 Mev; and on carbon and aluminum at 94 Mev. The expected tensor components of the deuteron polarization have not been observed. Measurements have been made of the differential cross section and vector-type polarization as a function of angle for the scattering of deuterons from the above elements, at the above energies. The observed polarizations were larger than would be expected on the basis of the individual nucleon-nucleus interactions. In a second experiment we measured the 169-Mev proton-proton polarization at 10, 15, 22.5, 30, and 35 in the laboratory system. The results indicate that partial waves up to and including L = 3 are important at this energy."

The following report provides data that was discovered from a preliminary literature survey that was made to define the utility of the newer refractory ceramics or ceramic-based materials.

A series of two-group calculations has been made on the Oracle for the purpose of obtaining critical-mass and flux distribution data for various ORR core configurations. The 3G3R code of Bate, Einstein, and Kinney was used, together with the RSP code developed by Nelson. This made it possible to obtain results for the three-dimensional case. The results, which are presented graphically, are intended to serve as a guide for the design of experiments until such time as actual measurements are available. The calculations were performed for the "clean cold" case, and it should be realized that the presence in the core of experiments and of fission products built up during operation will materially alter the flux patterns found. It is believed that the critical-mass data are accurate to within 10%. Within the fuel region it is believed that the thermal-flux patterns are the also accurate to this degree. Comparison of the results with MTR critical experiments, however, indicates that the thermal flux in the reflector in the vicinity of the fuel-reflector interface may have been underestimated by a factor of as much as 1.3. It should also be recalled that in a two-group calculation the "fast flux" is often a …

The excitation function for the reaction T3 (p, y) He4 has been extended to proton energies of 7.3 Mev. No experimental evidence is found for a resonance in the reaction up to this energy of bombarding protons.

Abstract: The counting accuracy of the Chicago Scalers, Models 961A and 961B, is a function of the bias setting of the limiter (V2). this report gives quantitative data supporting this thesis. A method of making bias settings is suggested. These tests were run at the suggestion of Mr. V. C. Hanson.

From July 7 to August 31, 1955, 20 tons of uranium and 1,200 g of plutonium were recovered in 47 days of plant operation at an average rate of 833 lb/day of uranium and at a cost of $2.60/lb of uranium. Uranium and plutonium recoveries were, respectively, 99.9 and 95.5 per cent.

The purpose of this note is to recalculate the semi-empirical curve of neutron yield vs. deuteron energy originally obtained by H. York in order to predict, using it and the best available data, what yields may be expected for deuterons on uranium in the extrapolated energy region.

In the operation of nuclear reactors, nuclear fuel reprocessing plants and in-pile experiments, special provision must be made for disposal of gaseous fission products to prevents contamination of the atmosphere to an unacceptable degree. A disposal process is described in which the noble gas fission products, krypton and xenon, are delayed relative to the sweep gas by physical adsorption as they pass through an adsorbent such as activated charcoal. A theoretical plate analysis, and has been verified experimentally. The retention time for a gas present in trace concentration is proportional to the amount of charcoal in the adsorber bed and to the adsorption coefficient which is evaluated experimentally for a particular combination of materials and conditions. The retention time is inversely proportional to the volume flow rate if the sweep gas.

From abstract: "Bis(di-n-hexylphosphinyl)methane, HDPM, [(C6H13)2P(O)]2CH2, has been studied as an extractant for a variety of metals. HDPM was evaluated as an extractant for uranium(VI) and compared with tri-n-octylphosphine oxide, TOPO, (C8H13)3PO. In nonpolar solvents, HDPM forms a polymeric-like substance with compounds of uranium(VI). Viscosity measurements indicate that the molecular weight of this polymeric-like substance is about 100 times greater than the corresponding complex with TOPO. Polymer formation occurs only when nonpolar solvents are used as diluents for HDPM and is easily avoided by using polar solvents such as 1,2-aichlorobenzene. HDPM forms 1:1 and 2:1 complexes with uranium(VI) nitrate. Equilibrium constants for these complexes as well as that for the 2:1 TOPO complex were calculated and it was shown that the over-all constant is at least ten times larger for the HDPM complex than for the TOPO complex. The effect of concentration of various mineral acids, extractant concentration, temperature, and diluents on the extraction of uranium are discussed."

Abstract: "Measurements have been made on pseudo-cylindrical graphite-enriched uranium unreflected systems. These measurements include both critical mass determinations and time dependent measurements using a pulsed neutron source to drive the assemblies."

Abstract: The nonmetallic inclusions in both as-reduced and fabricated dingot uranium have been studied for comparison with those in ingot uranium. Special attention was paid to the hydride for the purpose of determining the amount and distribution in the various types of uranium. The types and distribution of other inclusions were also studied. It was found that the dingot uranium was of a higher quality than ingot uranium and was comparable to as-reduced derby uranium on the basis of over-all inclusion count. The hydrogen content in dingot uranium, however, was found to be appreciably higher than in either ingot or derby uranium.

A method was developed for calculating shield induced gamma radiation escaping through openings in a biological shield. The method was applied to the HRT and the results indicated that the contribution to the dose from induced activity in the HRT shield was around 0.1 r/hr and was insignificant in comparison to to other mechanisms contributing to the escape of gamma rays through shield openings.

Whenever fissile materials are handled in significant quantities such as in fuel element fabrication, separation processes, or in exponential and/or critical experiments a potential criticality hazard exists. The usual procedure which is followed by those persons conducting critical mass experiments is to either place the potential reactor in a heavily shielded cell or to conduct the experiments remotely in which case distance provides a measure of safety in the event of an unscheduled radiation outburst. In considering potential critically incidents, especially for the personnel not specifically engaged in critical mass studies, it is very likely that at the time of the incident neither the conditions of shielding nor distance will prevail for the personnel involved.

Abstract: A core design study of a 10 Mwe fast ceramic reactor is presented. Local reactivity coefficients, safety criteria, accident analyses, and economics are considered. An attempt is made to find a new balance of characteristics by purely geometric devices, i.e., by exploring the sodium : fuel ratio and varying the height : diameter ratio of the core. The use of BeO in the core was also investigated.

After two batches (~ 340 kg) of fluoride salt from the ARE were reprocessed, pilot plant operations were terminated because of a leak through which an estimated 780 g of uranium (as UF6) escaped. Of the 21 kg of highly enriched uranium in the feed, 93.12% was collected as UF6 product, 0.13% represented measured losses, and 3.72% was unaccounted for (leak). An additional 3.03% was reclaimed from NaF beds and equipment washes. The product met both chemical purity and activity specifications for product level UF6. Decontamination from fission products was essentially complete. A gross gamma D.F. was apparently limited by the low activity of the feed salt.

Many measurement of neutron spectra have been made in water assemblies. In these system a large part of the spectrum is given by an essentially Maxwellian distribution at the moderator temperature which is insensitive to the scattering model. Hence, the test of the energy exchange scattering kernel is in the difference of the spectrum and the fundamental or Maxwellian component. The figure shows the spectrum for the Nelkin model. Once the fundamental has been subtracted neither theoretical model seems to fit the data extremely well. Below kT the Nelkin model is a closer fit than the gas model but it underestimates the deviation from the Maxwellian whereas in the joining region it overestimates the distortion.

"In these studies ions of several-kilovolts energy were extracted from an ion source located inside one of the peaks of the mirror field...The extraction slot of the source is located near the field injection plane, about midway between the mirror peak and the center, and ions are injected perpendicularly to magnetic field lines. In their traversal of the distance between the mirrors, the ions are in an inhomogeneous magnetic field and have a component of velocity along curved field lines. This gives rise to a to a 'guiding center' drift in the azimuthal direction and prevents the particle trajectory from intersecting the ion source after the first reflection. The magnetic field is increased during the injection period by an amount sufficient to move the reflection surface inside the ion source region by the time the ions have precessed completely about the symmetry axis."

The following report deals with the application of the water boiler neutron source to the exponential experiments in an attempt to speed up lattice testing measurements.

The fact that material transport does occur under conditions of finite temperature difference in a flowing molten metal system was established. The rate mass transfer was thought to be either diffusion limited or solution rate limited. It is believed that the mass transfer of structural materials in Na or NaK systems is solution rate limited. The limiting process has not been qualitatively or quantitatively confirmed for the Inconel-Na or Inconel-NaK system. Increasing the maximum system wall temperature increases the amount of mass transfer, at least above 1300 deg F. The effect of the total temperature difference across the system on the amount of mass transfer was determined.

Abstract: Pure UO2F2 is made by reaction between anhydrous HF and pure UO3. Although it is difficult to prepare free of water, it is not very hygroscopic. Prolonged heating at 100-105 degrees releases 99.9% of the water in an aqueous solution; the rate of loss of water is very small after saturation is reached. X-ray diffraction data give a density of 6.2 for the solid. The density of a 1.004 M solution is 1.274; the density of a saturated solution (5.130 M) is 2.400. The densities of F-9 solutions have been calculated from the densities of ordinary aqueous solutions, and the values are compared graphically. Data on the solubility indicate that there is a small increase in the range 25-100 degrees. Recovery of pure F-9 from a solution is hampered by hydrolysis of U)2F2 to give HF. The HF may be held back by addition of UO3 or CaO; the use of the latter, however, makes more difficult the recovery of all the F-9. Molar conductivities of UO2F2 solutions at 25 degrees, as well as the specific conductivities of a 1 molar solution containing various concentrations of UO3, have been determined. The addition of UO3 lowers the conductivity. The low …