Abstract: "Detailed consideration is given to some properties of the first excited electronic state. Following the analysis proposed bv Mulliken, SCF LCAO-MO coefficients are used to obtain qualitative information about the electron distributions. Comparison is made with earlier work with respect to the description of the excited-state dipole moment, the effective electric moment between the ground and excited states is also calculated. From this, the oscillator strength for the first allowed transition is computed as a function of the internuclear distance."

In recent months, relatively large quantities of neptunium-237 have been recovered from Hanford irradiated uranium. The over-all recovery process consisted of 1) isolation from Purex plant solutions by solvent extraction, to yield an impure neptunium nitrate solution contaminated principally with uranium, plutonium, and fission products (2) purification by anion exchange 3) precipitation of neptunium (IV) oxalate; and 4) calcination of the oxalate to yield neptunium (IV) oxide, NpO2. This paper describes the oxalate precipitation process investigations and results.

Abstract: A study was made of the reactions of nickel dipivaloyimethide with the following reagents: tirphenylmethyl chloride, benzoyl chloride, [rho]-chloro and [rho]-methyl benzoyl chloride. Infrared spectra of the easily hydrolyzed product of tritylation seem to indicate that enol ether, the product of O-alkylation, is formed. the acyl halides reactor to give the triketones. the latter have been characterized by spectra and C, H, analysis. the kinetics of all the reactions studied were found to settle down to a second order rate law after a fast initial reaction. These reactions are catalyzed by an impurity in the acyl chloride. Then benzoyl chloride with a different purity was used, the second order rate constant for the benzoylation of nickel DPM ranged from 0.02-0.20. The air oxidation of nickel dipivaloymethide was found to compete with the acylations under the conditions of these studies. An investigation of the phenomenon showed that nickel pivalate is the major product. Pivalic acid was also detected in the product mixture. This oxidation takes place in chlorobenzene and in aromatic hydrocarbons. It occurs in 1201 when small amount on benzoyl chlorides are present.

Current regulation of a Bitter type electromagnet powered by a 10 kw. motor-generator set has been achieved by control of the generator exciting field. An error signal, obtained by comparing the voltage drop across a series resistor in the magnet circuit with a reference voltage, is fed back with appropriate amplification to the grids of series tubes in the generator field supply. Magnetic fields from 400 gauss to 10 kilogauss in a fixed gap (1.5 in. width and 3.5 in. diameter) are obtainable with regulation to 3 parts in 104 over the major part of this range.

This technical report covers five areas: (1) High-speed computer program; (2) Mathematical methods; (3) ILLIAC use and operations; (4) IBM 650 use and operation; (5) General laboratory information.

The Single Tube Prototype Mockup (STPM) was constructed to be used as a tool to evaluate the mechanical problems involved in operating and maintaining many components of the Plutonium Recycle Test Reactor (PRTR). This report has been written to acquaint interested HAPO components with the capability of the STPM and for use as an aid in scheduling tests and/or to properly evaluate testing results obtained from the mockup.

This report summarizes the research and development work carried out during March, April and May, 1959, for Budget Activity 2790 - Separations Development for Non-Production Reactors, The effort on Activity 2790 will enable Hanford to begin reprocessing in January, 1962, the fuel elements from power reactors which employ depleted or slightly enriched uranium fuels.

The 300A and loop were operated for 2862 hr with thorium oxide slurry at 1500 psi and 280ºC to determine the effects vane inlet and exit geometries on impeller wear, the wear rate of aluminum oxide bearings in this size pump, and the operating characteristics of the loop. The thoris, a 1600*C-fired oxide, had a mean particle size of approximately 2 u. Average circulating slurry concentration was approximately 450 grams of thorium per kilogram of water and average flow rate was approximately 300 gpm.

The hazards associated with several possible mechanical failures were analyzed for the PRTR. The consequences of these failures were evaluated for inclusion in the Final Hazards Summary Report.

Several tests are being performed and others being planned to investigate the role of heat transfer in corrosion processes. These tests are measuring both corrosion rates of metals (Zr-2 and X-8001 aluminum) under heat transfer, and the temperature rise associated with the buildup of the corrosion product. A brief description of these tests is given in this report.

The rate of uranium sorption by a strong-base anion-exchange resin (Dovex 21K) from a uranyl sulfate solution (U 0.005 M, H2SO4 0.02M, SO4 0.2 M) was studied using a stirred vessel technique and measuring the U235 gamma radiation on each bead. Resin initially in the chloride form and the sulfate for was studied.

A method for determining the concentration of Li6 in aqueous solution has been tested using the nuclear reactions Li6 (n,α)H3 and O16 (H3,n)F18. Annihilation 7 radiation of induced 1.87 hour F18 radioactivity was counted with a well-type scintillation counter, and the radioactivity per millimole of lithium was found to be independent of lithium concentration below about 0.2moles/liter. The sensitivity limit for detecting lithium is less than 0.1 micromole (0.0075 micromole Li6).

In an earlier study on criticality conditions for homogenous mixtures, 2/cm^2 was used as the neutron age for all mixtures of water and uranium. At the higher H/U ratios (low uranium concentration), the calculated critical parameters were in good agreement were in good agreement with experimental data. At the low H/U ratios (high uranium concentrations) the calculated critical parameters were smaller than the experimental ones (more conservative from a nuclear safety point view). These results indicated that using 27 cm^2 as the neutron age gives increasingly conservative results as the H/U ratio decreases.

The measurement of a alpha-particle energy has been used by many radiochemical laboratories for the identification and analysis of alpha-active radio nuclides. The use of the total-ionization method for alpha-active radio-nuclides. The use of the total-ionization method for alpha energy in ionization chamber in which the alpha particle loses all its energy in ionization of the chamber gas. Collection of the electrons thus formed generates a voltage pulse across the chamber capacity which is proportional to the alpha particle energy. This pulse is then amplified using a suitable linear amplifier and fed to a pulses as to amplitude; the information is then recorded or stored. Since the pulse amplitude is proportional to the alpha energy lost to the chamber gas, the pulse height analysis can be used to estimate the energy of the alpha particles and in the case of several alpha emitters of different energies, the relative abundance of the alpha emitters can be determined. An alpha energy analyzer system using the ion collection method has been fabricated for use in radiochemical laboratories required to perform a large number of alpha energy determinations. This report describes the operation, maintenance, and application of this alpha energy analyzer system.

High heat flux electrical cartridge heaters were tested with direct air cooling under simulated ORR Loop conditions. The cartridges and the heater design were found to be satisfactory. A gas cooled of concentric pipe design utilizing air, water, and air-water mixtures as the coolant was also evaluated and found to be satisfactory.

The nuclear safety portion of this report is inclined to ignore the factors by which safety limits can be increased. It makes no mention of the control that can be exercised by limiting the assay of the U-235 being processed in the plant. From some of the previous reports, it is apparent that this plant is not anticipating processing U-235 of assay greater than approximately 20%. At this value, many of the numbers that are presented in the tables could be increased markedly. Rough examination indicates that these values all refer to top product U-235. The general discussion is, however, excellent. The references apparently used are those unclassified references with which we are all familiar and think highly of. We would recommend the inclusion of TID-7016.

From abstract: "The toxicological properties of beryllium and compounds of beryllium are briefly reviewed, together with the historical development of the recommendations for maximum permissible beryllium air concentrations. The application of the enclosure technique presently in use at this laboratory for the control of beryllium hazards is described... Monitoring procedures used to evaluate the performance of enclosures are discussed."

Preliminary experiments have been conducted to evaluate the use of the nuclear reactions Li6 (n,α)H3 and O16(H13,n)F18 to determine the thickness of oxide films on metals. Sheets of thin paper and of aluminum, imbedded in powdered LiF, were irradiated with pile neutrons at a flux of 6 x 10^11 n/cm^2/sec and counted with an end-window proportional counter. A saturation activity of 1.87 hr F18 of 150 dis/min per microgram of oxygen was observed in the paper, but radioactivity due to impurities masked F18 in the aluminum. It is concluded that a 1 A (0.01 μgm/cm^2) oxide film thickness may be measured by a neutron irradiation at a flux of 10^14 n/cm^2/sec but chemical separation of induced radioactivity from the bulk metal is essential.

Basic Studies. Sinterability experiments in the system UO2-PuO2 have continued, and data are available at one hour hold times across the UO2-PuO2 composition limits. Sintered densities appear to be markedly dependent on pressed densities with densification occurring very rapidly at higher pressing pressures. The following table illustrates the effect of one hour at temperature on final density for pure plutonium dioxide pressed to both 40 and 60 percent of theoretical density.

Experimental test loops have been used to study the problem of hydraulic stability. The oscillatory behavior of a single-phase and two-phase natural circulation loop has been examined at atmospheric pressures and oscillating modes of operation were studied in terms of heat input.

Three edge loaded thoria-urania nuclear fuel samples were assembled into a capsule, irradiated and examined. This irradiation was the first of a series to develop thoria-urania fuel for high heat flux, specific power and burn-up operation in a sodium graphite reactor.

The recovery of plutonium and neptunium by anion exchange has been well demonstrated on a laboratory scale. (1, 2,3,4) The specific adsorbed by the resin is the tetravalent hexanitrate complex of either element. With plutonium (IV) and neptunium(V) in IWW, the plutonium is adsorbed but the neptunium is not. If nitrite is used as the reductant in strong (preferably 8 M or over) nitric acid, both plutonium and neptunium are obtained in the tetravalent state, and both are adsorbed on the resin. With stronger reductants, such as semi carbazide or ferrous sulfamate, plutonium (III) and neptunium (IV) are obtained so that only the neptunium is adsorbed. Optimum recovery of either element is obtained with between seven and eight M nitric acid.

"Centrifugal-casting techniques were investigated as a method of producing hollow cylindrical extrusion billets of aluminum-35 w/o uranium. Among the variables evaluated were melt temperature, mold and pouring-spout configurations, mold speed, and method of pouring. With the equipment employed it was found that the best castings were produced stilizing a pouring temperature of 2400 F, a heavy-walled steel cylinder rotating between 700 to 900 rpm for the mold and bottom-pouring technique employing a retractable pouring spout. Sound, nonporous billets 26 in. long and 5 in. in diameter were produced with a yield after machining of over 75 per cent of the original charge. The major losses occurred in the pouring spout-and-cup assembly. This loss is relatively unaffected by the casting length; and, therefore, coatings of greater length than 26 in. should results in even greater recoveries.

Relatively long time cycles are required for the standard nitric acid dissolution of enriched uranium using safe batch size techniques for criticality control. Upwards of forty eight hours are required for the total dissolution of solid of I and E enriched slugs in nitric acid. The dissolution capacity may be increased by: (1) using a dissolver critically safe by virtue of its geometry or, (2)increasing the rate of uranium dissolution. Dilute agua regia -- a mixture of hydrochloric and nitric acids -- is known to dissolve uranium much more rapidly than nitric acid. This reports present a flowsheet for the rapid dissolution of uranium slugs in dilute agua regia.