Seven runs were made with the system Penn. Ref. Co. "Supersol" (dispersed) water (continuous) to investigate the effects of pulse frequency, amplitude plate spacing, volume flow ratio, and throughput on backmixing, using the technique of continuous injection of a tracer solution into the packed section. Backmixing was found to be surprisingly insensitive to all the above variables over the range studied with the exception of pulse amplitude and continuous phase flow rate, showing greatest dependence on the later. Backmixing increased with decreasing continuous phase flow rate and increased with pulse amplitude.

The monitoring of thermal and resonance neutron flux in a thermal reactor having high flux over periods of time from 1 to 12 months using think Co foils is considered. Special attention is paid to the many correction factors to be applied to the activation data; neutron temperature, effective cadmium cutoff energy, burnout of Co59 and Co60, and decay of Co60. Results on a homogeneity test of 10 mil, 0.08% Co-A1 alloy foils is given.

The effects of oxidation and irradiation on the microsurface structure of pile graphite have been investigated by measuring the surface area and pore size distribution of several samples. The results obtained for both oxidized and irradiated graphite samples indicate that changes in surface characteristics which occur are determined by the flux, temperature of irradiation, and gaseous atmosphere in which the radiation takes place.

In connection with the study of aqueous-tributyIphosphate (TBP) systems, the study of the interactions of various diluents with the TBP has been extended. The diluents used were mineral oil, Amsco 125-90W, dodecane, n-hexane, cyclohexane, benzene, n-octyl bromide, carbon tetrachloride, chloroform and pentachloroethane. The solubility of TBP in water from solutions of these diluents and the solubility of water in the organic phase was determined. For the paraffin hydrocarbons as diluents the solubility of TBP in water was found to increase with increasing molal volume of the diluent. No evidence for the formation of TBP-water complex of simple mole ration was found.

A first iteration of the diffusion theory result is executed for the thermal flux distribution in a 7.5" graphite-uranium lattice cell using the integral equation formulation of transport theory.

The preparation of radioactive metallurgical specimens for microscopic examination is one of the responsibilities of the Radiometallurgy Sub-Unit. An abrasive cut-off machine development program, based upon a previous experimental model, was undertaken to provide a method for sectioning of irradiated materials without undue personnel exposure or spread of contamination and finally to provide data for the design of an abrasive cutting unit for use in the work cells in the Radiometallurgy Building. A horizontal-feed type set-off machine, powered by a 7 1/2 hp motor with V-belt drive, has been developed for the submerged sectioning of irradiated uranium and is currently being used successfully to obtain samples for metallurgical, chemical and physical investigations without excessive personnel exposure or spread of radioactive contaminates.

A laboratory test was performed to determine if a 10% oxalic acid solution could be safely be employed as a substitute to 2% chromic acid plus 5% phosphoric acid for removal of corrosion products from aluminum corrosion samples or slugs.

Ionization measurements of water vapor in vapor-liquid equilibrium were made with a series of chambers on a tritiated water sample which was prepared by burning T2 to T2O and diluting it with H2O. A correction was made for the difference of vapor pressures of HTO and H2O. The effect of HTO adsorbed on chamber walls and electrodes was eliminated from the final result. Using Gerbes data on the number of electron volts to produce an ion pair in air, agreement obtained between the measured source strength and the source strength as computed from pressure, temperature, volume, purity, and dilution data on the original gaseous T2 sample.

Plankton collected from the Columbia River by the net method and by the centrifuge method were compared. The centrifuged plankton (nannoplankton) exceeded the net plankton in weight, in abundance of organisms and in radioactivity. Similar seasonal trends were present in both types of plankton.

A pile gas leak detection system consisting of a purchased mass spectrographic type of helium detector, a long sampling line for use in remote or relatively inaccessable locations, a pump to pull a continuous sample of gas from the tip of the probe to the detector, and a rotameter to measure the gas flow rate in the sampling line has been developed, calibrated, operationally tested. The system is practical for use in locating all pile gas leaks larger than about 0.1 cubic foot per hour.

An analytical method for Cu-64 in reactor effluent has been studied based upon electrodeposition of the active copper with inert copper carrier. A two hour plating time was employed at a current density of 10 ma/sq cm and four volts across the cell. A stainless steel cathode plate was used. Carrier yields of greater than 80% were obtained with a standard deviation of the yield-corrected counting rate as low as 0.24%. Very little, if any contamination by other radioactive elements present was shown by decay curve studies. Self-absorption and self-scatter factors to correct the counting rate were obtained.

A continuous gamma-monitoring instrument capable of measuring the activity of the product of the Uranium Recovery plant has been developed and applied under process conditions. It has a detection limit of 15% and a normal range of up 1000% of the activity of natural uranium. Activity measurements made with this instrument have shown good correlation with laboratory determinations and are contributing to improved control of the solvent extraction process.

This report refutes earlier calculations made in the flux level of exponential piles. The results of the earlier calculations made on subcritical assemblies using critical assembly equations are in error. The calculations used in this report were more successful.

The approaches to the solution of the problem of removing or nullifying the effect of the hydrolysis of uranyl ion on acid titrations were: 1) use of a complexing agent and titration technique suitable for micro samples; 2) addition of a reagent that reacts with uranium to release 1 or 2 equivalents of acid per mole of uranium present (this permits correcting the titration value for the acid contributed by the uranium, or conversely permits an alkimetric titration of uranium); 3) separation of the uranium and acid with subsequent titration of the acid; and 4) direct titration of the sample with base. All these approaches yielded at least one method suitable for titrating acid in micro samples of uranium nitrate solutions.

This is the sixteenth quarterly report of the research and development activities of the Radiological Sciences Department, Hanford Atomic Products Operation, as before, includes some items charged to control but included for general interest. Such are identified as "not charged to research."

An experiment now in progress should give some accurate information about the thermal neutron absorption cross section of carbon 12. This report outlines and summarizes this experiment and analyzes it to determine the main sources of error and the probably error in the final result.

The gas commonly used in the chamber of the Simpson Proportional Alpha Counter (ASP) is the high grade, 99% pure methane. The cost of the gas has often raised the question of finding an adequate substitute and a number of substitutions have been attempted. Commercial methane has been substituted successfully for 99% pure methane and its use is recommended in ASP counters. Neither commercial nor technical methane caused any significant changes in instrument operation.

Many factors are responsible for the rapid growth of analytical chemistry during the past ten to fifteen years. One of the most important of these factors is the greatly increased significance to present day chemistry of many elements that in the recent past were principally chemical curiosities. Since the Atomic Energy program is concerned with many such elements, it is of interest to discuss the cause for this concern and the resulting effect on the field of analytical chemistry. A number of pertinent analytical research problems at Hanford will be cited as examples.

The purpose of the short duration corrosion test was to obtain preliminary data regarding the corrosion resistance of the spring steel wire in Purex process waste solutions and to measure any changes in the tensile properties of the wire resulting from this exposure.

Five continuous coatings were produced on zirconium coupons using an anodizing technique. These layers appear to be quite adherent and not subject to visible or audible failure caused by flaxion of the basis metal, Their abrasion resistance, though not investigated thoroughly, appears to be moderately good.

The results of this investigation indicate that maximum electric power generation can be obtained by selecting the turbine steam temperature within a range of plus/minus 30 degrees C. from an "idealized" steam temperature. This "idealized" steam temperature is shown to depend primarily on the maximum permissible uranium temperature. The minimum available condenser temperature and the temperature rise of the coolant in the pile effect the selection of the turbine steam temperature to lesser extent.

In connection with different seals for C & D equipment it appears advantageous that many parts could be made of rubber or other elastic polymers. However, data on the deterioration rate of these materials under irradiation are somewhat scant in the available literature. It appears that for neutrons and pure gamma radiation that a good grade of natural rubber stands up best in all the test reported and because the results of the neutron irradiation are so closely correlated with results from gamma it has been proposed that the principal source of damage is caused by secondary irradiation generated within the rubber by the neutrons.

Laboratory studies have shown that the double salt, CaF2-PuF4, can be precipitated by rapid addition of hydro-fluoric acid to solutions containing 25 to 75 g Pu/1, caleium equimolar to plutonium, and 1 to 10 M HNO3. The precipitate, which is subsequently washed with water and dried to 300 degrees C in dehumidified, deoxygenated argon, can be reduced thermally by calcium to give high yields of plutonium metal.

The conventional volumetric micro-determination of phosphate depends upon the precipitation of phosphomolybdate, filtration and washing of the precipitate, and titration with standard base. The method is slow and tedious, subject to many interferences, and is not applicable to samples containing less than 1-2 mg of phosphate. Other weak acid anions, such as carbonate or acetate, interfere in the method. Strong acid anions, such as nitrate, sulfate, and chloride do not interfere.