Several improvements have been made in the gamma scintillation counter (GSC). The Model V gamma scintillation counter uses a canned thallium activated sodium iodide crystal as a detector. Although the electronic components remain unchanged, a modification of the sample support has been made to improve reproducibility of geometry. To assure comparable results between various counters, they must be operated at the same energy threshold and counting yield. Methods have been developed to assure operation at a preferred energy threshold of 0.1 Mev and an arbitrarily fixed counting yield of 3.36% for Cs-Ba-137. Partial pulse height discrimination against U 237 is also accomplished.

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 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.

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.

Experimental data pertinent to the evaluation of hazards involved in the exposure of personnel to tritium and tritium oxide are reviewed. Conclusions are drawn and recommendations made with regard to the control of these hazards.

Foils of plutonium 239 and uranium 235 have been mounted back to back in a dual ionization fission chamber in the diffracted beam of the Hanford neutron crystal spectrometer. A quantity proportional to the ration of fission cross sections of Pu239 to U235 has been measured as a function of neutron energy from 0.020 to 1.0 electron volts. The results of this investigation are presented graphically in the text.

The prompt administration of zirconium citrate was at least twice as effective as the prompt administration of calcium disodium salt of ethylenediaminetetraacetic acid (CaEDTA) in preventing deposition of plutonium in the skeleton. On the other hand, CaEDTA was twice as effective as zirconium citrate in preventing the deposition of plutonium in soft tissues. The combined administration of zirconium citrate and CaEDTA was the most effective treatment for preventing the deposition of plutonium in the total rat. Zirconium malate offered no advantage over zirconium citrate, and appeared to be somewhat more toxic. Three doses of the zirconium salts over a four-day period were no more effective than a single dose.

The feasibility of using Teflon bellows as the pulsing device for solvent extraction pulse columns has been previously demonstrated by life test of various sizes of Teflon bellows. This report describes a compact Teflon bellows pulse generator and drive assembly which was designed, built, and tested by the Chemical Development Unit. The pulse generator assembly is suitable for a number of applications where pulse generators are required to pulse solvent extraction columns.

Report describing the Hanford Plutonium Recycle Test Reactor (PRTR), its building, safety procedures, site, operations, and analyses of its safety features.

Report documenting the Halogen Collector Test program, which was undertaken to provide "methods of removing trace quantities of radioactive iodine from an air stream" (p. 1). The report includes designs of the program and the test facility, test results, analysis of these results, and encountered problems. Appendices begin on page 38.

Gamma scintillation monitor Model 3 is designed to continuously monitor and record the gamma activity of a process solution.

Report that presents and interprets data taken from previous tests involving gas-lift circulators and then correlates the data for the purpose of design and operational improvements.

From introduction: "This report provides background information regarding the study results presented in the first volume of this report and provides information resulting from the studies made on the gas cooled reactor concept."

Study of factors, such as the average particle size and particle-size distribution, which affect the fluidization properties of uranium trioxide powders.

From objective: "The objective of this work was to design, develop, assemble, and test and automatic analyzing monitor for recording the prominent isotopes in reactor effluent cooling water."