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.

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.

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