In the Columbia River downstream from Richland, Washington there is a gradual decrease in concentration of radioactive isotope. At any one location there are fluctuations due to factors such as dilution and decay time. During this period at all locations the concentration of alpha particle emitters in water averaged below the detection limit. Beta particle emitters in water upstream of McNary Dam decreased slightly due to increased river flow this quarter, with averages at various locations. Downstream from McNary Dam, beta particle emitter average concentrations in water were about the same as the past three quarters.

Hydrogen peroxide has been used to reduce plutonium (VI) in nitric acid solution to the (IV) valence state. However, reduction of plutonium (VI) solutions containing iron has often been incomplete when hydrogen peroxide was used as the reducing agent. Since reduction of plutonium (VI) has been applied in plant solutions containing iron, a study of the plutonium (VI) reduction with hydrogen peroxide was undertaken. Variables tested included plutonium, nitric acid, and iron concentrations.

The creep problems associated with zircaloy-2 process tubes and the factors affecting the creep of these tubes were discussed in detail. Emphasis was placed on the determination of the tube wall thickness for an SPR tube, whose minimum thickness is limited by creep considerations. It was concluded that, at the present time, there is not enough information available to design zircaloy-2 process tubes on a realistic basis. Various experiments were suggested to supplement the creep rate testing program being pursued by Battelle Memorial Institute.

The experimental evaluation of low (10⁻⁸ in/in/hr) creep rates are costly and time consuming. Thus, in answer to a request from the design group, the creep data on Zircaloy-2 obtained at Battelle Memorial Institute is extrapolated into the low creep rate range. Because the methods of extrapolation have not been evaluated at very low creep rates on Zircaloy, two different methods are used to analyze the creep data. The methods of extrapolation are given so that future analyses can be carried out by the design group or by other sections interested in predicting creep rates which have not been experimentally determined.