Thermal spikes occurring during the life of a slug in a pile cause a momentary destruction of the original configuration of atoms in the metal. This process occurs at such a rate that in a thermal neutron flux of 10(13) neutrons per square centimeter per second each atom in the metal will be subject to temperatures above the melting point of uranium every 40 minutes.

Removal of particles from air is discussed in terms of three classes of filtering media--air-sampling, respirator, and air-cleaning. Plots of efficiency versus filtering velocity are presented. The pressure drop characteristics of the filters are discussed in terms of initial pressure drops of the clean filters, variations in pressure drop of the individual filters, and comparison of loading rates.

In 1949 Barad presented two solutions to the general diffusion equation. Basic in both solutions is the assumption that in very stable atmospheres a point source may be replaced by a vertical area of uniform concentration at a short distance downwind. This vertical area is considered to exist at the distance at which the plume finally "levels-off" and assumes a flat ribbon-like appearance. In addition if the distance over which diffusion takes place is limited to one or two miles and if only the stable atmosphere with its narrow range of eddy sizes is considered, the average diffusion co-efficient (K) has a signficance which it does not have in the case of neutral equilibrium.

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.

The automatic polarograph is ideally suited for the analysis of waste streams for uranium in the Metal Recovery Process, and with modification, it is applicable to other processes, pilot plants, and even to laboratory set ups. The instrument is simple, dependable, and relatively trouble free in operation. It provides an immediate record of the uranium in the waste and, through better control of the process, lower processing costs.

Various non-linear calculations for heat conduction in an istropic, homogeneous medium are presented.

Feasibility of conversion of uranyl nitrate to uranium trioxide by the continuous addition of concentrated uranyl nitrate solution to hot, agitated UO3 powder.