Abstract: "The critical mass both of an untamped and water-tamped sphere with parabolic radial variation of the intrinsic buckling is calculated by a perturbation method. The result is applied to finding the minimum critical mass of plutonium in water suspension with infinite water temper; the calculations show that the minimum critical mass at constant concentration may be reduced by an amount of the order of 7.6% when the concentration of plutonium is permitted to vary throughout the suspension."

We consider here the accuracy of relaxation lengths measured during the water-uranium lattice experiments. Since such an analysis for all measurements would take a great deal of time, we have applied it to just one lattice. This one (2:1 water-to-metal ratio) was chosen completely at random.

A wet collection system for aerosols has been developed using fibrous media. Tests show the performance to be in accord with recently developed theory of collection by fibrous media. The effects of varying aerosol particle size, particle density, and gas velocity have indicated that inertial impaction is the primary collection mechanism. Three-year operating experience on several full scale plant installations shows reliable performance.

As part of an investigation of solvent stability, a direct analysis of recycled Uranium Recovery Plant solvent* has been made to determine the type, source, and properties of the impurities which have been generated in the solvent and are present in the solvent after it has been in use for some time. This work has been directed towards the separation and identification of the impurities by compound class, and the conclusions are set forth in this report. Another purpose of this report is to present the separation scheme employed, which will likely find similar application.

Eight zirconium and eight Zircaloy-2 process tube samples were irradiated in the "H" test loop, Tube 0961-H, so that the corrosion tendencies of the material might be evaluated when exposed to radiation. The samples were delivered to the Radio-metallurgy Building in January, 1955, and examined as requested by C. D. Wilson of the Pile Development Unit, Pile Technology Section.

Pressurized water nuclear reactors may be designed based upon either of two concepts: (1) pressure vessel, wherein the entire core is placed in a large, high strength fuel channels within a low pressure container. The Plutonium Recycle Test Reactor is a pressure tube type reactor. Selection of this basic type of pressurized water reactor depended to an appreciable extent upon the availability of suitable pressure tubing.

This bibliography contains 94 references on metal hydrides, with particular emphasis placed on the hydrides of titanium, yttrium, and zirconium. The bibliography covers the period 1955 through 1959. The references are arranged alphabetically by title. Sources used in compiling this bibliography are: Applied Science and Technology Index, Abstracts of Classified Reports, ASM Review of Metal Literature, Bibliographies of Interest to the Atomic Energy Program, Classified and Unclassified Parts, Industrial Arts Index, Internal Card Catalog, Monthly List of Bibliographies in the Atomic Energy Program, U.S.A.E.C. Technical Information Service Extension, Nuclear Science Abstracts.

Calcination of liquid radioactive wastes, the process of converting metal nitrates and sulfates to oxides by heat, is under development at Hanford as a means of reducing these liquids to a dry powder or solid which can be stored safely. Radiant-heat spray calcination, one of the methods under study, was first investigated at the Oak Ridge K-25 Plant (1) as a possible method of calcining uranyl nitrate to uranium trioxide. The process has also been under extensive development at the Pulp and Paper Research Institute of Canada (2) and is designated by them as the Atomized Suspension Technique.

In previous letters we have reported a Av resonance, called Y*1, observed through the study of the interaction of 1.15-Bev/c K* mesons in hydrogen in the Lawrence Radiation Laboratory 15-in. bubble chamber. We now wish to report the results of the study of the three reactions [formula](1), [formula](2) and [formula](3).

Abstract: "Experimental investigation of aerosol particle capture by evaporating and condensing water drops has shown that capture is a function of the rate of water drop growth and aerosol particle diameter. Capture was found to be proportional to the rate of water vapor condensation and inversely proportional to aerosol particle diameter. The influence of water vapor gradient and particle size on aerosol particle capture during evaporation is insignificant. The experimental results are explained on the basis of particle penetration through the boundary layer of a water drop. An analysis of previous research on radioactivity of dry particulate matter in an urban atmosphere is included."