From introduction: This report is a technical evaluation of four reactor power plant designs proposed by various AEC contractors.

The spontaneous fission rate of plutonium-240 has been redetermined and found to be 1.51 X 106 events/g/hr.

Hanford uranium contains minute angular inclusions which affect the microstructure, reactivity, and other important factors controlling the serviceability of the metal. Small quantities of the inclusions have been isolated by chemical means, and the x-ray diffraction patterns and chemical analyses of the isolated materials have been determined. As a first step in the identification of the inclusions present in rolled uranium, a search was made for a chemical method of separating the inclusions from the matrix metal.

The construction and operation of a fission gas generator, containing about 25 grams of uranium in the form of a powder with a high specific surface, are described in detail. The purpose of the work discussed in this report was to examine the feasibility of producing, separating, and assaying samples of Xe135 in preparation for a proposed measurement of the neutron cross section of this isotope. Krypton and xenon are separated by selective adsorption on charcoal at reduced temperature while iodine is removed by charcoal sorption at room temperature.

From abstract: "The circumstances are described pertaining to an explosion in a TNX evaporator during the concentration of a uranyl nitrate-nitric acid solution. TBP and Amsco diluent were probably present in the evaporator charge. A laboratory program involving small-scale atmospheric and closed-vessel distillations of various mixtures of UNH, HNO3, Amsco, TBP, and water indicate that an exothermic reaction between TBP and UNH, or between TBP and HNO3, or both, was responsible for the explosion. The danger areas of temperature, TBP concentration, pressure, and heating rate are defined and recommendations are made for safe evaporator operation.

In the course of recovering uranium from Rand cyanide residues, large volumes of barren acid liquors are produced. With the flowsheets now under consideration it is not advisable to recycle such liquors and they are to be discarded. Consideration was given to the removal of manganese under conditions that would permit its recovery as MnO2.