Laboratory studies have shown that the double salt, CaF2-PuF4, can be precipitated by rapid addition of hydro-fluoric acid to solutions containing 25 to 75 g Pu/1, caleium equimolar to plutonium, and 1 to 10 M HNO3. The precipitate, which is subsequently washed with water and dried to 300 degrees C in dehumidified, deoxygenated argon, can be reduced thermally by calcium to give high yields of plutonium metal.

Thirty gram patches of plutonium dioxide can be readily chlorinated by reaction with phosgene or carbon tetrachloride at temperatures of 350 and 450 C respectively. Plutonium trichloride prepared by either method can be reduced to the metal in a hermetically sealed bomb by reaction with calcium. On a twenty gram scale yields of approximately 97 per cent are obtained when a calcium-iodine booster is employed. It has been demonstrated that a method for reduction of plutonium trichloride to the metal without the use of a booster can be development.

Foils of plutonium 239 and uranium 235 have been mounted back to back in a dual ionization fission chamber in the diffracted beam of the Hanford neutron crystal spectrometer. A quantity proportional to the ration of fission cross sections of Pu239 to U235 has been measured as a function of neutron energy from 0.020 to 1.0 electron volts. The results of this investigation are presented graphically in the text.

Unanticipated radioactive contamination of the 200 Areas environs was discovered in the latter part of 1947, about 2.5 years after the startup of the Bismuth Phosphate Separation Plants. It was subsequently established that this contamination was due to radioactive particles emanating from the Separation Plants' stacks, and the need for exhaust ventilation air filtration equipment was recognized. Sand filters were installed in the fall of 1948 in the ventilation systems of the B and T Bismuth Phosphate Plants. These filter units essentially eliminated this contamination problem and have performed satisfactorily to the present time.

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.

Many procedures for the chemical isolation of the microscopic angular inclusions in rolled uranium have been investigated. Four were selected as most satisfactory for this work and will be described in detail. The procedures are: (1) the copper displacement of the uranium, (2) the electrolytic displacement of the uranium, (3) the chemical dissolution of the uranium in an anhydrous solution of hydrogen chloride in methanol, and (4) the chemical dissolution of the uranium in an aqueous solution of hydrogen chloride and hydrogen peroxide.

Supervision and coordination of shutdown work are often made difficult by lack of visual contact between the front face, rear face and control room. Examples of such conditions are: Removal of process tubes, where close co-separation between front and rear elevator crews is required; Locating freshly discharged slugs accidently lodged on discharge face obstructions where radiation levels are high and optical viewing equipment inadequate; Monitoring of the transfer of hot samples from a process tube into a cask, where permissible exposure time is short and oral briefing of personnel who must perform subsequent operations is inadequate.

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

This document is a sequel to HW-30226, "Steady State Temperature Distribution in a Solid Slug." A primary feature of the present as well as the former paper is a treatment of the stand heat flow equation in a manner which accounts accurately for the dependence of the thermal conductivity, K, on temperature, v.

In view of the increasing number of methods for determining plutonium in terms of weight rather than radioactivity, a need has arisen for a plutonium compound that can be used as a gravimetric standard. An easily prepared compound that dissolves readily in nitric acid is desirable. The present study was made to determine the feasibility of using plutonium triflouride as a plutonium standard. The preparation, composition, stability, and ignition of the compound are discuss, as are certain properties of the plutonium dioxide resulting from ignition of the trifluoride.

The very strong flux gradient in the MTR reflector might be thought to be some cause of worry. However, this gradient will be minimized by the presence of the large block of aluminum, which, because of its small effect on neutrons, will tend to flatten the neutron flux in its vicinity. Advantage should be taken of the shape of the test facility by placing the water hole corner closest to the MTR core. This placement should take best advantage of the flattening potentialities of the slowing-down flux from the test slugs, by placing the nearest (beryllium) moderator on the low flux side of the assembly.