At the present time, cerium-144 and premtheium-147 are the two fission product rare earths that appear most promising for use as the heat source in isotopic power units. Under proper conditions, cerium and the trivalent rare earths can be extracted from the Purex fission product waste stream as an insoluble sodium-rare earth double sulfate. A reprecipitation as the double sulfate, dissolution of the hydroxide, serves to give almost complete separation from the corrosion products, inert constituents of the waste, and from most of the fission products. The cerium and the trivalent rare earths must then be separated from each other. In the case of cerium recovery, it is necessary to remove the trivalent rare earths in order to maximize the specific activity of the cerium. If promethium is the desired product, a preliminary cerium separation is desirable to protect the ion-exchange resin (used for separating promethium from its adjacent rare earths) from the intense high-energy radiation from cerium.

Abstract. A neutron diffraction crystal spectrometer with a resolution of 13 microseconds per meter and monochromatic beam intensity up to 10(4)n/cm(2)=sec in the range 0.012-0.400 ev has been constructed for study of the activation cross section of Be7 as a function of energy in the thermal region. First preliminary results using ZnS(Ag) as a detector suggest the possibility of a resonance for the Be7(n,p)Li7 reaction in the region of 0.025-0.050 ev.

This report follows investigations of methods for sealing the ends of stainless steel-uranium oxide fuel pins with the objective to develop an end-capping method that would give consistently good-quality closures in production.

Photogeologic map of Stinking Spring Creek-15 quadrangle, Emery County, Utah

The following report discusses neutron sources in reactors, discussing general conditions of the study using a flux reactor.

Technical report with six sections describing the process: (1) The reaction of HN)3 with HSCN; (2) The distribution of nitric acid between hexone and water; (3) The distribution of HSCN between hexone and water; (4) The solubility of thorium sulfate in various extraction solutions; (5) The distribution of protoactinium and fission elements between hexone and aqueous thiocyanate solutions; and (6) Separation of uranium from thorium by extraction into hexone as UO2(SCH)a.

Stresses set up by an insulating strip in the bond are estimated and found to be small compared to those normally present without the defect.