From abstract: "This report describes and evaluates the variables affecting contamination of precise devices...In the present report these variables are discussed in more detail and the basis for their inclusion in the listing are given. The relative importance of the several parameters will be discussed in another report."

A Lucite model of a multi-stage countercurrent hydroclone solvent extraction apparatus has been constructed and tested with Amsco-water. The diffusivity of Cs 134 tracer in aqueous chloride solution was measured to check the performance of the capillary diffusivity measuring system. The experimental data from four Druhm runs showed that 1/8in. thick graphite liners are usable for reactor temperatures above the boiling point of sodium.

Abstract: The removal of both SM-1 Core I high burnup elements from the SM-1 Core II and the insertion of two SM-1 Core I spare elements i their places are discussed. Nuclear and thermal characteristics of Core II with the change are presented and conclusion related to the change in hazard potential are made. If the core change indicated by this report is made, local peaking factors will be decreased and burnout ratios will be increased. This, of course, in itself leads to a more conservative estimate of core safety. There is no conceivable reason why this perturbation may not be safely made in the SM-1 Core II.

A commercially available electronic high vacuum pump has bee tested on various types of mass spectrometers used at the Oak Ridge Gaseous Diffusion Plant. Considerable savings in operating and maintenance costs can be realized from the use of this pump. the greatest savings result from the elimination of the cold trap required for the diffusion pump whether it is cooled by liquid nitrogen or by mechanical refrigeration. additional savings results from the fact that the pump currently is usually an adequate indication of the pressure in the spectrometer tube and that a continuously running mechanical fore pump is not required.