"Abstract: Data on analog magnetic tape characteristics are presented along with results from conventional and modulator playback system operational tests. Theoretical considerations imply that the modulator head should be loss sensitive to short term variations in record and playback tape speed. It is also pointed out that although a tape recorder operating at 7.5 in./sec has only 12 kcs bandwidth for sinusoidal wave forms. the record and play-back amplifiers for pulse recording can operate with other bandwidths. These amplifiers must be capable of passing a square wave with a frequency of 1.5 kcs. A square wave of such frequency represents the condition of 350 microsecond pulses with a 700 microsecond period. (J.R.D)."

Report discussing the equations of the Debye-Huckel theory modified to include quantum statistics.

The following report proposes a concept of a transient version of Astron thermonuclear reactor while describing the basic concepts of the reactor and the design criteria.

Report discussing the application of some previously established methods to yield a calculation of the pressure and internal energy functions of a system of point charges interacting only with Coulomb forces.

The nuclear safety portion of this report is inclined to ignore the factors by which safety limits can be increased. It makes no mention of the control that can be exercised by limiting the assay of the U-235 being processed in the plant. From some of the previous reports, it is apparent that this plant is not anticipating processing U-235 of assay greater than approximately 20%. At this value, many of the numbers that are presented in the tables could be increased markedly. Rough examination indicates that these values all refer to top product U-235. The general discussion is, however, excellent. The references apparently used are those unclassified references with which we are all familiar and think highly of. We would recommend the inclusion of TID-7016.

Technical report of an investigation to determine a suitable material for sintering and casting of braze rings. Braze rings afford an excellent means of preplacing braze alloy on tube to head joints of radiators, heat exchangers, and similar applications. A cast ring is especially desirable because of its increased strength. Previous efforts at casting had used welding grade carbon blocks with the desired ring cavities machined into their surface. Conclusion: Stackpole grade 331 electro-graphite provided the best results of the materials investigation. It is hard and more readily machinable with conventional tools than other grades. Carbon, in general, proved to be more satisfactory especially due its ease and speed of fabrication.

In support of an in-reactor thermocouple stability testing program now in progress, laboratory studies were made relative to the stability of thermocouple bundles similar to those projected for in-reactor use. Two sets of chromel-alumel, copper-constantan and iron-constantan thermocouples were held for extended periods at 300 C in successive atmospheres of 75% helium-25% carbon dioxide. 100% carbon dioxide and air. Thermocouple stability was verified by measuring emf's at the freezing point of lead. The results of these tests are to be used to evaluate data obtained from like thermocouples subjected to condition similar to the laboratory tests with the added facet of reactor irradiation.

Maximum safe cylinder diameters, slab thicknesses, and minimum critical masses in spherical geometries for fuel of < 5.0& U-235 enrichment have been evaluated. It is of interest to know the minimum critical masses as a function of cylinder diameter for vessels that are not safe by geometry. Curves will be presented of critical masses as a function of cylinder diameter and fuel rod size for 1.6%, 3.0%, and 5.0% U-235 enriched metal-water systems.

Neutron radiation can be greatly reduced by substituting plutonium trichloride for plutonium tetrafluoride in the dry chemistry step of metal preparation. Chloride processes are now common in the metal preparation industry, and the 234-5 Developmental Laboratory has shown plutonium trichloride can be satisfactorily prepared and reduced to the metal.

The system Dovex 21K and aqueous uranyl sulfate solutions were studied in the solution compositions range: 0-0.005 mol/liter uranyl sulfate, 0.15 mil/liter total sulfate, 0.02 mol/liter H2SO4 (pH 2).It is shown that UO3SO4 and/or UO2(SO4)2-/2 are sorbed on the resin to form R2UO2(SO4)2. It is surmized that these same species are also involved at high uranyl concentrations and pH 2 it is suggested that U2O5SO4, U2O5(SO4)2-/2, and R2U2O3SO4 species may be involved.

The purpose of the test was to insure satisfactory operation of the turbine after overhaul of the turbine which was completed February 1, 1959. The operation of the turbine during this start-up was satisfactory.