The following report provides information conducted during histological observations made on the anatomy of female mice who have been exposed to 400 arbitrary units of slow neutrons.

This quarterly progress report details ongoing work at the Oak Ridge National Laboratory as part of the Aircraft Nuclear Propulsion Project. Topics of discussion include reactor theory and design, shielding research, materials research, appendixes with information on ongoing analytical chemical studies.

Abstract: An analysis of the lid tank neutron data for Pb-H2O and Fe-H2O is made. "Effective" fast neutron cross sections for the metals are obtained. This is based on the "one collision theory" of shielding. Values are 3.4 barns for Pb and 2.0 barns for Fe. These compare very well with those obtained by Albert and Welton based on other lid tank data and another method of calculation.

As there is no accurate measurements of the energy distribution of neutrons emerging from large uranium blocks, it becomes of importance to see how much information of this kind can be derived from the slowing down distribution of the neutrons in a water tank.

Introduction. the conventional procedures of analysis for uranium and manganese can be employed in the analysis of alloys of these metals. The alloys are reacted with perchloric acid and hydrogen peroxide, fumed to remove any chloride ions, diluted to volume and aliquots analyzed by redoximetry.

From introduction: "The concluding remarks of the report on the electron diffraction study of UF6 suggest two alternate explanations for the apparent discrepancy between the structure proposed for this compound as deduced from X-ray diffraction work on single crystals and from the electron diffraction investigation of the vapor. The second explanation is based on the premise that the difference may be due to essentially unlike methods of treating the diffraction data. In this report we shall analyze X-ray powder photographs following a scheme parallel to that used in the analysis of the electron diffraction data, to check whether this particular explanation is tenable."

Abstract: An analysis of SM-1 Core II and SM-1A Core I zero power experiments was made by comparing these cores to each other and to AM-1 Core I on the basis of critical bank positions, bank calibrations and available chemical analyses of the fuel plate compositions. The effects of replacing boron absorbers by europium absorbers upon rod worth and stuck rod conditions were studied. Comparisons of measured and calculated power distributions were made. It was concluded that both SM-1 Core II and SM-1A Core I contain nearly identical B-10 loading of 17.79 grams, compared to the best estimate of 15.75 grams for SM-1 Core I. The available data indicates that all three cores possess similar nuclear characteristics.

From abstract: "Using the method of induced radioactivity, the capture cross section of Pb[^]208 for C neutrons is found to be .00045 ± .00015 x 10[^]-24 cm[^]2. This is definitely lower than the value of .001 x 10[^]-24 reported by Maurer and Ramm."

The following report describes the methods of chemical conversion of uranium fluoride to uranium trioxide.

From abstract: "This report describes the decontamination of Oak Ridge National Laboratory Purex Pilot Plant facilities and presents an appraisal of the decontaminating techniques and reagents which were employed."

A resin-in-pulp process was developed using a series of fixed-screen or Winchester cells. Various laboratory and pilot plant models were constructed and tested under simulated plant conditions. The fixed-screen device proved very effective in the recovery of uranium and/or vanadium by a continuous, resin-in-pulp process.

The work described in this technical report was undertaken as part of a larger program dealing with a systematic investigation of changes in the physical prosperities of artificial graphite due to neutron bombardment. Very pronounced among those changes is the increase in the elastic modulus. Since there is a general relationship between the elastic modulus of a given substance and its specific heat, it was expected that corresponding changes will occur in the specific heat. In conclusion, the experiments determined that it appears that the low temperature specific heat measurements of strongly bombarded samples will be helpful for the understanding of the nature and the mechanism of the changes produced by neutron bombardment and annealing.

Cycle study performed on a closed loop Brayton cycle incorporating a gas-cooled nuclear reactor, regeneration, and compressor intercooling. The purpose of the study was to determine the effect of various cycle parameters on efficiency and cost.

From abstract: "Resistivities of solid solution alloys in the systems Gd-Lu, Tb-Lu, Gd-Er, and Y-Lu were measured from 4.2-320°K to determine the behavior of the resistivity in alloy systems with magnetic phenomena arising from localized magnetic moments. A large contribution to the residual resistivity is caused by the random distribution of these localized moments through the lattice. An analysis of the lattice resistivity of the metals shows large variations across the heavy rare-earth series which are possibly correlated with the change of c/a ratio of the metals and the attendent changes in the Fermi surface geometry."

Abstract. The separation of uranyl nitrate from aqueous solutions of 0.635 M thorium nitrate, 3 M nitric acid and 3 M calcium nitrate by extraction with organic solvents has been investigated. Solvents which gave good separations were 2-tthyl hexyl acetate, ethyl benzoate, n-butyl either and beta-beta- dichloroethyl ether. In general, higher esters, ethers and alcohols are better for separating uranium from thorium that the lower homologues. Several solvents were tested at lower nitric acid concentrations. Dibutyl cellosolve gave a very good separation when the solution was 0.1 M nitric acid. Of the solvent mixtures studied that of equal parts of n-butyl ether and dibutyl cellosolve gave a good separation.

Information on experimental facilities and reactors.

The following report analyzes various experiments made to discover factors that may affect properties of extruded compacts of crystal bar zirconium.

Abstract: "A small low impedance flux monitoring device has been built which utilizes the heating (and consequent chance in resistance) of a boron coated platinum wire. Feasibility tests in the Argonne-GP-3 reactor indicate that it may develop into a wide range instrument, particularly useful at high flux levels. Design and constructional details of the bolometer and its associated circuits are given. The circuitry is somewhat unique since it is in effect an all electronic self-balancing bridge. Future lines of research are suggested to solve some of the remaining problems."

Quarterly progress report discussing activities related to the Vallecitos Boiling Water Reactor (VBWR) and related facilities.

Quarterly progress report discussing activities related to the Vallecitos Boiling Water Reactor (VBWR) and related facilities

The object of the work performed under this contract was to investigate the possibility of gas plating copper base metal with (a) pure chromium metal from chromium hexacarbonyl vapor; (b) chromium-nickel plating from a mixture of chromium hexacarbonyl and nickel tetracarbonyl. The object of the work performed during the final month was to confirm the fact that the gas plating of chromium metal and chromium-nickel laminates free from nitrides, oxides and carbides was practical.

Abstract: "Refinement of grain size of the base uranium-chromium eutectic alloy (uranium-5 w/o chromium) by ternary additions is discussed. Thirteen additions to the base alloy were investigated, and three additions were found to exhibit worthwhile grain-refinement tendencies. The three alloys, uranium-5 w/o chromium-0.2 w.o molybdenum, uranium-5 w/o chromium-0.2 w/o germanium, and uranium-5 w/o chromium-0.2 w/o niobium, were heat treated to produce final grain-size structures of between 0.015 and 0.033 mm."

From introduction: "Preliminary design and analysis of the 300 MWe core."

"Test results indicated that graphite is not suitable for seal face material. A program to evaluate various materials and seal face geometries was initiated. A seal run using nucerite-bearium combination was carried on for six hours."