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.

Technical report describing the purification and separation by distillation of UO2F2 from D2O. In the experiment which is discussed 2,129.6 lbs of UO2F2 were dissolved in 6,605 lbs of D2O. The average isotopic purity of the D2O decreased during the distillation from 99.77% to 99.73%. The dissolved impurities were less than those present originally in the heavy water.

Technical report discussing that the deuterium concentration of heavy water can be determined by equilibrating the water with deuterium gas in the presence of a catalyst with subsequent analysis of the equilibrated gas on the mas spectrometer. The apparatus for equilibration analyses maybe be considered in three parts: 1) apparatus for introducing the ingredients into the reaction chambers; 2) the reaction chambers; 3) the mass spectrometer for analysis of the equilibrated gas. The isotopic composition of the deuterium gas to be used as the starting material is primarily governed by what gases are available. In general it is best to use gas within about one percent on either side of the final equilibrium composition. No reaction takes place between deuterium gas and water molecules in the absence of a catalyst. Platinum oxide is used as the catalyst.

Abstract. The precipitation of Pa233 with MnO2 from a solution of thorium nitrate has been studied in some detail and seems quite satisfactory up to 36 gm Th(HO3)4 4H2O per 100 cc solution. The concentration of Pa233 with respect to the manganese dioxide carrier and the thorium precipitated with the carrier appears to be accomplished quite well by either a series of MnO2 cycles or thorium iodate cycles. Volatility methods for both the separation of Pa233 from the original thorium and for its separation from MnO2 are now under investigation. It has been decided that thorium carbonate will the the thorium compound used in the pile at Site X.

Technical report listing the errata for pages 2, 4, 5, 6, 7, and 8 for report CC-918.

Technical report that information has bee obtained on the effect of beta and gamma radiation on the electrical resistance of insulating materials The results are summarized. The recovery to original resistance values has been measured. In general, the initial rate is rapid for the first few hours; the rate then decreases sharply. Certain samples show evidence of complete recovery. Effects on mechanical properties of several plastics has also been studied. Data on gas evolution from several organic materials including those suggested by the physiological shield have been extended to include both beta and deuteron bombardments. Samples of "Press-wood" are being evaluated. The effect of current on the H2O2 production in water containing I- has been studied at several I- concentrations. Water contain-dissolved CO2 shows the presence of oxidant (presumably H2O2). H2O2 has been produced by recoil protons from the scattering of fast neutrons in de-oxygenated water. Radioactive solutions do not greatly affect the applicability the glass electrode providing the electrode is thoroughly washed with distilled water before immersion in the standard buffer solution.

Abstract. Thorium peroxide was precipitated from thorium nitrate solutions containing varying amounts of sulfate ion and of hydrogen ion. The washed solids were analyzed both wet and dry. Analyses were made for thorium, peroxide oxygen, sulfate, nitrate, and water contents. X-ray powder photographs of the dried samples by W.H. Zachariasen showed the presence of only two phases. When precipitated from high sulfuric acid, the solid phase was isomorphous with Th(OO)SO4.3H20. More weakly acid solutions whose sulfate content was varied over wide limits [SO4--/Th(IV) (in solution before precipitation) = 0.005 to 67.0] yielded a solid, isomorphous with thorium peroxide nitrate and containing 3.0 to 3.8 peroxide oxygen atoms for each thorium atom. The sulfate content of this latter phase varied continuously between the limits SO4--/Th(IV) = 0.34 to 0.01 with nitrate ion present when the sulfate content was very low. This continuous variation in composition is in agreement with the previously proposed structure of this phase.

Technical Report: A generalized review of the chemical problems and researches related principally to the heavy water homogeneous pile is presented herewith. The report covers researches performed principally by the Columbia Group who initiated the study. This report contains a chronological outline of the development, a discussion of some special topics whose significance is paramount in any slurry pile discussion, and finally an outline of important research problems remaining, roughly graded in order of their importance. No attempt has been made to be either complete or detailed in the discussion. The emphasis has been principally on furnishing a broad guide to those who may t some future date take up this work.

Technical report with short reports on (1) P-9 recovery from UO2F2 solution; (2) Correlation of theories on action of radiation on matter; (3) Literature surveys on organic compounds and on chemistry of UO2F2; (4) effect of radiation on organic compounds; and (5) Effect of radiation on 100 area construction materials.

Technical report containing short reports on (1) Mass spectrometer studies; (2) Purification of heavy water; and (3) Equilibration studies.

Technical report with short reports on (1) Heavy water analysis and standardization, and Specific gravity of pure D2O; (2) Homogenous exponential experiment; (3) Recombination of pile gases; (4) Slurry pumping studies; and (5) Electron microscope laboratory.

Technical report. Photomicrographs showing the effect of heating polished uranium surface at 600, 700, 850, and 1000 degrees C, and sandblasted and cut surface at 1000 degrees C are included.

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.

Abstract. a method of recovering thorium from slag from the bomb process of producing thorium has been developed. HCl and NaOH are the only chemicals required in quantity. Materials required for a representative slag are given.

Abstract. The distribution coefficient of U(VI) between perchloric acid solutions and benzene solutions of TTA has been measured as a function of the acidity. It was possible to interpret the data in terms of the charge on the U(VI) species present in the aqueous phase. The experiments indicate that U(VI) exists as an ion charge +2 at acidities from 0.1M to 2.5M. In the interpretations of the distribution data, it was necessary to know the acidity coefficient of the uranyl chelate in the benzene solution. This was determined by measurement of the solubility of the compound UO2K2 - xH2). The activity coefficient of UO2K2 was found to decrease rapidly as the concentration of TTA in the benzene phase increased above 0.1M. This is probably due to the formation of a species involving more than two TTA molecules per U(VI)

Technical report. Quite pure anhydrous ThCl4 in small quantity (8-10 g charge) has been prepared by the action of a mixture of Cl2 and CCl4 vapor on ThO2 at 675 degrees to 725 degrees C.

Technical report on the studies that have been made on the composition and thermal decomposition of uranyl peroxide. The conditions of precipitation and drying have been found to have no appreciable effect on the composition of the compound, but do affect the physical appearance of the precipitate and the rate of thermal decomposition. The UO4 + 2H2O appears to be thermodynamically unstable with respect to UO3 at 25 degrees C and atmospheric pressure, although the rate of conversion is extremely slow. The UO4 + 2H2O is completely converted to UO3 on standing at 150 degrees C and atmospheric pressure for two weeks. Partially decomposed uranyl peroxide samples contain extra oxygen which is released on immersing the sample in water.

Technical report abstract. A rapid procedure for the preparation of very pure carrier-free Zr and Nb tracer involves the chloroform extraction of the cupferrides of Zr and Nb activities from process solutions. Zr and Nb form very stable chloroform soluble cupferrides in acid solutions (CK-993) and are separated from other fission elements almost quantitatively to yield pure mixture of Zr and Nb activity. A minimum of operations is required and the method is easily adaptable to remote control.

Abstract. In addition to the hexagonal and monoclinic bismuth phosphate precipitates, whose structures are now known, a third crystalline phase has been found to appear in BiPO4 precipitates after (a) extremely long digestion in concentrated nitric acid; (b) oven drying at 800 degrees to 1000 degrees. Thought very small single crystals of the component have been isolated, nor crushed sample contained less than 30% of the beta-form. The cell size and symmetry of the crystal indicates that there ae two bismuth atoms in the cell, and there is no evidence that the compound is not BiPO4. It is suggested that this maty be a third form of BiPO4, stable over a short range of conditions, and tending to revert to the beta-form.

Technical report: The apparatus for the low pressure combustion method of determining carbon in iron and steel has be redesigned to increase the speed of manipulation. It has been tested by running several thousand determinations and found to yield results in good agreement with Wooten's form of the apparatus. A detailed description of the equipment and its manipulation is given together with an account of experimental studies on the method. Results are also shown for the carbon content of copper.

Technical report. Three extractions of a diethyl ether solution of uranyl nitrate with small portions of water are effective in removing rare earths, as is shown by radio-gadolinium and radio-europium tracer experiments. A study of representative ethers, alcohols, ketones, and esters showed that diethyl ether and a mixture of 85% ethyl methyl ketone with 15% xylene are the best solvents for the extraction.

Abstract. It has been established that heating samples of graphite during exposure in a pile decreases substantially the observed changes in the elastic modulus and electrical resistance caused by the irradiation. The functional relationship between the percentage changes observed and the temperature of exposure resembles the relationship between the final percentage changes and the temperature of heat treatment after exposure (cf. report CC-1668). Anomalous results reported previously for higher temperatures in CC01669 are now shown to be attributable to a destructive influence on the graphite, probably oxidation of samples exposed in air.

Technical report. The effect of temperature during pile exposure on the fast-neutron-induced change in properties of graphite was studied. Temperatures up to 125 degrees C have no effect upon the rate of increase of elastic modulus; pieces exposed at 300 degrees C on the other hand show no change at all in elastic modulus. The increase in electrical resistance s an inverse function of the temperature of exposure at all temperatures in the range 60 to 300 degrees C.

Abstract. The physico-chemical methods of determining nitric acid and thorium nitrate in solutions containing these two materials were investigated. Conductimetric titration with sodium hydroxide can be used to determine nitric acid accurately. the titration of thorium nitrate requires a separate standardization of the base however, since a basic salt is precipitated rather the normal hydroxide. The titration of thorium is reproductible however, so and empirical standardization can be used. The measurement of the specific gravity and refractivity of the solutions provides a method of determining the concentrations in terms of these two variable. Equations for the concentrations in terms of specific gravity and refractively are given, both in pure solutions and in those saturated with methyl isobutyl ketone.