Abstract. Samples of pile graphite, irradiated in a test-hole at Hanford for 15 months, have been assayed for radioactive C14, yielding 0.38 ± 0.04 microcuries per gram. At this level of activity, the pile graphite contains very valuable amounts of C14. The relation between the above assay and the probable average assay of pile graphite is discussed, and it is concluded that the latter is almost certainly above 0.3 uc/ gram. Controlled oxidation of this graphite, either with oxygen at ~ 750°C, or with chromic acid "cleaning solution" at room temperature, yields early fractions which are highly enriched in C14. Concentrations of 5-fold with oxygen, and 50-fold with CRO{sub3}, have been observed. The relation between the observed enrichment and the Wigner effect is discussed, and a mechanism accounting for the observations put forward. According to this, about 25% of the stable carbon atoms in the lattice have been displaced by Wigner effect, a large fraction of which have healed the migrating to crystal edges. All the C14 atoms have been displaced, and the same fraction of these migrate to the edges. The enrichment then results from surface oxidation, in the oxygen case. Predictions are made on the basis of this …

Technical report that attempts to bring together the various chemical procedures which proved most useful in studying the results of cyclotron bombardment or small scale neutron bombardments of heavy element targets. The report is limited to the elements of the "actinide", or second rare earth series, starting with thorium and including the newly discovered elements of atomic number 95 and 96. Every attempt is made to include all details necessary so this report can serve as a practical laboratory guide. The report covers separation problems, time factors, and dealing with dangerously radioactive targets.

Technical report describing the attempt to separate the long lived fission product oxides by volatilization methods. A fractionization crucible was used. The fractionations give a fair idea of the relative volatilities of the longer lived fission products and also of the degrees of separation of the plutonium oxide or oxides from the fission products.

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)

Abstract. A satisfactory method has been found for dissolving thorium metal and thorium oxide in heat-treated 25-12 stainless steel vessels without excessive corrosion of the vessels. The dissolution medium consists of strong HNO3 containing a small amount of fluoride or fluo-silicate. the fluoride required has no harmful effects on a subsequent solvent-extraction step for a separation of uranium isotopes from the dissolved thorium.

Abstract. A method for the preparation of beryllium oxide of high purity is presented. Beryllium basic acetate (BeO-3Be(C2H3O2)2) is prepared from the metal or a convenient salt, a chloroform solution of this material extracted with redistilled water, the dried basic acetate distilled in a quartz apparatus, and this purified material converted to the oxide by fuming down with sulfuric acid and igniting at 1000 degrees C. Impurities detectable spectrographically were reduced to a very low level.

Technical report: Measurements have been made on the equilibrium between Cu, Cu2+, U4+, and UO22+ in H2SO4 in an attempt to establish the value of the U4+ - UO22+ couple potential. The value of the formal potential for the U3+ - U4+ couple in 1N HCl at 0 degrees C was determined to be + 0.65 v.

Technical report. Numerous application of various column adsorption techniques to inorganic analytical chemistry have appear in the literature. The comparatively recent introduction of ion exchange resins has resulted in the development of efficient, simple, and rapid column adsorption methods. the principal service of column adsorption methods to analytical chemistry is that of providing a relatively simple means of separating an element in a sufficiently pure state so that a direct precipitation, ignition, and weighting, for example, will suffice to complete the quantitative analysis. Systems involving uranyl nitrate will naturally be emphasized in this report but information will be included concerning the separation of the individual members of a series from one another, such as in the alkaline earths and the rare earths.

Abstract. Methods of analysis for thorium, calcium, and nitric acid in solutions from thorium extraction purification columns are described and the results and errors are outlined. A brief description of methods of analysis that were not successful is included.

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.

Technical report describing that the use of controlled amounts of carbonate, acting both as complexing agent buffer led to a fairly satisfactory procedure for the determination of Th in Th-U alloys, using cupferron. The alloy, dissolved in NHO2, in the presence of HF, is treated with H2SO4 and the mixture is evaporated in SO2 fumes. The solution is diluted and (NH4)2CO2 is added. Th is precipitated from this solution with cupferron. The precipitate is weighed as ThO2 after ignition. An accuracy of 6% was obtained. A method was developed specifically for the determination of Th in U-Th alloys containing 1 to 10% Th. An ion exchange resin in column is used to separate Th from U, with NH2OH-HCl as complexing agent. The Th is then precipitated, ignited, and weighed in the conventional manner.

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.

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.

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.

Introduction. It has been known for a long time that thorium is precipitated by oxalic acid in acid solutions, but a survey of the literature showed no study of the limits of the acidity and oxalic acid excess which yield quantitative results. V. I. Spitzin reports on the solubility of thorium oxalate in varying concentrations of several acids, but the effect of an excess oxalic acid is not included. Since solutions are sometimes presented for analysis that contain more than the recommended two per cent mineral acid, it would be advantageous to be able to quantitatively remove the thorium without otherwise altering the solutions. This was especially of interest in solutions containing bismuth, since it was hoped that some amounts of thorium could be precipitated in nitric acid solutions containing large quantities of bismuth. In removing the bismuth, first by a bismuth oxychloride precipitation, thee is every opportunity for carrying of the thorium.

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.

Introduction. the colorimetric determination of iron based on the formation of the colored ferrous-1,10-phenanthroline complex has been used successfully by a number of investigators. In this technical report, its adaptation to the routine determination of iron in cerium, thorium, and beryllium metals and their compounds is described.

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 two experiments performed to compare the amounts of fission gases swept out of UNH solution with those amounts swept out of PU solution under idential condiditons. The charge wire technique was used. The essential date and the results are given in tables in the report.

Introduction. Some forty different uranium compounds have now been given diffraction study at Ames. Reports of these investigations are scattered in the Project literature; many have been reported in a sentence or two as a note along with chemical or metallographic reports. To make the results of this crystal structure work more available this summary of the Ames work has been compiled. (A similar summary has already been published from the Chicago laboratory.)

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.

Abstract. Fluorides and other halides are hydrolyzed completely by passing a rapid stream of superheated steam over the sample near 1000 degrees C in a specially designed platinum reaction tube. The steam and hydrogen halide are condensed by cooling, and the resulting distillate titrated with standard sodium hydroxide solution. The fluorides and chlorides of the light metals, hitherto thought of as very difficult to hydrolyze, are mixed with U3O8, or other metallic oxides, which reacts with the products of hydrolysis, thus shifting the equilibrium so that the reaction is complete in a comparatively short time. A description of the apparatus, including photographs, the recommended method of procedure, hydrolysis rate graphs, and suggestions for further applications of the method are given.

This technical report summarizes the work done in attempting to determine the solubility of helium in tuballoy. In general, the method used has been to allow the tuballoy to stand in contact with helium at one atmosphere presume at a fixed temperature for an extended period, then to pump off the excess helium to a low pressure in as short a time as possible (10-6 mm of Hg or less). The system was then closed off and the pressure increase was measured by a suitable gauge as a function of time. The metal was employed in the form of a powder in early measurements, and later as massive metal. The experimental techniques are described in the report.

Abstract. Spectrographic procedures for determining small amounts of the common contaminants in beryllium and its compounds are described. Suggestions relative to the preparation of synthetic standards are also given.