Abstract. A review of all work on uranium hydride published in the CC, CT, CN and CE reports to January 1, 1944, is presented. Some additional information not yet published has been included, so this report includes all data known from the above sources and at Ames to the above date. This report supersedes all previous report on uranium hydride coming out of the Ames laboratory.

Technical report describing a gasometrical method for the determination of H2 in extruded U rods.

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. Areas covered are properties of uranium halides, properties of uranium nitrides, and hydride formation at high pressure.

Technical report describing the investigation of the short-lived activities produced in oxygen compounds by irradiation with pile neutrons. The most prominent of these activities in cooling water is a beta and gamma emitting activity of about 8 second half-life. Because of its production by epicadmium neutrons it was believed to be the 8 second N16 produced in the pile by n,p on O16. The identification has been accomplished and it is established that the 8 second activity is N16. Part 2 of the report deals with the determination of the recoil range of the Al28 atoms formed by pile n,p reaction on Al27.

Technical report. Long-time tests have been made on the effect of various types of radiation on the corrosion of 2S aluminum in simulated W water. In no case was any acceleration of corrosion by the radiation observed; the effect of radiation, if any, appeared to be a protective one. Deuteron irradiation did accelerate the corrosion of mild steel at low flow rates in hot water of pH 6 to 7, but no appreciable effect was observed with copper, stainless steel, or tuballoy. The general theory of the effect of radiation on corrosion is discussed, with the conclusion that no acceleration of corrosion by radiation is to be expected in most cases of practical interest.

Technical report. The extent of the Wigner effect in graphite at any point in a pile is sensitive to the local structural situation. It is greater near a slug. These control experiments give information on changes in graphite to be expected in selected places in the pile.

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

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: Experiments on colloid milling and pumping show that uranium trioxide, when carefully dehydrated, can be dispersed in water to form a relatively stable slurry, suitable for a homogeneous slurry pile. At temperatures considerably below those of anticipated pile operation particle size growth occurs attended by increase in settling rate and decrease in viscosity. Theses properties of the slurries may be strongly affected by impurities present as well as by special operating conditions.

Abstract. the electrodeposition of uranium metal, in the form of tree-like deposits, from molten strontium halide baths is described. Under the best conditions studied, approximately 40% recovery is attained. Freedom from side-reactions of the reduced uranium with anode products and/or refractory materials, and high cathode current densities appear to be essential to the success of the process. the refining of uranium under similar conditions appears to occur quite readily, with approximately 50% current efficiency. The preparation of UI3 is also described.

Abstract. Wigner effects on aluminum, beryllium, and tuballoy have been studied by the electrical resistance method. Samples were exposed during an interval which would have produced an increase of approximately 22% in resistance of AGOT-K graphite. The resistance of tuballoy increased approximately 1%. It is shown that the increase can be accounted for by the amount of fission product impurity formed during the exposure. Neither aluminum nor beryllium showed any change. In the case of Be, the Wigner effect may be obscured, to some extent, by the approximately .2 - .3 atom % of impurity present in the samples. Based on the increase occurring in ADOT-K graphite, a change of approximately .2 - .5 x10-6 ohm-om might be expected in the case of Be. The accuracy of the method was sufficiently great to detect a change of this magnitude. Other experiments with Be will be undertaken when purer samples are available. Meanwhile, some samples of the present type ae being subjected to further irradiation.

Abstract. A portion of the liquid-solid phase equilibrium region of the system U-UBr3 has been investigated by the method of thermal analysis. Uranium tribromide was prepared by introducing bromine vapor into a bulb containing finely divided uranium formed from the hydride. Cooling curves were obtained with tribromide and then with various compositions of tribromide and uranium. the information obtained showed that no solid sub halide exists but that the metal was soluble in the halide.

The following report describes and foretells the situation in medium in which neutrons are being (a)produced as fast neutrons, (b) slowed down to thermal speeds by impacts with nuclei, and (c) absorbed by nuclei in such a manner that sometimes fresh fast neutrons appear at the place where a thermal neutron has just appeared.

A report which investigated vacuum distilation, entrainer gas distillation, and entrainer gas plus bromine vapor distillation.

The following report describes tests made for the purpose of determining the accuracy and permanency of various types of high resistance bleeders, and their resistance variation during use over a period of approximately six months.

Abstract: "Photographic plates have been used to measure the energy of neutrons from the fission of 25. The spectrum as inferred from the ranges of 850 protons recoiling in the forward direction shows a very wide maximum at ~1.5 Mev with an exponentially decreasing high energy tail which extends beyond 7 Mev. The minimum energy neutrons recorded were ~700 kv. If the spectrum is extrapolated to zero, one finds that this average neutron energy is about 1.85 Mev. The stopping power of the plates was calibrated by the use of monochromatic neutrons from the Li-7(pn) Be-7 reaction and the d-d reaction."

The following report describes a modified Kraus type reactor that had been constructed for use in bets chemical conversion operations.

Technical report covering (1) analysis of uranium bromide and chloride samples, (2) the ferric-nitrate method of analyzing uranium fluorides for fluorine, (3) spectrographic determination of boron, cadmium and manganese in magnesium metal, (4) service analyses. contributions to other problems, (5) attempted preparation of uranous oxyfluoride, and (6) corrections in previous reports.

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 summarizing our knowledge of the chemical effects of ionizing radiation upon water and upon aqueous solutions of inorganic compounds. The types of radiation considered are beta rays, gamma and X rays, and heavy particles, notably neutrons, deuterons, alpha rays and fission recoils.

Technical report abstract: Since UNH is a highly dissociated compound which ionizes to NO3 and (UO2), the latter ion being very weakly basic, a solution of pure UNH is quite acid (pH about 3). It is possible to titrate to a phenolphthalein and point with standard caustic solution and obtain a figure which represents the free acid plus the NO3 from the the UNH. However, titration of the free nitric acid alone in such a solution presents quite a problem. By precipitating and removing uranium from solution by means of potassium ferrocyanide, the residual free acid may be titrated directly by means of standard caustic using either methyl red or phenolphthalein indicators, with an error of less than 4%. A method is given to determine formic acid, should that acid be present in the mixture.

Technical report. The object of the research is to determine the procedure and equipment for the preparation of U233 on a semi-works scale. The general proposed procedure is that thorium carbonate in aluminum cans will be irradiated with pile neutrons. The Pa233 resulting from neutron absorption the Th232 and the decay of Th233 will be extraction from 99% of the thorium and the natural U in thorium by MnO2 precipitations. The Pa233 will then be allowed to decay to U233 which in turn will be isolated from the remaining Th and partially decayed Pa233 by ether extraction.

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.