Report issued by the Bureau of Mines over experiments conducted on fuel-gas mixtures. The results of these experiments are presented. This report includes tables, graphs, illustrations, and photographs.

This report studies ammonium dichromate and the conditions it needs to be under in order to precipitate and be isolated from an aqueous system.

The following report focuses on research made to determine whether the service performance of UO₂ fuel-elements cores for the PWR can be improved by certain ceramic or metal additions.

From introduction: This bibliography is an annotated list of selected reports that were publicly available as of May 31, 1956, pertaining to the uranium content and/or radioactivity of igneous and metamorphic rocks and minerals in the United States.

Thesis describing a research conducted to extend observations on nuclear energy levels and how they effect the nucleus itself, and an investigation on the gamma rays associated for the even-even isotopes and to obtain additional data for the oddmass neclei in the hope that more regularities will become apparent for that class of nuclides.

The following report discusses the data of the Z-field pick-up loop, an effective diagnostic tool introduced to help experiments with the linear pinch.

Introduction: A reconnaissance of the Black Brush property was made by geologists of the Atomic Energy Commission in March, 1955. This anomalous area was located by an earlier airborne radiometric survey. the examination consisted of preliminary sampling and surface and underground radiometric traversing.

A report about uranium content of water from various rocks in certain states in the United States. It attempts to locate areas in which large amounts of uranium in the water will reflect the presence of nearby uranium accumulations.

A report regarding the uranium content of ground and surface waters in Western Kansas, eastern Colorado, and the Oklahoma panhandle. This report concerns work done on behalf of the Division of Raw Materials of the U.S. Atomic Energy Commission.

A report discussing an airborne radiometric survey of the Lone Pine, California project.

A preliminary report has shown the potential importance of organic reactor coolants to Hanford technology. The salient points are complete avoidance of corrosion problems and accomplishment of DPR performance with low pressure technique. The recommendation of the report that loop tests be made at Hanford is to be acted upon by Recirculation Technology Unit as soon as organic coolant material is received. To insure starting this experimental work fully abreast of the information available, a trip to sites working with organic coolants was made. Specifically, data were sought on practical details of design for handling organic coolants, heat transfer and fouling characteristics, corrosion of materials, and hazards of handling organics.

Contemplated higher tube power for future reactor operation will probably require a fuel element jacketing material more corrosion resistant than presently available aluminum alloys. Zirconium and its alloys are generally regarded as the most promising jacketing candidates for high temperature operation, particularly for exposures of long duration. In order to obtain assembly, welding, and corrosion data, twenty Al-Si bonded and twenty unbonded Zircaloy fuel elements were prepared for KER loop testing. This report describes the technique developed to weld Zircaloy jacketed fuel elements and presents the results of end closure corrosion testing and metallographic examination.

The dependence of the resonance integral for thorium upon geometry and thorium temperature has been determined through reactivity coefficient measurements performed in the Hanford Test Pile. The geometry dependence was investigated using thorium cylinders of various diameters in the form of solid elements and shells. The temperature dependence (Doppler broadening) was studied by heating thorium elements and permitting them to cool while observing the change in pile reactivity.

Neutron attenuation in the old pile shields is dependent more and more on the slowing down characteristics of the iron as the hydrogen is baked out of the masonite. For neutrons above 1 or 2 Mev, iron does a good job by inelastic scattering. However, below this energy attenuation can be done only by the gradual moderation by elastic scattering to thermal energies with subsequent capture in the iron. Since iron is heavy and thus a poor moderator, there is a good possibility that many neutrons of intermediate energy will leak out of a burned out shield. Also, iron has a large dip in its cross section at 25 Kev which might allow a large burst of neutrons at this energy to leak out. Measurements using a lucite moderator with gold foil detectors indicate a large leakage of neutrons of intermediate energy, but interpretation of these measurements is difficult. These considerations prompted an attempt to get a rough idea of the energy distribution of the leakage neutrons through pure iron using a simple qualitative theory.

Description of Invention: Chloride-induced corrosion is a serious problem in the Purex acid recovery operation and in the evaporative concentration of process streams and waste solutions. In the case of Purex acid recovery, it has been shown that trace chloride will volatilize with the nitric acid and reflux in the acid fractionator, thus causing especially severe corrosion at that point. These traces of chloride may enter the process form several sources, i.e., as an impurity in the technical grade chemicals used in making up the various aqueous process streams, by hydrolysis or radiation decomposition of carbon tetrachloride (a promising diluent for tributyl phosphate), or by incomplete removal of the hydrochloric acid employed in some flowsheets for effecting the dissolution of certain difficulty soluble nuclear reactor fuel elements.

In connection with studies of the chemical reactivity of PuO_2 to hydrofluorination, samples were examined by X-ray diffraction for crystallite size and perfection. The PuO_2 was formed by thermal decomposition of the oralate. The reactivity of this oxide, as well as that of other solid oxides is affected by the conditions of preparation. Besides the obvious influence of surface, including lattice strain and other structural irregularities in the particles. Each particle is composed of a number of crystallites. The extent of crystallites size and perfection will be indicated by the width of a diffracted X-ray beam. Since separation of these two caus4es would require a detailed analysis, the observed broadening was interpreted on the assumption of crystallite size effects alone. However, the variable factor in preparation method was temperature, and it is to be expected that crystallite growth with annealing will occur in part at the expense of energy stored in nonequilibrium states of the crystal, i.e., imperfections. The objectives of this study were to establish a convenient method for determination of PuO_2 crystallite size and to obtain estimates of the crystallite sizes of seven given samples.

A report about the mechanical properties of dilute uranium alloys which might be crucial to developing high strength alloys for possible use as fuel.

Progress report of the Oak Ridge National Laboratory Analytical Chemistry Division providing updates on various projects, experiments, and other work in ionic analyses, analytical instrumentation, radiochemical analyses, activation analyses, spectrochemical analyses, inorganic preparations, optical and electron microscopy.

The so-called Fluoride Volatility Processes refer to several proposed non-aqueous methods of processing irradiated fuel elements. In each of these methods, the uranium is fluorinated to uranium hexafluoride and then decontaminated by distillation. One of the methods, involving direct fluorination of the uranium by bromine trifluoride, has been under investigation at BNL since 1950; subsequently a pilot plant was built to study this step of the process. The objectives of the program were to investigate the technical feasibility of continuous dissolution, and to determine the effect of process variables on the capacity of the equipment; namely the effect of temperature, solution composition, flow rate, and uranium history on dissolving time as related to fuel elements of the types used at BNL, ORNL, and Hanford. The nominal capacity of the dissolver was five pounds of uranium per hour and all process equipment was fabricated of Monel. Special equipment components and numerous safety features were utilized. The major equipment development was a canned-rotor pump used for circulation of the dissolver stream through the heat exchanger. A system for continually charging slugs to the pressurized dissolver was also developed. Operation consisted of batch runs which were made with unirradiated BNL slugs in order …

Physical calculations have been performed for various combinations of the four types of fuel assemblies to be used in the EBWR core. Two thicknesses of plates (0.205 in. and 0.274 in., including two 0.020-in. cladding layers) are to be made of both natural uranium and uranium containing 1.44% U235. Any given fuel assembly contains six identical plates. A total of 148 assemblies, 74 natural and 74 enriched, are to be fabricated. Various configurations of these fuel assemblies can be used to (1) change the critical size of the core, (2) change the power distribution in the core or (3) change the amount of reactivity corresponding to a given steam volume in the core. Physics calculations show that any uncertainties in the required critical mass are adequately covered by the number and variety of fuel assemblies, and that the changes in core characteristics possible with the different fuel assemblies should provide valuable information about the factors affecting maximum power density and stability in a boiling reactor.

It is assumed that when a hole appears in the cladding of a reactor fuel tube the fission products in the space between the fuel and the cladding will diffuse towards the hole. There they are swept away by the flow of steam past the hole. The process of diffusion is assumed to be governed by the ordinary diffusion equation with the boundary condition that the density of the fission products is zero at the surface of the hole. The diffusion equation is solved for the case of steady-state emission for a number of geometrical arrangements: long slit in plane surface; long slit in cylindrical surfaces circular hole in plane surface; circular hole in cylindrical surface; hole at end of cylindrical fuel rods and diffusion space of variable thickness. The time dependent solution of the diffusion equation is also found for a planar diffusion space. The effect of a temperature gradient is discussed.