Thorium bismuthide when crystallized from a solution i bismuth results in large platelets which may be as large a 1 centimeter in diameter. A slurry of these platelets is difficult to pump through pipe lines and filters. The particle size can be reduced by (1) very rapid cooing (approximately 1000 degree C per second) or (2) ultrasonic treatment. The latter, much easier to attain in large scale, gives equiaxed particles of thorium bismuthide.

An investigation was made of the neutron and gamma flux distribution along the entire length of a withdrawn control rod in the SRE in order to determine heating, activation and dose rates produced by the streaming neutrons and gammas.

Various methods and procedures for preparing uranium dioxide bodies for metallographic examination and study have been utilized by various investigators. Unfortunately, these methods are not in general satisfactory for use on irradiated uranium dioxide. Since radiation damage studies on irradiated uranium dioxide require use of electron microscopy, and reveal structure by virtue of surface relief. This report covers an investigation of etching methods compatible with radiometallurgy and electron microscopy requirements.

A study of the nuclear safety in the storage and transportation of PRTR fuel elements has been made. This study was based on 7-rod clusters of plutonium-aluminum allow fuel elements containing 1.8 per cent Pu by weight. Each cluster is 7 feet 4 inches in length and contains 270 grams plutonium. Drawings of the "New Fuel Storage Pit" (H-3-11030) have been reviewed for nuclear safety. Nuclear safety criteria for the design of a lead shielded fuel transfer cask as well as criteria for the storage of these fuel elements outside the facilities mentioned in the above drawings have also been reviewed. For water moderated systems, a homogeneous model of plutonium, aluminum, and water was used t evaluate the critical parameters. These results should be conservative. At the conclusion of an experimental program to determine criticality parameters of PU-Al alloys in light water, a theoretical approach will be developed to calculate such criticality parameters.

Water treatment systems for preparing and maintaining high purity water in out-of-reactor or in-reactor test oops are becoming increasingly important. In out0of-reactor experiments the presence of ionic impurities in the water has a marked influence on film formation and corrosion rates. It is therefore , imperative that these impurities be maintained at the lower practical concentration.

Fused uranium dioxide has desirable characteristics for fabricating high density nuclear fuel elements by swaging. Methods of preparing dense uranium dioxide particles being investigated at HAPO include are arc fusion, and sintering and crushing of low density powder. This paper reports the results of exploratory experiments to prepare fused uranium dioxide by induction heating of low density powder in graphite crucibles.

Recently proposals for justifiable additions to the Plutonium Recycle Test Reactor Complex were presented to the Atomic Energy Commission at their request. In addition to a critical reactivity measuring facility in the fuel element storage basin, the following in-reactor loops were proposed: 1. A high pressure, H2O cooled fuel test loop. 2. A rupture loop to investigate fuel element failures. 3. One or more materials testing loops.

Data has been previously presented to show that aluminum corrosion in high temperature water may proceed with either a parabolic or a linear dependence on time. The rate of the parabolic process is an Arrhenius function of temperature and essentially independent of alloy composition. More recently several aluminum melts have been tested which corrode by a logarithmic rate process.

Ceramic insulated, stainless steel sheathed thermocouples have been used to monitor temperatures of encapsulated uranium specimens, both in-reactor and out-of-reactor. No operational difficulties are encountered at low temperatures, but at a temperature of 700 C or greater, a eutectic is formed between uranium and iron. This reaction destroys protective sheath and results in thermocouple failure. A typical example of the phenomenon has been reported by J.W. Geffard of the Fuels Development Operation. Hanford Laboratories. Tantalum was suggested as a barrier between these metals and an evaluation of this system was made at 500 C.

Plutonium Oxide Fuels. Mixtures of PWR grade UO2 containing 10, 20, 30, 40, 50, and 60 w/o PuO2 were sintered in hydrogen for 44 hours at 1600 C to get additional data on solubility in this system. Densities of all the pieces were low, approximately 80 percent of theoretical; however, solid solution formation was complete in every case. The low density material should not affect lattice parameter values, but it did slightly reduce the intensity of the reflections.

This report was written to describe the instrument and test results obtained. It is understandably imperative that such alarming devices be incorporated in various areas of the plant to provide an alarm or warning for increasing dose rate from gauss radiation fields.

Photographic observations of the behavior of uranium dioxide at high temperatures are of great value in designing and evaluating fuel elements. This paper reports the growth of uranium dioxide crystals by vapor deposition during out-of-reactor and in-reactor experiments.

The purpose of this report is to show the impedance of an approximate equivalent circuit on a complex plan for various constant frequencies and different metals. The equivalent circuit represents a testing coil driven with an AC voltage and a network to represent the impedance of the metal.

Uranium dioxide, uranium monocarbide, and uranium mononitride are potentially useful ceramic nuclear fuel materials. This paper reports the results of a determination of the melting points of these materials.

Organic compounds have been considered for use as reactor coolants for two primary reasons. First, the high boiling points of the compounds would permit the reactor to operate at high temperature without the need for the high pressure required when water is used as a coolant. Secondly, the compounds are less corrosive than water and would permit the use of carbon steel rather than stainless steel components in the reactor. Unfortunately, the organic compounds proposed for use as reactor coolants have a greater tendency to leak than water and are thus more difficult to seal. A development program was established to evaluate the types of closures required to produce a leak-tight system. This report presents the results of the evaluation. Two proposed coolant compounds, monoisopropylbiphenyl (MIPB) and the eutectic mixture of 55 per cent ortho terphenyl, 25 per cent biphenyl, and 20 per cent meta terphenyl were used.

The following is an attempt to explain the method by which the precision associated with an observed volume reading in a process vessel (E-12, C-1) should be calculated based upon a regression analysis of cumulative data. There are two types of volume measurement consists of estimating the total volume in a vessel at some inventory time. A transfer measurement consists of estimating the volume between two levels within a tank.

Primary control of the PRTR is achieved by regulating the level of the heavy water moderator which is held in the reactor vessel by a helium gas balance system. Emergency shutdown is effected by a gas-balanced moderator dump system which drain the moderator from the calandria at a rapid rate. This report presents a quantitative appraisal of the reactivity effects due to moderator level changes in controlling or scramming the reactor. In conjunction with the reactivity calculations, solutions were obtained which yield an evaluation of vertical flux or power distributions for any positioning of the moderator level. Coupled with the radial distributions for a given fuel loading, this information is useful in obtaining the value of the maximum specific power associated with a given power of operation and moderator height. The calculations were made using VALPROD, a one dimensional, multigroup diffusion theory reactor code programmed for the IBM-650 computer.

The last fifteen years have seen the discovery of ten transuranic elements. This paper (presented at the Mendeleev Chemistry Conference in Moscow) deals only with the transplutonium elements, i.e., those elements with atomic number greater than 94. This will be a detailed discussion of the techniques that have been devised for producing and identifying elements 101 and 102 and the possible applications of these methods to elements beyond. There will also be a brief review of the discovery of all the transplutonium elements to show the gradual change in experimental methods from the early days.

It is the purpose of this paper (from a talk given at Mendeleev Chemistry Conference in Moscow) to give a brief progress report on work which is being done on very heavy elements at the Lawrence Radiation Laboratory in Berkeley. The subject matter is divided into three broad classifications. The first classification includes production of the isotopes, the second deals with investigations of their chemical properties and the third includes studies of the nuclear properties.

A group at the Berkeley Bevatron constructed a rapid beam ejector to produce the brief pulses of particles required for optimum bubble chamber photographs. Energy stored in a capacitor bank is transferred to an air-core magnet surrounding the proton beam of the Bevatron. The protons are displaced from their normal orbit and strike a suitably located target; particles from this target can then emerge from the Bevatron. A capacitor bank of 120 pf stores 13,500 joules at 15,000 volts. Two ignitrons in parallel connect the capacitor to the magnet. The magnet current rises to 52,000 amperes in 55 microseconds; at peak current a register is connected in parallel to damp the current decay.

A report regarding geological survey investigations in the U12b.03 and U12b.04 Tunnels, located at a Nevada test site.

Abstract : Methods for the chemical separation of strontium, barium, cesium, cerium, yttrium, zirconium, niobium, and tungsten from complex matrices are described. Procedures for the radiometric determination of the longer-lived isotopes of these elements are outlined. Inert carriers are added and the sample is dissolved by fusion with sodium carbonate. The melt is leached first with water and then with hydrochloric acid. The elements are recovered from these fractions by a series of wet chemical and ion exchange procedures, and gravimetric and radiometric determinations performed.

Abstract: Both direct and coincidence counting apparatus are described. The elimination of cosmic ray events by coincidence plus gamma ray shielding permits the reduction of counting rates far beyond that obtainable with shielding alone. By selection of materials and development of new components and techniques, the residual background count of beta counting equipment can be reduced to a very low value. Geiger counter equipment for routine laboratory measurements is described, have a background count of 0.7 c/m. Scintillation counters are shown to have a background of 0.2 c/m at 30% efficiency. A portable Geiger counter with a 3.7 c/m background is also described.

Abstract: The primary coolant of the SM-1 (APPR-1) was analyzed for short-lived and fission product activities. Manganese-56 was found to be the predominant non-fission product nuclide contributing to the short lived activity. Fission products were found in the coolant. It is concluded these fission products originate from a defects in the cladding and from surface contamination of the fuel elements.