Abstract: "Aluminum electroplating was studied in a search for new methods of cladding uranium fuel elements. Uranium electroclad with 12 mils of aluminum over a 0.5-mil (or nickel plus copper) electroplate resisted corrosion for more than 100 hr in boiling water. This quality of protection was effected by hot pressing the electroclad uranium with 5.1 tons per sq in. for 5 min at 950 F. The electroclad uranium with hot-pressed samples paralleled those of later experiments with hot-pressed wrought aluminum claddings on uranium. In both cases, the uranium was electroplated with thin (0.5 mil) layers of metals to prevent aluminum-uranium diffusion, to aid bonding, and to assist in corrosion protection. This aluminum electroplating study helped to define the importance of the intermediate coating between the aluminum and the uranium, the effect of good bonds between the various layers, and the effects of hot pressing in protecting uranium with an aluminum cladding."

Abstract: "The purpose of this investigation is to determine the extent to which zirconium and zirconium alloys exhibit delayed failure (static fatigue) as caused by a combination of absorbed hydrogen and applied stress. Both notched and unnotched specimens of unalloyed zirconium and Zircaloy-2 have been hydrogenated to 200 ppm by means of a modified Sieverts apparatus; specimens were evaluated at room temperature. Thus far, no time-dependent fracture has been observed which can be attributed to the delayed failure phenomenon; it appears that these materials are relatively insensitive to static fatigue. The effects of grain size, temperature, cold deformation, and superheated water and steam corrosion on susceptibility to delayed failure are being determined."

Introduction: "In the evaluation of pile designs it is necessary to know how the production varies with the number of tubes. It has been possible to solve the problem in terms of some general parameters whose values may be quickly computed for any specific design when the pertinent information is available."

Abstract: "In a circulating-fuel reactor, the circulation of the fuel cause a damping of power oscillations of the reactor. This is demonstrated under the assumption, that there is no mechanical vibration coupled with the oscillation of reactor power, and that the shapes of the hydrodynamic flow does not vary with time."

Measurements of k∞, f, p, and ∈ have been performed in the PCTR in support of the EGCR Program. The values listed below were obtained for the 21.875-inch cell used in the PCTR measurements. They are for a nonabsorbing (helium or vacuum) atmosphere.

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.

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.

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.

Pulse-amplitude discriminators are useful in nuclear counting to separate signals of greater amplitude from a background of unwanted or noise signals of lesser amplitude. As used here, the term "fast" implies circuits capable of responding to pulses between a nanosecond and a microsecond in duration. An ideal discriminator would produce for any incoming signal whose amplitude is greater than a threshold bias level, an output pulse of constant amplitude, duration, and delay with respect to the input signal, regardless of the incoming duration and rate; and for signals less than the threshold, zero output.

"Design and fabrication techniques were improved so that the large area image intensifier now performs well in image intensifier systems for photographing nuclear tracks. Two successful samples meeting most of the objectives were completed and started in circulation among members of the AEC Image Intensifier Committee for evaluation in systems to record nuclear tracks. Except for a reported long decay in the P-15 phosphor performance was quite good. Resolution, gain, and background requirements were met. Magnification was still high (1/6.5 compared to a design objective of 1/8) but can be lowered to 1/8 by a straightforward mechanical change. Evaporated layers of thallium activated rubidium and cesium iodide were improved and further evaluated. Improved control of color and persistence was obtained. Efficiency as high as 1/3 that of P-11 phosphor was obtained in some samples. The current test series confirmed earlier results that an increase in cesium iodide content shifts the emission spectrum towards the yellow. Burn-resistance and light output was poorer for the cesium enriched phosphors while decay time was decreased.

"A survey of the current theoretical picture of plasma containment in cusped magnetic configurations is presented together with a mention of the points of contact which exist or might soon be made to exist with experiment. A theory of containment was developed which is applicable to the whole range of plasma densities from a tenuous plasma in an essentially vacuum magnetic field to a fully developed plasma which completely excludes the magnetic field from its interior. Also presented are cursory accounts of the situation with regard to stability, cyclotron radiation, and methods of creating this type of plasma configuration."

Highly radioactive materials have to be examined behind massive shielding to protect personnel from the intense beta and gamma fields. Experience has shown that much maintenance time can be saved by mounting equipment to cell plugs so that a single machine can be removed without the necessity of shutting down the entire cell operation. Metallographic specimen preparation and photography have been reduced to an entirely remotized procedure. Various etchants have been tried and cathodic vacuum etching has proved more satisfactory than chemical procedures. Cathodically vacuum etched surfaces are much more stable than chemically etched ones and are in various other ways more suitable for remote metallographic study. Radiation darkening of objectives and other parts of the optical system is a major problem in remote metallography. The limited amount of work done to date has not fully explained the effects of irradiation on metallographic structures. Micrographs are presented of some materials after various degrees of irradiation.