The KEWB Program is devoted to the study of the dynamic behavior of homogeneous type research reactors. The objectives of this program include studies to develop better and more complete understanding of phenomena which contribute to the kinetic behavior and the inherent safety of the water boiler reactor. The approach to the objectives has heen to construct a prototype 50 kw homogeneous reactor with the necessary auxiliary apparatus and to study the transient behavior of the system as a function of the more significant parameters which affect this behavior. These include the amount of reactivity release, rate of reactivity release, initial core pressure, initial core temperature, initial reactor power, and void volume above the core. Data are plotted. (auth)

A total of 270 animals of 5 species was exposed by inhalation to compounds of zirconium for 6 hours per day, 5 days per week. One group of animals was exposed to ZrO{sub 2} at an atmospheric concentration of 75 mg. Zr/m{sup 3} for 30 days; another, to 11 mg. Zr/m{sup 3} for 60 days. A third group was exposed to a mist of ZrCl{sub 4} at a level of 6 mg. Zr/m{sup 3} for 60 days. Zirconium oxide produced no significant changes in mortality, growth rate, blood nonprotein nitrogen or fibrinogen, urinary protein, hematological values or histological structure. Zirconium tetrachloride at 6 mg. Zr/m{sup 3} gave questionable changes in blood hemoglobin concentration and red cell counts of dogs and a slight increase in mortality of rats and guinea pigs. Inhaled zirconium compounds deposited primarily in the lung and pulmonary lymph node, with a fraction of a per cent in the bone and considerably less in the soft tissues. (auth)

This report presents results on radiation monitoring from the radiological sciences department for January, 1955. Information is presented concerning radioactive effluent releases, personnel skin contamination, air sampling, and general radiation monitoring from the facilities.

This quarterly progress report gives an overview of the University of Rochester Atomic Energy Project for April 1, 1950 thru June 30, 1950. Sections included are entitled (1) Biological Effects of External Radiation (X-rays and gamma rays), (2) Biological Effects of External Radiation (Infra-red and ultraviolet), (3) Biological effects of radioactive materials (polonium, radon, thoron, and miscellaneous project materials), (4) Uranium, (5) Beryllium, (7) thorium, (8) fluoride, (9) zirconium, (10) special materials, (11) Isotopes, (12) Outside services, (12) Project health, (13) Health physics, (14) Special Clinical Service, and (15) Instrumentation (Spectroscopy, electron microscopy, x-ray and nuclear radiation detectors, x-ray diffraction, and electronics).

A general survey is presented of information in the uranium alloy field. Emphasis is centered on alpha uranium-rich alloys of special interest as uranium- base fuel element materials. The systems treated include uranium-molybdenum, uranium-silicon, uraniumzirconium, uranium-niobium, and uranium-zirconiumniobium (high uranium compositions). The uraniumfissium alloys are discussed in relation to their projected applications as fast reactor fuels. Equilibrium diagrams, transformation kinetics, and other pertinent data are presented for the uranium plus fissium'' element systems, e.g., uranium-ruthenium, uranium-rhodium, uraninum-palladium, and uraniummolybdenum-ruthenium. The properties covered include constitution phase diagrams, metallographic structure, physical and mechanicaly properties, transformation kinetics, crystallographic structure, thermal cycling, ad irradiation stability (where pertinent). Correlations between microstructure, heat treatment, and dimensional stability are emphasized, with particular reference to the U-2 wt.% Zr, U-5 wt.% Zr, and 1 1/2 wt.% Nb alloys. A discussion of the role of alloying and heattreatment in improving the dimensionaly stability and corrosion resistance of uraaium is presented, and an evaluation is made of the present status in attaining these objectives. (auth)

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The experimental program performed in the SRE auxiliary and main primary galleries was part of a program to determine the adequacy of the shielding configuration for the SRE. The work discussed in this report is concerned with analysis of neutron streaming at coolant pipe penetrations of the reactor vessel, analysis of the shielding required, testing and evaluation of recommended shielding, and measurement and correlation of neutron streaming in labyrinths with theory. The activation analysis method using zinc sheets which was developed for the program of determining thermal neutron streaming in the SRE primary galleries was proven to be versatile, accurate, and reliable. A modified form of the theoretical method of Price, Horton, and Spinney, used to determine neutron scattring through labyrinths, was found to agree favorably with the experimental results obtained from the SRE primary galleries. The theoretical attenuation method used no determine the neutron shield configuration installed in the auxiliary primary gallery was found to give an overestimate of the actual attenuation properties of this shield. The neutron shield configuration installed in the auxiliary primary gallery proved to be adequate in reducing the thermal neutron streaming flux to an acceptable level. It is concluded that both SRE primary galleries …

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Papers are presented in the following major categories: applied metallurgical research, natural-uranium metallic fuel elements, enriched-uranium metallic fuel elements, nonmetallic fuel elements, corrosion of U alloys, irradiation effects on U, its alloys, and its compounds, and Pu fuel elements. (M.H.R.)