"Progress is reported in an evaluation of fission product concentration in rain as a function of time, location, and meteorological setting. Data on rainfall collected at Westwood, N. J., were analyzed for information on the mechanisms of fallout deposition, seasonal variations in fallout, the stratospheric residence time of W/sup 185/ resulting from Operation Hardtack, and the accuracy of pot samplers for sample collection. Data from other collection stations were also analyzed for consistency with Westwood data."

"The state-of-the-art of heat exchangers for gas-cooled reactor primary circuits is established by describing steam generators, primary heat exchangers, recuperators, and coolers of a number of gas-cooled nuclear projects, and by listing plant and exchanger main characteristics in three summery tables. Information is based in part on references indicated and in par+ on data from manufacturers. The availability of suitable heat exchangers is represented in the form of 35 Data Sheets submitted by manufacturers in response to our request. A list of manufacturers and their addresses is appended."

"The potential of closed-cycle gas turbines for producing a highly efficient nuclear power plant is discussed. Such turbines are being developed for three applications: the HTRE program (Heat Transfer Reactor Experiment) for nuclear aircraft propulsion, the MGCR program (Marine Gas Cooled Reactor) for nuclear marine propulsion, and the ML-1 (Mobile Low-Power Gas-Cooled Nuclear Power Plant) for nuclear electric power generation in an Army mobile power plant as part of the Army Gas-Cooled Reactor Systems Program (AGCRSP). Some characteristics of several non-nuclear gas turbines as well as gas turbine prime movers of 18 U.S. gas-cooled nuclear power plant projects were examined. Turbine and compressor performance, performance improvement, full-load and part load operation, maintenance, component life, and reliability are discussed. Consideration is given to factors affecting structural integrity of turbomachinery, such as choice of proper materials, vibrations, cooling, and construction features. The material reported is based on information obtained in part from the 155 references included and in part from the data requested from some 60 manufacturers."

The objective of the study which is being carried out under contract AT(30-1)-2477 is the exploration of all aspects of research in water resources and supply to determine the potential for using radioisotope technology in this research. Problem areas in the application of tracers in this research are being investigated through the evaluation of past experimentation with radioisotopic techniques and through discussions with those who are active in this work. A series of suggestions relating to these techniques will de drawn up to indicate which techniques should be developed further in order that more extensive applications may be found for them.

The study which has been carried out under Contract AT(30-1)2477 has as its objective the review of all work which has been done on the application of radionuclear techniques to research in water resources and supply, the evaluation of this work, and the suggestions of specific experiments which must be performed if these applications are to be extended.

Nuclear processes are random in character, and, accordingly, are amenable to statistical treatment. In 1905, shortly after the discover of natural radioactivity, E. Von Schweldler showed that the analytical description of the decay distribution of radioactive substances followed from probability considerations regardless of the mechanism involved in the process of atomic disintegration.

"The visible absorption spectra of VA3, CrA3, MnA3, FeA3 and CoA3 (A=C5H7O2, the acetylacetonate anion) are reported. The interpretation of the data in respect to the symmetry and strength of the ligand fields is discussed, with special attention to the presence and magnitudes of trigonal components in ligand fields and its consistency with certain results of paramagnetic trigonal fields of appreciable magnitude are present."

Several different types of experimental facilities have been evaluated to determine the most suitable and economical means of demonstrating the technical feasibility of the Pebble Bed Reactor concept. The criteria for demonstrating technical feasibility are: 1) bulk irradiation of fuel elements in order to obtain statistical data on performance, 2) Maintenance of system activity at specified levels, and 3) Feasible maintenance procedures. An additional criterion, which is required to achieve breeding in the full scale plant is - 4) Demonstrate the mechanics of continuous refueling under load.

"The experimental technique was checked out and the equipment put in working order for the study of the capacity and efficiency of the hydraulic cleaning of coal by water fluidization. The method to determine operating capacity consists of determining the segregation rate by dynamic tracing of radioactive mineral impurities of various size and density ranges, that are injected into the fluidized bed of coal. The equilibrium position of the injected tracer in the fluidized bed of solids is also determined. Obtaining capacity and efficiency data, as needed for design of commercial units, is very much less expensive and much more rapid than operation of a continuous flow pilot plant to get the same data. The required tracer solids were prepared by neutron irradiation of selected fractions of mineral impurities and the experimental work with these tracers is now in progress."

Conclusions from the study: "Radioactive dusts are carcinogenic, and can cause cancer of the lung. complete dose response curves have not yet been determined. All the parameters that render this demonstrably toxic material (radioactive dust) have not yet been evaluated. It is strongly suggested by the experimental data that duration of radiological insult to the lung is an important factor in eliciting lung cancer. The atmospheric tolerance concentrations now in use seem to afford little margin of safety."

"Properly designed and fitted respirators have been effective devices for reducing the inhalation of toxic aerosols. The degree of protection afforded by these devices has not been quantitatively measured under actual work conditions except by bioassay or other elaborate techniques. This report describes a new quantitative technique for evaluating over-all respiratory performance under conditions comparable to exposure to highly toxic radioactive materials such as plutonium and non-radioactive materials such as beryllium."

"A new phenomenon which can, under certain circumstances, account for anomalous magnetic and spectral behavior of planar nickel(II) complexes has been discovered. This is a molecular association of the solute molecules in solvents of low coordinating power. It is shown that the magnetic moment and spectrum of bis(2.6-dimethyl1-3,5-heptanediono)nickel(II), Ni(DIBM)z, dissolved in toluene, are dependent upon both temperature and concentration.

In 1947 Bauer, and later independently Huntley (1948), pointed out that the helium content of iron meteorites as measured by Paneth and coworkers could be accounted for by the accumulation through cosmic-ray production rather then the decay of uranium and thorium. Bauer (1947) also predicted that the meteroitic helium should contain a significant proportion of He3. I was realized that by studying the effects of cosmic radiation on meteorites much could be learned about the history of meteorite and cosmic radiation. Chemical and instrumental techniques have been developed for the isolation, purification, and measurement of cosmic-ray-induced C14 in both stone and iron meteorites. The isolation of carbon from the silicate materials is done by fusion in an oxidizing flux in a vacuum system. From the iron meteorites the carbon is recovered by the decomposition of the metal in nitric acid in a closed system.

Procedures for the separation and concentration of microgram to nanogram amounts of thallium from gram amounts to galena and meteorite metal, sulfide, and silicate phases were developed and are described. The thallium is extracted from aqueous bromide of chloride solutions of moderate acidity using diethyl ether. A device for elimination of the large volumes of solvent by dropwise evaporation is described. Organic matter in the residue is destroyed by treatment with aqua regia, and the thallium is the residue is converted to the nitrate for spectrochemical or mass-spectrometric examination. The presence of thallium in the residue is tested by Rhodamine B. test.

"Various existing circulator types suitable for primary loops of gas- cooled nuclear power plants are discussed. Operating characteristics, drive systems, structural problems, and maintenance questions are analyzed. The present state of the art is established and requirements, availability, development areas, and limiting factors are indicated. Several existing test- loop gas circulators are included in the general discussion."

"The study of the toxicity of Ra and MsTh(Ra/sup 228/) in humans was continued. Several Thorotrast cases were also examined. Physical and clinical studies were made on 151 persons. In all cases possible gamma ray measurements were made of Ra and MsTh decay products retained in the body, alpha -ray measurements of Rn and Rn/sup 220/ in breath, a complete medical history was taken, a complete x-ray examination was made of the skeleton, and urinalysis, hematological, and blood chemistry studies were made."

"The study of the toxicity of Ra and MsTh(Ra/sup 228/) in humans was continued. Several Thorotrast cases were also examined. Physical and clinical studies were made on 151 persons. In all cases possible gamma ray measurements were made of Ra and MsTh decay products retained in the body, alpha -ray measurements of Rn and Rn/sup 220/ in breath, a complete medical history was taken, a complete x-ray examination was made of the skeleton, and urinalysis, hematological, and blood chemistry studies were made."

"Helium, nitrogen, carbon dioxide, and other gases suitable as reactor coolants were evaluated. It is shown that because of the helium conservation program, recently authorized by legislation, sufficient helium will become available for domestic power plants and for the requirements of the Euratom group. Tables of thermodynamic properties for helium and molecular nitrogen were computed from the Beattie-Bridgman equation of state. Specific enthalpy, specific entropy, isobaric specific heat, specific heat ratio, compressibility factor, specific volume, and acoustic velocity are tabulated over the range helium and molecular nitrogen are given."