EURIPUS-3 calculates the one-dimensional spatial density of neutrons slowing-down past a given energy in an infinite homogeneous medium consisting of hydrogen and one other isotope with arbitrary mass and energydependent differential-elastic and absorption cross sections. DAEDALUS determines the corresponding spatial distribution of angular integrals of an arbitrary function times the vector flux density. Spatial moments of all density functions are furnished directly. Although scattering angles are calculated by Monte Carlo, the spatial distributions and, in DAEDALUS, the energy distribution are obtained partly from an analytic treatment which, besides saving tinne, enables the output to be in the form of actual density functions at specified planes and energies, rather than histograms covering finite intervals. At certain steps in the computation of both the spatial and energy distributions, part of the analytic treatment is replaced by Monte Carlo in order either to maximize efficiency and/ or to avoid round-off error. The neutron source may be monoenergetic with either isotropic or monodirectional angular distributions, or else the source may be that from deuterons bombarding deuterons. The volume displaced by a cylindrical tube from an accelerator to the source can be accounted for in the neutron first flight but not thereafter. (auth)

The diffusion of Kr/sup 85/ in two UO/sub 2/ powders was studied by performing a series of post-irradiation anneals on the powders. The emanation data were analyzed by considering the effect of sintering as well as the effect of a distribution of particle sizes within the sample. Measurements were made at 900 to 1500 deg C. The time at a temperature was between 8 and 24 hours. The diffusion coefficients for Kr/sup 85/ in the two powders are represented by the equations: D = 2.65 x 10/sup -4/ exp - 65,500/RT for UO/sub 2/ prepared from crushed UO/sub 2/ pellets and, for a chemically prepared UO/sub 2/ powder, D = 4.9 x 10/sup -4/ exp - 73,800/RT. (auth)

The requirements for multiple-coincidence counting systems with 10{sup -8}- to 10{sup -9}-sec time resolution can be met economically with presently available high-frequency transistors. The design of solid-state coincidence circuits, amplitude discriminators, and decade scalers is considered and their operation discussed. Several systems have been designed utilizing up to 180 channels from scintillation detectors.

The advantages of the use of organic liquids in fission reactors to minmize corrosion and pressure problems were studied relative to the solution of thorium in such fluids. Thorio-organic compounds were prepared from organic acids, diketones, and other chelating compounds. Salts of carboxylic and phospho- organic acids were insoluble. The chelate with dibenzoylmethane was soluble in molten biphenyl but was decomposed at 300 deg C. The general low solubility of thorio-organic compounds in nonpolar solvents can be explained by steric effects. The large thorium atom has the ability to form strong coordination complexes with adjacent molecules, leading to coordination polymers. The effect can be minimized by shielding the thorium nucleus with large organic groups such as dibenzoylmethane. The large, branched organic groups needed to impart solubility limit the maximum solubility. (auth)

ABS>A recording potentiometer was modified to provide a versatile instrument that can be applied to a variety of problems without time-consuming changes. Ranges may be selected in six spans, from 0.5 to 100 mv. No adjustments of amplifier gain are required when switching from one range to another. Zero suppression is continuously variable over a plus or minus 100 mv range by means of coarse and vernier controls. Cold junction compensation is provided for four standard thermocouples, and chart speeds from 1/2 to 16 im- ./ hr may be selected at will. (auth)

Selected components from a staianless steel nonregenerative heat exchanger removed from the U.S.S. Nautilus (SSN571) have been examined for evidence of stress-corrosion cracking. The examination was conducted on three baffle plates, all primary-face seal welds, and the tubes and the surrounding tube sheets of 7 out of a total of 35 tubes. Maximum operating temperature of the heat exchanger was 260 ction prod- F for the inlet primary water and 164 ction prod- F for the exit secondary water. Chloride content of the secondary water averaged 5 ppm, with a maximum of 15 ppm. Only one suspected stress-corrosion crack was found in the components normally in contact with the secondary water. The crack, 2.5 mils in depth, was located on a fully exposed tube. At the 95 per cent confidence level this represented a probability of finding cracking on fully exposed surfaces in 0 to 60 per cent of the rest of the tubes in the heat exchanger. Severe stress-corrosion cracking was found in tubes in the tube-sheet drain area at the juncture with the inner tube sheet at the inlet end, where secondary water seeped past the expanded tubes. Cracks were detected in five of seven tubes for a …

The conditions under which hydrogen could be quantitatively recovered from mixtures of gases by oxidation over fixed beds of CuO were investigated. The conversion of H/sub 2/ to H/sub 2/O by reduction of CuO in fixed beds increased with in- creasing bed length, temperature, hydrogen/argon ratio, and decreasing mesh size of CuO. Residence times required for 99% conversion in a 1- in.-diam. bed were 0.6 and 1.2 sec for 30% hydrogen-70% argon and 10% hydrogen90% argon mixtures, respectively, at a total gas flow of 1 l/min. The CuO used was 25-mil-diam. wires with a surface area of 0.019 m/sup 2//g. The residence time required for a given value of conversion decreased about 10% when the total flow rate was increased from 1 to 1.7 liters/min, which indicates that the reduction is mass-transfer controlled to a slight extent under the experimental conditions used. (auth)

It is recommended that the ``square pile`` concept be adopted for all disaster total control calculations, and that the basic reactor constants listed in HW-62884, except for Ball 3X local strength at the DR Reactor, be used in applying this method. Curves are included for each reactor type, indicating allowable enrichment based on appropriate local control strengths. (The reactors whose operating methods are affected by disaster total control requirements are B, D, F, and DR Reactors; the remaining piles have sufficient geometrical coverage). An example of the analytical method is included.

Tests were performed on aluminum alloys to evaluate their behavior in high-temperature, high-pressure. watercooled and -moderated nuclear reactor enviromnents. Test equipment, sample preparation. and test procedures are discussed. Aluminum nickel alloys were found resistant to disintegration for periods up to 60 days in dynamic water at 600 ction prod- F. The corrosion rates of the aluminum alloys M-388 and X-2219 at 600 ction prod- F were found to be too high to merit consideration for cladding materials. The influence of pH. gas content, and velocity of the water on the corrosion of the above alloys was evaluated. Hydrogen addition at startup appeared to increase the degree of corrosion attack on the M-388 alloy. Irradiation tests on aluminum-nickel alloys revealed that the corrosion rate increased with distance from core. In-reactor samples of M-388 exhibited less corrosion attack than out-of-reactor samples. Boiling water corrosion tests were performed on M-388 for 1612 hr at 422 ction prod- F with an average heat flux of 25,000 Btu per hrft/sup 2/. The over- all corrosion rate was 2.9 mil per yr. It is concluded that the corrosion rate of M-388 is acceptable for the specified test conditions: (1) absence of radiation: (2) demineralized water at …

Radiometric methods of analysis for magnesium and calcium have been developed as part of a program for the U. S. Atomic Energy Commission. Office of Isotopes Development, which are applicable to the determination of these elements in portland cement Both methods employ, as a precipitant, a standard solution of (NH/sub 4/)/sub 2/HPO/sub 4/ labeled with phosphorus-32. In the presence of NH/ sub 4/OH, this reagent precipitate; MgNH/sub 4/PO/sub 4/ or Ca/sub 3/(PO/sub 4/)/ sub 2/ from a solution of magnesium or calcium ions. The reduction in the radioactivity level of the labeled phosphate solution after precipitation serves as a measure of the phosphate reacted and thus a measure of the quantity of magnesium or calcium present. Studies have been made of the effects of reagent concentration, NH/sub 4/OH concentration, and other experimental variables. The interference of other elements present normally in portland cement and its raw materials has been determined. The concentration ranges for highest accuracy have been found to be 5 to 15 mg of MgO per 100 ml and 15 to 30 mg of CaO per 50 ml. (auth)

Cobalt samples frequently are irradiated in nuclear reactors to produce gamma sources and can be irradiated as integral flux monitors because of the long half-life of the isotope produced. At the present time a small cobalt sample is being irradiated within the KW Reactor Snout facility for future use as a radiographic source for inspection of finished product in the Chemical Processing Department. Analysis was made to estimate the buildup of activity in this sample; the general equation may be of interest and value for other cobalt sample irradiations.

An evaluation of a modulator flux sensitive playback head to be used with an analog magnetic recorder for nuclear pulse information storage was made. The modulator head was found unsultable. A pulse stretching unit was constructed which takes pulses from a standard linear pulse amplifier and provides an output signal suitable for driving a recording head. (For preceding period see ARF-1151- 3.) (C.J.G.)

The radial temperature around a sodium reactor heater assembly submerged in water is calculated using a model of the heater cross section found by conformal mapping. Thermocouple readings were also analyzed. When the heat flux is 5 x 10/sup 5/ Btu/hr-ft/sup 2/, a radial temperature drop of about 680 deg C across the center of the thermocouple well is calculated and found to be within 6% of the experimental value. Since most of this drop is across the 0.001-in. helium gap between the heater and its sleeve, it is concluded that the thermocouple will have to be bonded to the sleeve for dependable reading of true sleeve temperature. Drawings of the heater assembly and thermocouple are given. (D. L. C.)

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Analytical methods were employed to determine the maximum volume-to- stress ratio for a two-radii-contour diaphragm pump. A proposed failure criterion considers the effect of biaxial stresses on fatigue failure through. the use of the Mises-Hencky criterion for fatigue failure. By use of the proposed criterion, it was determined that an optimunn ratio of the two radii does exist, its value being dependent on the ratio of diphragm thickness to diaphragm deflection. Values for the optimum ratio of the two radii (where the ratio of radii is defined as the radius of the central pcrtion of the diaphragm contour divided by the radius of the outer pontion of the diaphragm) range from 1.94 to 7.33 as the ratio of diaphragm thickness to diaphragm deflection varies from 0.5 to 0.05, respectively. (auth)

An improved method for precipitating manganese dioxide was demonstrated that significantly increases the allowable feed rate of the Purex head-end centrifuge. The effects of several process variables are discussed. (auth)

The check valve for the Hallam Power Reactor uses a knife-edge bearing for the flapper in place of the usual journal-type bearing. Mechanical cycling in sodium at 600 deg F was used to check operation of this bearing. A total of 309 mechanical cycles was completed with no apparent malfunctioning of the valve. Measured leskage rates were 0.46 gpm at 0.93 psig, 0.73 gpm at 3.4 psig. and 0.32 gpm at 5.9 psig. (M.C.G.)

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Approximately 100 ternary and quaternary spongezirconium alloys were screened for structural and cladding applications in a natural-uranium-fueled heavy-watermolerated power reactor. The alloy additions studied included2 to 4 wt.% Sn, 0.5 to 2 wt.% Mo, and 1 to 3 wt.% Nb. The effect of 0.1 wt.% Fe and 0.05 wt.% Ni additions to the experimental alloys was evaluated. All compositions were are melted, rolled at 850 ction prod- C from a helium- atmosphere furnace, vacuum annealed 4 hr at 700 ction prod- C, and furnace cooled. Room- and elevated-temperature hardness measurements were used to estimate the tensile strengths of the alloys, while corrosion resistance was evaluated by 1000-hr exposures to static 300 ction prod- C water. (auth)

A study to improve the elevated-temperature strength of niobium by solloving has resulted not only- in greatly improved strengths at 1200 and 1470 deg F but also in the development of improved fabrication techniques for these alloys. The most important step in the fabric:ition procedure of niobium and niobium-base allows is the initial breakdown of the cast structure. The cast structure of 1.84 wt. 4 chromium, 3.21 wt.% chromium. 4.33 wt. ' zirconium, and 20.5 wt.% titanium-4.28 wt. = chromium allovs and unalloyed niobium was broken known by- forging ingots (protected from oxidation by molybdenum ciins) at 2550 deg F and rolling at 800 deg F. After the initiai breakdown of the cast structure, the alloy-s were coid roiied to a total of 95 per cent reduction with no difficulty .A second fabrication technique was employed for a second set of alloys. Unalloyed niobium and 1.29 wt. % chromium, 2.74 wt. 3 zirconium, 4.5 wt.% molybdenum, and 10 wt. % titanium-3 wt.% chromium alloys were forged and rolled at 1000 deg F to break down the cast structure and then cold rolled to 0.030-in. sheet. the sheet obtained by this technique showed moderate edge cracking. Tensite tests on the coid-worked …

Alloys containing 55 wt.% iron--22 wt.% nickel-- 17 wt.% chromium--2.5 wt.% molybdenum- 1.0 wt.% niobium-0.03 wt.% carbon-- 0.5 wt.% manganese-- 0.5 wt.% silicon with nominal additions of from 0 to 1.5 wt.% yttrium, and 36 wt.% iron-37 wt.% nickel--18 wt.% chromium--2.5 wt.% molvbdenum- 1.5 wt.% niobium-- 1.0 wt.% aluminum-0.05 wt.% carbon--0.5 wt.% manganese-- 0.5 wt.% silicon with nominal additions of from 0 to 2.0 wt.% yttrium, were prepared by vacuum- induction melting. Alloys containing 55 wt.% iron were successfully forged in air at 1900 deg F, rolled at 1850 deg F to 0.060-in. sheet and cold rolled to 0.015in. sheet. Fabrication of alloys containing 36 wt.% iron with more than 0.5 wt.% yttrium was unsuccessful. Addition of yttrium had relatively no effect on the yield and ultimate strength from room temperature to 1850 deg F. The ductility of fabricable alloys studied was increased at elevated temperatures by increasing yttrium contents. The greatest increase in ductility occurred at 1.5 wt.% yttrium. (auth)

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A drip casting process initiated to obtain zirconium castings uncontaminated by the melting process and to remove volatile impurities from the zirconium feed rod is described. A feed rod of zirconium is held above the mold, and the bottom of the rod is melted rapidly off into a mold to produce the casting. The melting process is carried out under high vacuum, so that very little atmospheric contamination can result, and some removal of volatile impurities is possible. Since no crucible is used to contain the molten metal, no contamination can result from this source. (auth)

Flowsheets are presented for the dissolution of Borax IV reactor fuel (6.35% UO/sub 2/)--ThO/sub 2/ pellets encased in 1% nickel--aluminum alloy and bonded with lead). In the preferred method the alurninum is dissolved first in boiling 2 M NaOH--1.78 M NaNO/sub 3/, with a urarium loss of approximately 0.07%. The lead and nickel are then dissolved in boiling 1.5 M HNO/sub 3/, with uranium losses of <0.2%. The oxide core is dissolved in two successive digestions with boiling 13 M HNO/sub 3/--0.04 M NaF--0.1 M Al(NO/sub 3/)) to produce a solution 0.6 M in thoriunn and 0.04 M in uranium. Dissolution of only the aluminum in sodium hydroxide or sodium hydroxide--sodium nitrate solution prior to core dissolution is unattractive since the rate of core dissolution is lowered greatly if lead is present and a product solution containing greater than 0.2 M thorium is unattainable owing to the low solubillty of lead nitrate in nitric acid-- thorium nitrate solutions. Simultaneous dissolution of aluminum and lead in mercury-catalyzed nitric acid appears costly since a mercury concentration of at leset 0.5 M is required to ensure an adequate dissolution rate. The solubility of lead nitrate in nitric acid and nitric acid--thorium nitrate solutions …