The objective of the Accurate Nuclear Fuel Burnup Analyses program is to develop more accurate methods for burnup analysis for general use than the current method of analysis of Ca-137 or Sr-90. The program will require from three to five years of effort.

The report includes a summary of the results of computations to data on post-test dose rules from activated materials comprising system components and support structure.

The adsorption of ethane, ethylene, and acetylene on clean iridium in a field emission microscope was found to cause characteristic changes in the work function of the iridium surface. Further changes, which were time and temperature dependent, resulted when such surfaces were heated. Flash filament experiments showed that the changes in work function upon henting are due to desorption reactions and that the desorbed product consists principally of hydrogen. By assuming a linear relationship between surface coverage and work function, it was possible to determine the desorption kinetics from the observed rates of work function change at various temperatures. The results were consistent with a mechanism involving stepwise surface dehydrogenation in which a pair of hydrogen atoms is removed from the hydrocarbon molecule in each step, followed by desorption of the adsorbed hydrogen. At very high temperatures the remainlng carbon atoms are removed, presumably by evaporation. (auth)

This report addresses the concepts of the Aeroject-General Corporation Reliaibilty Handbook

Annual report submitted by the Girl Scouts of the United States of America to Congress describing highlights from 1961, activities, finances, organizational leadership, and other information about scouting programs.

Thirty-seven articles are included; separate abstracts were prepared for 24. Two articles on the effects of radiation on methionine sulfonium compounds and on silica gel structure and the chromatographic process were previously abstracted in NSA. The articles not abstracted include information on life span and fertility of irradiated mice, biochemical studies on Cu(I,II)-peroxy theory of radiobiological effects and their modification, studies on the giant amoeba, low temperature storage of epoxy resins used for embedding in electron microscopy, method for obtaining fixing solutions osmotically equivalent to physiological saline solution, and P/sup 32/ uptake as an indicator of tritiated thymidine toxicity. (P.C.H.)

BS>Laboratory studies on the processing of graphite-base fuel elements containing pyrolytic carbon- or Al/sub 2/O/sub 3/-coated particles are reviewed. Potential processes for recovering U and Th from irradiated elements include grinding followed by acid leaching, and, burning and subsequent dissolution of the oxide ash. Disintegration in 90% HNO/sub 3/ was briefly evaluated as a method for determining the integrity of coated particles dispersed in graphite matrices. (auth)

Nine samples of ThO/sub 2/ -UO/sub 2/ prepared as part of the solgel process development studies showed no consistent effects from small variations in several process parameters. The reaction of methane and copper oxide was studied. Engineering studies of the continuous dissolution of simulated U-Zr-Sn fuels in 6.5 M NH4F, 0.6-1.0 M NH/sub 4/NO/sub 3/, 0.1 M H/sub 2/O/sub 2/ were continued in modified 6-in.-dia. equipment. A total of 1642 kg of U from NaK bonded SRE Core I fuel rods wad dejacketed to date/su Initial operability tests of the 250 ton prototype shear unit showed a number of minor modifications are warranted. Center tube temperatures measured in a vertical 64 tube electrically heated simulated fuel element bundle were very near those previously obtained in the horizontal position. A 304 SS tube containing eutectic NaK was dissolved by HF in fused saIt at a tube wall penetration rate of approximates 2 mils/hr. Partial differential equations were derived from the concentration of unreacted UF/sub 6/ as a function of time and position in a sphere of NaF during sorption of UF/sub 6/. Calcium nitrate solution was added directly to the pot calciner during Purex feeding to give smoother operation of the …

High-speed motion pictures of boiling water flow patterns in conditions of forced flow at 1000 psia pressure in a vertical heated rectangular channel were taken at mass velocities from 50 to 400 lbs/sec-ft/sup 2/, fluid states from 170 Btu/lb buik enthalpy of subcooling to 0.68 bulk steam quality, and heat tluxes up to and including the critical heat flux level. An objective of the work was to make the results available for continued experimental and theoretical investigation of the critical heat flux phenomenon in forced-flow bulk-boiling systems. The results are intended to be applicable to design and development of nuclear power reactors employing high-pressure boiling water as a working fluid. Motion pictures show substantial, but not indisputable, evidence that the general arrangement of the flow, in conditions of bulk boiling, at heat fluxes near and including the critical heat flux level is characteristically a wavy turbulent liquid film, in which there is vapor formation, flowing along the channel walls with the balance of the liquid being carried as either dispersed droplets or as an emulsion with the vapor in an adjacent more rapidly and steadily moving core. (auth)

This report addresses the development and evaluation of beryllium oxide-boron bodies containing up to five weight percent boron for burnable poison, poison reflector and shielding applications.

Specimens of 0.428 to 1.18 in. dia. BeO were irradiated at 1.4 x 10/sup 20/ to 2.8 x 10/sup 21/ fast neutrons/cm/ (>1 Mev), with irradiation times of 2.03 x 105 to 5.60 x 106 sec, at 110 to 1025 C, and gamma heat generation rates of 18 to 25 w/g. The greatest damage appeared in bodies irradiated for high neutron doses at low temperatures. Greater doses could be tolerated at higher temperatures. Specimens irradiated at 110 deg C powdered at an accumulated dose of 1.5 x 10/sup 21/ 1.1 x 10/sup 21/ neutrons/cm/sup 2/ and at 737 deg C at a dose of 1.6 x 10 /sup 21/ neutrons/cm/sup 2/ remained intact. Specimens irradiated at 827 to 950 deg C at a dose of 2.1 to 2.6 x 10/sup 21/ neutrons/cm/sup 2/ fractured. Changes in linear dimensions up to 4% were observed. X-ray diffraction measurements revealed changes in the c lattice parameter up to 7 x 10-3 DELTA c/c0 for material irradiated at 110 deg C but only 1 to 2 x 10-3 DELTA c/co at 444 to 1025 deg C. The DELTA c/c0 value appeared to saturate at a dose of 3 x 10/sup 20/ neutrons/cm/sup 2/ in …

The application of SNAP systems to electric propulsion was investigated. A review is given of the basic analysis involved in establishing optimum power levels and payload capabilities for electric spacecraft, and several typical missions are analyzed to determine the usefulness of the SNAP systems which are under development or systems which are based on the current SNAP technology. In general, it is found that SNAP power units in the range of 60 to 180 kw offer significant mission capability when used in conjunction with initial spacecraft weights of about 10,000 lb in a low-level orbit. (auth)

Experimental determinations of the ionic and electronic emission characteristics of tantalum, tungsten, rhenium, and iridium cathodes in vapor thermionic converters are compared. It is shown that tantalum provides superior thermal ionization qualities at high pressure compared with tungsten, rhenium, and iridium. High electronic current densities may be obtained from cesium on rhenium and cesium on iridium at much lower cesium vapor pressures than for tantalum or tungsten. (auth)

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A Fortran program is described for calculating the absorption correction for application to single crystal x ray or neutron intensity measurements. The program is available in the form of symbolic punched cards. InstrucPions are included. (J.R.D.)

The Hall mode of operation utilizes a signal derived from the magnetic field of an experimental magnet to provide the power supply regulator with the information necessary for it to regulate the magnet current. Regulation of the field to 0.1% is possible with the Hall probes and regulators used at the Cosmotron. The Hall Effect is a phenomenon whereby the voltage developed across a semiconductor or metal is a function of the current through the material and the magnetic field intensity perpendicular to the direction of current flow. Circuitry is required to maintain the probe at a constant temperature and to maintain a constant Hall current. The output Hall voltage is linearly related to the magnetic field with its absolute value being determined by the level of the Hall current. Instructions for installation and operation of the Hall probes are given. (H.G.G.)

Report that summarizes multiple laboratories' reports on global fallout deposition. Reports include data on Strontium-90 deposition recorded by the Health and Safety Laboratory, data from other laboratories, related interpretive reports, and recent publications related to fallout.

This phase of the program is concerned with irradiation of fuel assemblies to determine central temperature limitations.

During the eighth quarter the instrumented assemblies were removed from VBWR and examined for effects of the exposure to reactor conditions. Also during this period the Big Rock developmental fuel assembly design was completed and a topical report was issued. A summary of progress by task is presented here.

>A Knudsen effusion cell assembly is described which was designed For study of high-temperature vaporizatibn processes with a time-of-flight mass spectrometer. The cell is heated by electron bombardment, and temperatures up to 3100 deg K were reached. (J.R.D.)

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A coextruded 2-inch-diameter tubular fuel element of U-2 wt% Zr alloy clad with Zircaloy-2 was irradiated in the Vallecitos Boiling Water Reactor to 1280 Mwd/t burnup with a maximum core temperature of 433 deg C. The purpose of this irradiation was to determine the dimensional stability of the alloy under conditions approaching those contemplated for D/sub 2/O-cooled power reactors. Successive dimensional measurements revealed a sharp change in swelling rate between 700 and 1280 Mwd/t burnup. The amount of swelling increased during this interval from 0.8 to 3.6% (0.7% final cladding strain). This test indicated that the dimensional stability of the U-2 wt% Zr alloy is inferior to that of unalloyed U irradiated under similar conditions. (auth)

Oxygen, nitrogen, and nitric oxide gases were passed through a system consisting of a tungsten filament, an ion gauge, and a mass spectrometer. The ion gauge recorded total pressures and the spectrometer recorded partlal pressures of O/sub 2/, N/sub 2/, NO, CO, COa, and H/sub 2/O. From the way these pressures changed with filamert temperature, the rates of conversion of O/sub 2/ to volatile tungsten oxides and O, and of NO to volatile tungsten oxides N/sub 2/ , O/sub 2/, and O were computed. The time rate of resistance change in the filament was used to compute the rate of conversion of tungsten to tungsten oxides. The filament temperatures ranged from 1950 through 2600 deg K and gas pressures ranged from 10/sup -8/ to 10/sup -6/ atm. For the tungsten-oxygen reaction, the rates of tungsten and oxygen loss were found to depend upon oxygen atom concentration on the surface. The rate of oxide power, depending upon the concentration of oxygen atoms on the surface. The reaction rate at constant oxygen pressure decreases with increasing temperature. For calculational purposes, the tungsten oxygen gas moleeules were assumed to be WO/sub 3/ only, though WO/sub 2/ and WO are other possible products. The …