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.

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.

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

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.

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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 …

The IBM 7090 program Murgatroyd is a revised and extended version of the IBM 704 program PET-I, which solves (by a fifth-order Runge-Kutta procedure) the coupled firstorder differential equations for power, delayed neutron concentration, and temperature in a one-region reactor as a function of time, given an input reactivity variation represented by a series of linear ramps. The basic extensions were those which were necessary to include the effects of the separate heat capacities and temperature coefficients of the fuel sait and graphite in the MSRE, and of heat transfer between the fuel and graphite. In addition, the input and output sections of the previous program were modified to facilitate the use of the program in extensive parameter studies, and a calculation of the pressure rise in the core was included. Typical running times are of the order of l2 milliseconds per time step; a calculation of a 30-second power history using a 10 millisecond time step requires about 36 seconds of machine time. (auth)

The analysis of gamma-ray spectra measured with a scintillation counter with an anticoincidence annulus is described in detail. In particular the problem of the determination of the energy and intensity of gamma rays from such measurements is considered. The shapes of the full-energy peaks in observed complex spectra are studied and an attempt is made to justify their description in terms of a Gaussian response function. The details of the statistical analysis of complex gamma-ray spectra are given and, finally, procedures which have been used to confirm the validity of error estimates in energy and intensity measurements are described. (auth)

The hazards connected with the handling of actinide elements are surveyed. Emphasis is placed on Th, U, Np, and Pu. It is pointed out that the chemical toxicity of the actinides is usually minor when compared with radiochemi cal toxicity. Inhalation and ingestion are the important routes of entry but direct injection into the blood stream through wounds also requires consideration. Special enclosures, such as glove boxes, function primarily to minimize the risk of inhalation and aid in confinement. The external hazard from actinide elements, primarily due to gamma and fast neutron emission, varies considerably with the element and its source. Irradiated actinides, such as Th and Pu, usually show an increase in the external hazard from gamma radiation with extent of irradiation. (C.H.)

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.)

A gamma pinhole camera was devised to permit a nondestructive examination of irradiated specimens while still in sealed capsules. The camera was designed such that a complete experiment may be withdrawn from an irradiation facility, the specimen autoradiographed, and the experiment then reinserted if so desired. The pinhole aperture is 0.020 in., and the source to pinhole block is 4 ft. The image-to-source sizes are a one-to-one ratio. The resolution of the image is 0.03 in. (auth)

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)

Supplement to ANL-5607. Alterations and additions made to the Experimental Boiling Water Reactor (EBWR) plant to permit operation at power levels up to I00 Mw(t) are described. Topics covered include over-all system modifications and additions, nuclear component modifications and additions, and reboiler plant component description. (M.C.G.)

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 …

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)

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.)

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 …

S>The problem of fracture of solid cylinders of BeO due to stresses induced by transient temperature differences is considered. The stress analysis for this case, the appropriate fracture theories, and the related properties of BeO are presenied and used to estimate the conditions under which solid cyIinders of BeO should crack. On the basis of available data and assuming that the maximunw principal stress controls fracture, BeO cylinders should fail on quenching from 1000 C if r h (radius of cylinder times film coefficient) is greater than 0.01 cal sec/sup -1/( deg C)/sup -1/ cm/sup -1/. An additional assumption used in this calculation w; that the tensile strength is 30,000 psi and independent of temperature over the temperature range under consideration. A testing program required to evaluate BeO for use in reactors is outlined in general terms. (auth)

Additional runs were made in the 6-in.-dia. separation column. The kinetics of the methane --copper oxide reaction was investigated in deep bed tests. The work on the development of the shear included a satisfactory method of ng, preliminary test of an outer gag faced with rubber, and a metallic inner gsg contoured to the shape of a sheared assembly. The mechanical dejacketing of the SRE Core I fuel, NaK-bonded, stainless steel-clad uranium slugs, was successfully completed. The effective therrnal conductivity of a packed bed of 0.023-in. steel shot was approximately 0.33 Btu/hr- deg Fft at 200 deg F. Flow capacity for the compound extraction scrub column equipped with sieve plates (0.125-in.-dia. was determined. Average waste calcination rates for Purex were higher by a factor of 1.5 to 2.0 than rates for TBP-25. (auth)

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)

>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.)

For presentation at International Atomic Energy Agency Symposium on Reactor Safety, Vienna, Austria, May 14The Westinghouse Testing Reactor (WTR), a privately owned 60 megawatt tank type reactor, underwent a fuel element failure on April 3, 1960. A meltdown of one fuel element occurred causing the spread of fission products through the reactor cooling system. There were no casualties or overexposures. The cause of the accident could not be established beyond a reasonable doubt, but the possible cause appeared to be a cladding failure at a bonding defect. The Stationary Low Power Reactor No. 1 (SL-1), a 3 megawatt prototype reactor, underwent a nuclear excursion at the U. S. Atomic Energy Commission's National Reactor Testing Station (NRTS), Idaho, on January 3, 1961. The three military operators on duty at the time received fatal injuries and the core experienced severe damage. Large amounts of radioactivity were released inside the reactor building; however, release of radioactivity from the building to the atmosphere was slight. This was the first fatal reactor accident in the history of reactor operation in the United States. Prior to the accident, the reactor had operated for 931 megawatt days, approximately 40% of its core life. Primary efforts subsequent to …

Experiments were made using a potassium plasma cell with a Ta emitter and a Ag-plated Cu collector. The r-f frequencies, rms voltages, power output, and other quantities were measured under various conditions of emitter temperature, potassium vapor pressure, and d-c and r-f loads. Ion and electron densities were calculated and compared with the oscillations occurring. (D.L.C.)

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)