A study was made to determine the magnitude of the velocities existing in the various slurry pumps currently in use and to determine possible methods of reducing the velocities in order to obtain longer life. The maximum velocities of the lOOA, 200A, and 300A pumps are between 39 and 53.6 fps with the exception of the lOOA absolute discharge velocity which is 80.6 fps. For large slurry pumps, it is recommended that lower speeds be used in order to reduce the impeller relative velocities. (auth)

This bibliography of the unclassified literature on radioactive waste treatment and disposal has been compiled from references published in the Nuclear Science Abstracts Volume 11, No. 11 (June 15, 1957), through Volume 12, No. 12 (June 30, 1958). The bibliography brings up to date a previous bibliography published as CF 57-8-138. (auth)

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The deflection and stresses of a medel of the Yankee lower core support structure, conslstlng of two clrcular perforated plates joined together by a clrcular reinforclng rib and 76 cylindrical spacers, were obtained experimentally. The relationships between the tests on the model and reference design were determined by an application of dimensional analysis. Experimental investigations are described in which various design parameters were determined and the structural rigidity of the assembly was obtained. A rational methed of semitheoretical analysis of the problem is suggested based on Reissner's small deflectlon theory which takes into account the effect of transverse shear and normal stress deformation. (auth)

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Thorium oxide is formed by the calcination of thorium oxalate precipitated under carefully controlled conditions. Material is produced with mean particle diameters of 1 to 5 mu . Some of the thorium oxide had uranium added to it by decomposing uranyl carbonate on the thorium oxide followed by calcination. Most of the oxides prepared were calcined to 1000 deg C or more and size classified to remove particles greater than 10 mu . The oxides were prepared in 150-lb batches, with a complete cycle requiring 24 hr. (auth)

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The differences in the sizes and shapes of crystals formed during four common types of thermal gradient mass transfer experiment are discussed These difference are illustrated with photograped for each case considered. A mechanism is advanced to accoutn for the of mass transfer experiment. Based on an idealized icting the stabe under various experimental conditions. Numberical n graphical form. (auth)

Critical experiments are described, and the hazards attendant to these experiments are evaluated for a gascooled water-moderated reactor design. Shutdown control of the critical assembly is achieved by cadmium control blades and by dumping the water into a storage tank. The maximum normal rats of reactivity addition is limited to an estimated 0.04 per cent per sec for all remotely controlled operations. The system is interlocked to insure that safe operational procedures are followed, Hazard calculations are made to determine the dosage from direct radiation, fall-out, and inhalation from a radioactive cloud resulting from an accident. The exclusion area is shown to be adequate for even the maximum hypothetical accident. (auth)

It is the purpose of this report to review our experience with recombiners under actual reactor operating conditions, and to discuss new developments in the field.

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Evidence is presented that the hot-zone attack of nickel-base alloys in contact with fused fluorides occurs by a grain-boundary diffusion process. Predictions based on tbe grain-boundary diffustion model are shown to copmpare favorably with existting data. Certain anomalies are pointed out with regard to the corrosion of Inconel by Fuel No. 20 (NaF-UF/sub 4/-ZrF/sub 4/) and tests which would lead to a better understanding of fused-salt corrosion are outlined. (auth)

The program of neutron activation analysis service at Oak Ridge National Laboratory is described. The techniques used, the limits of measurement, and the general applications of the method are discussed. (T.R.H.)

By carefully controlling the agitation, temperature, concentrations, and reagent addition rate, it was possible to produce a thorium oxide product within 0.3 mu of any selected size between 2.0 and 3.0 mu . The rate of addition of oxalic acid to a thorium nitrate solution was the variable used in the current series of tests. (auth)

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An analysis was made of the problems of control and measuremeat of specimen temperature and heat generation in a NaK-filled capsule containing a fuel specimen. A specific problem is used in this report to demonstrate the large uncertainties normally encountered even in capsules containing thermocouples. This analysis indicates that an improvement by a factor of more than three (i.e., from an uncertainty of plus or minus 7O F to plus or minus 2O F in the example used) may be obtained by use of a differential- thermocouple heatflow meter and by use of a precision thermocoupleplacement clip. Since the irradiation damage suffered by fuel specimens is sensitive to small changes in temperature and burnup, improvements in precision in irradiation testing are of great importance in fuel studies. If the indicated improvement of precision by a factor of three is actually obtained when capsules of this design are irradiated, the experimenter will be able to draw much more reliable conclusions from a given testing program. (auth)

The amount of hydrogen normally present in zirconium and zirconium alloys suffices to reduce their ductility greatly in an impact test at room temperature, after slow cooling from 6OO deg F. Quenching from 6OO deg F or above gives high impact strength, as does removal of hydrogen by hightemperature vacuum aanealing. The evidence on hydrogen embrittlement, the diffusion, solid solubility, and equilbrium pressure of hydrogen in zirconium the microstructure, and the effects of hydrogen and heat treatment on the mechanical properties of zirconium are discussed. (auth)

Due to extended low-temperature operation of the KAPL30 carbon steel thimble in the Materials Testing Reactor, a radiation damage evaluation was undertaken. Radiation damage in carbon steel may not be annealed under lowtemperature operating conditions. The data used in the evaluation are presented, and an extension of thimble life to 16 reactor cycles is recommended, subject to review if further low-temperature operation occurs. (D.E.B.)

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