A large portion of the slug failures which occurred during 1955 were of the ``hot-spot`` type. Observation of these failures has shown them to be the result of intergranular corrosion attack of the aluminum jacket. Intergranular corrosion is presently considered to occur in water temperature above 150 C; a flow disturbance which causes non-uniform coolant temperatures is suspected as the cause of failure.The present of a cocked slug, or a bowed slug column, might provide this flow disturbance. 189-D laboratory tests have shown that flow seating the slug charge allows slugs to cock in the tube. It has also been found that these cocked slugs may be lifted to close proximity of the tube wall by the axial load on the slug column due to process water flow. It is believed that in cases such as this, slug and coolant temperatures may become critical. Present charging procedures allow for flow seating of the slug column. The distance the column is flow seated varied from very little to 3 or 4 inches depending on the particular charge. It is believed that this practice can lead to the situation observed in the laboratory tests. During the past two months, there has been …

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The feasibility of the Liquid Metal Fuel Reactor (LMFR) proposed by Brookhaven National Laboratory as a source of electric power was thoroughly investigated. The reference design is based on an LMFR using U dissolved in Bi as the fuel and a thorium bismuthide in Bi slurry as the blanket. Detailed estimates of power costs are presented for electrical power stations from 226 to 904 Mw net electrical capability. (C.W.H.)

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The requirements of an atmosphere for the brazing of Al bronze to Inconel were considered on a thermodynamic basis. It was demonstrated that brazing was not possible in a vacuum or inert gas and is improbable in dry H/sub 2/. Attempts to braze in dry H/sub 2/ prove unsuccessful as predicted, except at isolated spots where filler metal had been preplaced. Modification of the plastic binder for holding the filler metal so as to remove Oi and introduce halogen gave no improvement. Negative results were also obtained when solid halide or halogen was incorporated. Satisfactory brazing was achieved with various solid fiuxes. Consideration was given as to what must be the properties of such a flux so that it should not have deleterious affects in s ervice. (auth)

The existence of antiprotons has recently been demonstrated at the Berkeley Bevatron by a counter experiment. The antiprotons were found among the momentum-analyzed (1190 Mev/c) negative particles emitted by a copper target bombarded by 6.2-Bev protons. Concurrently with the counter experiment, stacks of nuclear emulsions were exposed in the beam adjusted to 1090 Mev/c negative particles in an experiment designed to observe the properties of antiprotons when coming to rest. This required a 132 g/cm2 copper absorber to slow down the antiprotons sufficiently to stop them in the emulsion stack. Only one antiproton was found in stacks in which seven were expected, assuming a geometric interaction cross section for antiprotons in copper. It has now been found that the cross section in copper is about twice geometric, which explains this low yield.

Using the 1.19-Bev/c antiproton beam recently discovered at the Berkeley Bevatron of the University of California, we have measured the attenuation cross section in beryllium and copper. These cross sections are compared to attenuation measurements made with the same geometry using positive protons of the same incident energy (497 MeV).

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Radiochemically determined mass-yield curves are given for the fission of U/sup 235/ and U/sup 238/ by l4.7-Mev neutrons. Symmetric and to a less extent, very asymmetric modes of fission are more probable at that energy than in thermal fission. Yields of four fission products from the fission of U/sup 235/ have been measured as a function of neutron energy in the range thermal to 14 Mev. The yields of eleven masses have been measured from the fission of Np/sup 237/ by degraded fission spectrum neutrons. The mass-yield curve is similar to that from the thermal fission of Pu/sup 239/ with a ratio of peak to valley yields of approximately 175. Relative yields of one peak fission product and four valley fission products have been determdned under the following conditions: fission of U/sup 235/ and Pu/sup 239/ with thermal neutrons; fission of U/sup 235/ Pu/sup 239/ and U/sup 238/ with fission spectrum neutrons; and fission of U//sup 235/ and Pu/sup 239/ with the intermediate neutron spectrum at the center of the Los Alamos Fast Reactor. Absolute yields of Moss have been determined from the fission of U/sup 235/,Pu/sup 239/ with thermal neutrons. (auth)

An event is described that is interpreted as evidence for the simultaneous production of a {theta}{sup 0} and a {bar {theta}}{sup 0} according to the scheme of Gell-Mann and Pais. This interpretation assumes the production of a normal {theta}{sup 0} and a K{sup 0} with no associated hyperon, where the {theta}{sup 0} is observed and the K{sup 0} is inferred from the rule of associated production of heavy unstable particles. The event was obtained by exposing a high-pressure diffusion cloud chamber to a 4. 5-Bev/c {pi}{sup -} meson beam from the Bevatron.

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Methods are described for metallographic preparation of binary U alloys having small percentages of Mo, Nb, or Si. Details are given of mounting, attack- polish technique, and electrolytic etching. Photornicrographs are shown of sintered specimens of U--Mo and U--Nb and of a cast specimen of U--Si. (auth)

Methods of melting uranium and its alloys are examined including vacuum induction melting and consumable and non-consumable electrode arc melting. The equipment and procedures are outlined with the limitations and uses of each method. In addition, the preparation and properties of Al--U, Cr-U, Mo--U, U-- Nb, U--Si, and U-Zr, and Nb--U--Zr alloys are described. Special techniques of agitation during freezing to produce fine castings are listed along with a discussion of the advantages of centrifugal casting. (J.R.D.)

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One equipment control building designed to be blast resistant and two each of three standardized types of metal warehouse or utility buildings were exposed to the effects of a nuclear device detonation. One of the utility buildings was frameless, with deeply corrugated wall and roof sections; a second was very largely frameless, utilizing interlocking channel sections; and in the third the aluininum-panel wall and roof covering was supported by girts and purlins, which in turn were supported by steel frames. Because of atmospheric conditions at the time of an earlier detonation in the test series, one of each of the three types of utility buildings was exposed to approximately 0.7 psi overpressure before the planned test. In the planned test one of each of the three types was exposed to approximately 3.0 psi overpressure and one to 1.3 psi, with the intention of bracketing their overpressure survival range and obtaining data for possible economic redesign for improved blast resistance. The equipment control building utilized continuous-welded steel frames and reinforced-gypsum curtain-wall construction. The control building was exposed to approximately 4.1 psi, in the anticipated fringe zone of major structural damage, to determine its protective capabilities. The blast-resistant equipment control building was …

The nuclear safety specifications (1) for handling J-slugs have previously been reviewed. These specifications provided information for the storage of loaded 100-hole shipping containers and loaded 66-hole wood cart pallets in certain arrays. Storage of J-slugs in J-Material Crates conforming to Drawing No. H-3-6217 had not been reviewed for the previous specifications. It has become desirable to provide specifications for J-slug storage in these crates as well as make additions to the present specifications on the storage of these enriched slugs in shipping containers and pallets. The results of this study pertaining to arrays of J-slugs in shipping containers and pallets will be incorporated as an addition to the present specifications for handling J-slugs.

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Results from studies of irradiation induced transformations in U--Mo and U--Nb alloys are reported. Progress in the development of a satisfactory brazing technique using Al alloy for use with U/sub 3/Si mods in Zircaloy-2 tubes is reviewed. Additional data are given on the corrosion of bare of U--q systems in water. Work directed toward the development of satisfactory UO/sub 2/ for fuel elements is reviewed. (D.E.B.)