The general requirements for the SNAP Reactor Cores include the fabrication of fuel elements. These elements consist nominally of 90 wt% zirconium-10 wt% highly enriched uranium (93% U/sup 235/) rods hydrided to an NH of 6.0-6.5 and machined. Alloying will be accomplished by triple arc melting. Forming will be done by extrusion, massive hydriding by techniques developed at Atomics International, and cladding by conventional means. (auth)

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The INOR-8 tube bundle of the primary heat exchanger of the Molten-Salt Reactor Experiment contains 163 1/2-in. dia. x 0.042-in.-wall U-tubes welded to a 1 1/2-in.-thick tube sheet, 17 in. in diameter. Procedures were successfully developed for welding and back brazing the closely spaced 326 tube-to-tube sheet joints in the unit. Trepan grooves were machined in the weld side of the tube sheet so that low-restraint edge-type welds could be made. The 82 Au18 Ni (wt%) brazing alloy used is corrosion resistant, ductile, and produces joints exhibiting satisfactory mechanical strength. A unique joint design incorporating a trepan groove and feeder holes was used for the braze side. Nondestructive inspection of the welds revealed no defects. Good general flow of the brazing alloy was evident, and ultrasonic examination of brazed joints showed only minor scattered porosity. The completed unit passed both heliumleak and 800-psi hydrostatic tests. (auth)

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Activities in a program to test and develop prototype fission-heated thermionic cells for space uses are reported. During the period, in-reactor tests were conducted on two W-clad U-bearing fuel emitters and one unclad type. Fuel emitter proof tests were also conducted which demonstrated 1000-hr operational capability of W-clad systems. Output power density and the temperature of heat rejection were found to have major effects on the weight- performance characteristics of the system. Advances in techniques related to W vapor deposition are reported. Descriptions of the fuel-emitter development, cell design and development, and testing of out-of-pile and in-pile cells are included. Operation of the clad-type test cells at design power and temperature led to selection of these cells for planned long-duration in-pile tests. (J.R.D.)

The wake produced by a Snap 10A reactor striking the water with its axis perpendicular to surface of the water was investigated. Based on tests performed on a similarly shaped missile, it is estimated that the cavity created by the nine-inch diameter, 175 pound reactor would exceed 22.9 in. in diameter and be greater than 17.9 ft in length before it collapsed; the reactor would be deeper than 17.9 ft and the cavity would extend to the surface. The duration of the cavity would exceed 233 msec. It is probable that the size and duration of the cavity resulting from the impact of the 16-inch diameter reactor would also exceed these dimensions. (auth)

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The Analytical Mass Spectrometry Section at Oak Ridge National Laboratory has, for many years, been determining relative isotopic abundances from solid samples. Thus, useful analytical mass spectrometer experience with every pertinent element has been obtained. These include the 55 polyisotopic elements as well as products of irradiation and fission. The techniques used are summarized in this report. A separate page for each element lists preferred compound, loading of sample, manner of obtaining a stable ion beam, and solutions of special problems. (auth)

A digitizer and data handling system that measures the locations of images on transparent film by automatically scanning an area with a mechanically generated flying spot of light is described. The location measurements are directiy transmitted for processing to a digital computer, which also controls the digitizer operations. A 4 in. x 5 in. negative can be scanned by a roster with a pitch of 50 mu in about 3 min. (D.C.W.)

ln the case of a linear-lumped control system with slowly changing performance characteristic, the process identification problem can be solved by evaluating, as functions of time, the coefficients of the polynomials that constitute the transfer function of the undetermined control system. A method of estimating these coefficients is described; and its advantages and limitations are discussed. The technique applies only to linear-lumped control systems whose zeros are known, and hence estimates only the poles of the system. The accuracy of the estimation in the presence of noise is discussed. In particular, techniques are evolved to enable choice of the fixed systems to lessen any error in the estimation due to noise. Expressions are evolved for error estimation with gaussian noise and signals. Techniques are also discussed that further lessen the errors in the estimations once the fixed systems have been chosen. Finally, a computer simulation of the estimation method is presented for a few simple cases. Conclusions drawn from the simulation indicate that the method does indeed measure the unknown parameter and yield good results for reasonable noise levels. The simulation also corroborates the error reduction techniques previously discussed. (auth)

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Separate abstracts were prepared for forty of the sixtytwo sections in the report. Three papers included were previously abstracted for NSA. (D.C.W.)

Development progress is reported on fast reactors, liquid metal cooled reactors, ZPR-III, ZPR-VI, ZPR-IX, Borax-V, Faret, EBR-I, EBR-II, Treat, Fermi Fast Breeder Reactor, critical assemblies, Argonne Fast Source Reactor, EBWR, Argonne Advanced Research Reactor, magnetohydrodynamic cells, fuel cells, and boiling water reactors. Reactor technology is reported on fuel development and properties, physics, heat engineering, materials development, chemical separations, nuclear safety, and nondestructive testing. (N.W.R.)

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Electron microfractography has been utilized to characterize the fracture modes of deformation of unalloyed alpha plutonium over the temperature range --196 to 100 deg C. It has been found that the fracture mode at -- 196 deg C is entirely by intercrystalline separation. At the higher temperatures the fracture mode is primarily by transgranular cleavage with some evidence of ductile shear. (auth)

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A simulator for studying fast reactor acciderts by use of an analog computer is described. A flux plot or temperature distribution analysis can be made using only a 5 x 5 mesh of an average channel in the core. The equations, circuitry, and operating instructions for duplicating an EBR-II-type accident are covered. Results from the simulator for a sample problem are compared with a digital computer solution. (auth)

Increasing industrial, military, and space requirements for certain fission products place emphasis on large-scale methods for their recovery from waste liquors produced by the fuel recovery processes. With development of organic extractants for separating and recovering these fission products, solvent extraction offers a versatile alternative to ion-exchange, precipitation, and crystallization procedures heretofore used for small-scale recoveries. A process flowsheet was developed for the recovery of strontium and mixed rare earths from adjusted Purex 1WW solution by the use of di(2-ethylhexyl)phosphoric acid (D2EHPA). After adding tartrate t complex the iron and caustic to adjust the pH to 6, strontium and rare earths are co-extracted and then co-stripped with nitric acid in the first cycle. In additional D2EHPA extraction cycles, they are isolated as concentrated fractions. The mixed rare earths from this process can be treated by tributyl phosphate (TBP) extraction to separate the individual rare earth elements of which promethium and cerium are of greatest interest. Zirconium--niobium also may be recovered with D2EHPA from acidic waste liquors. An amine pretreatment extraction process was developed for removing nitric acid, iron sulfate, zirconium-- niobium, and ruthenium from waste solutions to furnish a feed liquor more amenable to subsequent processes for recovering fission products. …

A fuel element hold-down device, which is an integral part of the fuel element assembly, was developed to lock reactor fuel to the bottom grid plate. Concurrently with the hold-down latch development, a fuel bandling machine grapple capable of setting, releasing, and checking the hold-down device was developed. (auth)

The development and operation of the Los Alamos Molten Plutonium Reactor Experiments are described. The development and compatibility of iron-- plutonium and cerium-cobalt-- plutonium alloy fuels are evaluated. The fabrication and testing of the liquid sodiam loop are summarized. The phase studies of plutoniam alloys containing neodymium, scandium, yttrium, praseodymium, and cerium-- cobalt mixtures are reported. (N.W.R.)