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A high expense item in the operation of the button line has been the RS-6 crucible which can be used only once. The 234-5 Research and Development Laboratory has done some preliminary development on a reusable crucible. Before continuing their program, they have requested that an economic study be made to determine what potential savings could be realized if RS-6 were replaced with a reusable crucible. For the purpose of this study, the costs involved were broken down into three areas: Button line costs, Recuplex costs, and Conversion costs. Button line costs include initial crucible costs, operational handling and radiation factors, and other material savings. Recuplex costs cover the effect the elimination of crucible fragments would have on the recovery operation. Conversion cost is an estimate of the expense required to convert the present button line to use a reusable crucible. The results of the study are very favorable and the total possible savings appear to be high enough to write off the cost of conversion of the button line to use the reusable crucible in one year. To write the conversion off in one year, the purchase cost per firing of the crucible must be equal to or less …

The interim design and development status is reported. The scope of the work was limited to conceptual design studies supported by critical experiments plus heat transfer and hydraulic tests. Design criteria, facility and site, reactor, core geometry and composition, fuel elements, reflector, core and reflector support structure, reactor vessel, control and instruments, primary coolant systems, secondary coolant system, auxiliary systems, experimental facilities, building layout and construction, plant ventilation, heating and air conditioning, critical experiments, reactor physics, heat transfer studies, and shieldings are discussed. (M.C.G.)

A function to evaluate the cost of electricity produced by a nuclear power reactor was developed. The basic equation, revenue = capital charges + profit + operating expenses, was expanded in terms of various cost parameters to enable analysis of multiregion nuclear reactors with uranium and/or plutonium for fuel. A corresponding IBM 704 computer program, which will compute either the price of electricity or the value of plutonium, is presented in detail. (auth)

The development of procedures for the vacuum induction casting of U--Mo alloys into both thin (0.010 to 0.100-in. thick) plates and long (36 in.) plates is described. Melting and casting cycles were developed, and casting techniques established, which resulted in sound, integral plates. These plates were evaluated by radiographic and metallographic examination, and by chemical analysis. The results indicated the feasibility of the process for the fabrication of fuel plates for nuclear reactors. The process promises a potential reduction in fabrication costs, by eliminating waste. (auth)

Forty-nine hydrocarbon products were evaluated in the laboratory in a search for a highly stable diluent for the organic extractant used in a radiochemical separations plant. The formation of zirconium ligands during chemical and radiolytic degradation increased with boiling point for isoparaffinic producte but was approximately constant for n-parafiins. Of those materials that met the local flash point specification, the n-parafiins were superior. (auth)

The present knowledge of the shielding constants of concrete is summarized. The densities, elemental compositions, and mixes, where available, are given for a wide range of concretes. From these data, various constants useful for shielding calculations were computed. These constants include the removal cross sections, total cross sections, average thermal neutron absorption cross sections, thermal neutron diffusion coefficients, reciprocal thermal neutron diffusion lengths, total gamma-ray linear attenuation coefficients, gamma-ray energy absorption linear attenuation coefficients, the effective atomic numbers for the determination of buildup factors, and the capture gamma-ray spectra. Experimental results are included where available. (auth)

A process scheme for the recovery of uranium from fuel elements has been developed. The scheme combines continuous fluid-bed drying and fluoride volatility techniques after initial dissolution of the fuel element in the appropriate aqueous system, hence the designation ADF, Aqueous Dry Fluorination Process. The application of this process to the recovery of uranium from highly enriched, low uranium-zirconium alloy plate-type fuels is described. ln the process, the feed solution is sprayed horizontally through a two-fluid nozzle and is atomized directly in the heated fluidized bed. The spray droplets are dried on the fluidized particles and form a dense coating. Excessive particle growth was limited by the use of air attrition-jets inserted directly in the bed. Aqueous hydrofluoric acid solutions containing l.2 to 3.6 M zirconiuni, 0.007 to 0.03 M uranium, and free acid concentrations from 1 to about l0 M were successfully processed in a 6-in.-diameter Inconel fluid-bed spray dryer. Rates equivalent to about 3.l kg/hr of zirconium were achieved, 160 ml/min with the most concentrated feed solution. Experiments were successfully carried out from 240 to 450 deg C. A new design for a two-fluid nozzle was developed. Extensive work was done to identify the various zirconium fluoride compounds …

An arc furnace is described which employs a nonconsumable tungsten electrode and a water-cooled copper hearth. It is used successfully for melting refractory metals and alloys. The furnace is equipped with a vacuum system, an inert gas supply, and an 800-ampere directcurrent power supply. (auth)

A large ultrahigh vacuum chamber was built for environmental testing of components for the SNAP program at temperatures as high as 1000 deg F. The chamber employs diffusion, electronic, and cryogenic pumping to handle high gas loads at high temperature and ultrahigh vacuum. A unique internal heating system, connections, assemblies, flanges, and test set-up jigs are described in detail. (auth)

A method is presented for translating inspection measurements of fuel plate spacing to obtain minimum coolant channel clearances under reactor operating conditions. Considerations of fuel plate ripple growth and the inspection procedure used are included. The method is applied to establish dimensional tolerance specifications used for the procurement of SM-1A and PM-2A Core II. (auth)

GAMMA I is a FORTRAN-compiled program for the IBM 704 Electronic Data- Processing Machine. It embodies a certain general, uniform procedure H of mathematical logic for seeking out a proof of any theorem within any mathematical theory which is given in formal axiomatic form. An extended discussion is provided of the underlying method and of the necessary background of mathematical logic. The program is described in detail. (M.C.G.)

An investigation was made to determine the effect of rolling temperature, roll pass design, amount of reduction, and heat treatment before and after rolling on the anisotropic growth rate of uranium under irradiation. The growth rate was found to increase with decreasing rolling temperature and with increasing reduction of area at 300 deg C. The rate of elongation was proportional to the amount of (0l0) component present or, where shortening occurred, to the amount of (l00) component. Oval-edgeoval roll passes resulted in somewhat higher irradiation growth rates than did round roll passes. Recrystallization after rolling effectively reduced the irradiation growth rate of uranium rolled at temperatures of 500 deg C and lower. Irradiation caused length shortening in uranium which was beta quenched after being round-rolled at temperatures of 400 deg C and above, and which was beta quenched after being oval- rolled at temperatures of 300 deg C and above. (auth)

>An assembly was constructed which simulated the moderator coolant annulus in the Experimental Gas-Cooled Reactor. This assembly was preheated to various temperatures and air was passed through the coolant annulus. Under certain conditions it was demonstrated that self-sustained combustion of the graphite could occur. Rates of temperature rise were generally less than 1 deg C/ min until the graphite temperature exceeded 700 deg C and then rise rates became very high. In these cxperimcnts, the assembly was not operated in such a manner as to give ignition temperatures eharaeteristic of the EGCR. These tests were designed only to investigate the effects of changing such parameters as the rate of coolant flow, air humidity, prior oxidation on the graphite, and air inlet temperature. A later series of experiments to more closely duplicate the EGCR operating conditions was completed and will be reported in a second report, HW- 71182. (auth)

Existing experimental data on the variation of reactivity with core geometry are reviewed. Four typical fast neutron systems are analyzed to predict: (l) the variation of critical mass with cylindrical core geometry (core and reflector composition are held fixed); (2) the reactivity worth of fuel at the radial core boundary as a function of cylindrical core geometry; and (3) the geometric variation of heat removal parameters; these include the ratio of: (a) Maximum power density to average power density in the core. (b) Maximum power density to average radial power density in the core. (c) Total reflector power to total core power. The absolute values of all of these parameters are determined by the core and reflector compositions of the four systems. These were chosen to simulate typical constituents of interest to reactor analysis. Two systems represent a typical fast reactor and a typical fast critical experiment. The other two systems represent compositional combinations of the two basic systems. The results of the analyses show that the significant geometric varia tion is in items (2) and (3b). Itenm (1) is almost constant for small variations near the optimum geometric configuration. Outside of this range, the variation of critical mass with …

In laboratory studies the dissolution of iron in dilute nitric - hydrochloric acid mixtures shows an apparent reaction order of -0.62 with respect to HCl. No apparent order value for HNO/sub 3/ can be determined over the concentration ranges studied. Nickel dissolutions show apparent orders of 1.4 with respect to the HCl and 4.2 for HNO/sub 3/. Activation energies determined from 50 to 80 deg C are not constant, ranging from l0 to 20 kcal per mole for both metals. (arth)

BS> The use of titanium getter pumping for large vacuum systems is described. Techniques were developed which give sorption rates approaching the maximum theoretically possible for many of the chemically active gases. A simple method of determining sticking fractions is descrnkbed. Sticking fractions for hydrogen, deuterium, oxygen, nitrogen, carbon nknonoxnkde, carbon dioxide, and methane are given for various films. The capacity and sorption characteristics for these films are shown. Simple and reliable resistance-heated titanium evapdorators are described. lt was demonstrated that the pumping methods described provide outstanding performance and are both reliable and practical. (auth)

At the end of September l961, construction of the Heavy Water Components Test Reactor was about 90% complete. Thirty-two compacted tubes of crushed, fused uranium oxide in Zircaloy sheaths were fabricated for irradiation tests and destructive evaluation. lrradiation tests of the tubes were started in the Vallecitos Boiling Water Reactor and at Savannah River. The fabrication process for the tubes included steps designed to exclude hydrogenous material from the oxide cores, thereby eliminating the probable cause of sheath failures in previous irradiations. Additional experimental data on heat transfer burnout of tubes in subcooled water at pressures of about 100 to 1000 psi showed that the burnout heat flux is not affected significantiy by pressure in this range. The data were correlated in terms of water velocity and subcooling. (auth)

Some of the factors affecting the counting rate achieved by a neutron chopper spectrometer are investigated. It is shown that in a chopper of optimum design the counting rate per channel at any given energy is proportional both to the slit width and to the square of the resolution in mu sec/m, as well as to the cutoff velocity vc of the rotor; this last is because a larger number of bursts per second become possible as vc is increased. For an idealized cutoff function, it is shown that the total running time for measuring a spectrum is minimum when the ratio of cutoff velocity to peripheral velocity of the rotor is such that approximately 1.67 runs per energy decade are required; this means that the chopper speed and the time-channel width are changed by a factor of two from one run to the next. (auth)

An investigation is reported of the effect of several oxide additives on the densification of UO/sub 2/-ThO/sub 2/ compositions in which U/sub 3/O/sub 6/ is the initial uranium oxide. Also determined were the effects on densification of variation of the compaction pressure and of the pretreatment of the oxide powders. The validity of results was checked by two forming techniques, dry pressing and extrusion. The results are indicated as follows: additives had an increasing effect on densification with decreasing ThO/sub 2/ content; oxides of transition elements were most effective as additives for im i proving the densification; varying the forming pressure had little effect on densification; precalcination of the initial powders was effective in improving densification; and similar results as above can be achieved with extruded as well as dry-pressed specimens. (auth)

The computer codes CROCK and SHOCK, written to aid power system designers in selecting the minimum weight point for space power plant radiators, are described. CROCK can be used to select the minimum weight design for a system in which the waste cycle heat is radiated directly to space from the condenser, while SHOCK can be used for systems in which the sensible heat lost from a single-phase fluid is radiated. (J.R.D.)

Analogy with optical instruments is used to develop formulas for estimating the counting rate achieved by a neutron time-of-flight system. lnput data consist of the flux at the spectrometer entrance and some of the physical characteristics of the spectrometer. Convenient relations for the comparison of different systems are presented. (auth)

A study was initiated to determine the precision with which surface temperature measurements could be made in irradiation capsules containing ceramic fuel. A thermocouple was considered to be positioned in a longitudinal groove prepared in the uranium oxide and metallurgically bonded to the inside surface of the stainless steel clad. A fuel capsule having a 3/4 inch outside diameter, designed as a segment of the EGCR fuel element, and operating with a heat generation rating of 27,500 Btu/hr/lineal foot was assumed. The finite difference approximation was employed to study both the grounded and the ungrounded types of thermocouple junctions. It was found that when a short dummy lead is positioned axially adjacent to the thermocouple junction deviations of about 118 deg F and 101 deg F are obtained for the grounded and ungrounded junction, respectively; in both cases the indicated temperatures are in excess of the undisturbed clad surface temperatures. (auth)

The addition of alloying elements to base alloys of Th containing 5 and 10 wt% U was investigated with regard to alloy structures and elevated- temperature mechanical properties. The alloys developed possess elevatedtemperature tensile and stress-rupture strengths of essentially twice those associated with binary Th-5 and 10 wt% U alloys at 60O to 800 deg C. The greater strength of these alloys should resuit in improved resistance to radiationinduced swelling at high temperatures. Noticeable improvement in elevated-temperature mechanical properties resulted from the addition of 2 and 5 wt% Zr to the Th-5 and Th-10 wt% U base alloys. Zr was found to be the most effective additive in improving elevated-temperature mechanical properties, although significant improvement was noted with additions of Nb, Mo, C, Al, and Be. Both solidsolution strengthening and dispersion strengthening of the Th --U base alloys were encountered. It was found that a fine intragranular distribution of the secondary U phase improved the mechanical properties of the alloys studied. Structures with optimum properties were produced by careful control of the arc-melting procedure and by solution heat treating at 1350 deg C followed by aging at 850 deg C. Preliminary testing was performed to determine the elevatedtemperature mechanical properties …