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 percentage of helium which will bypass the core if the reflector system shown is used is predicted. It is estimated that nominally about 0.1 to 0.2% of the total flow will bypass the core, which is not considered excessive. The most difficult parameter to determine was Z, the gap between the sealing surfaces. The method used to predict Z is presented. The effect of bowing due to a temperature gradient across the seals is discussed. (auth)

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 bibliography on pion-pion interactions is presented. The 241 references are those available through November 7, 1961. A chronological listing is given together with excerpts or comments. In another part the references are grouped according to subject. An author index is included. (M.C.G.)

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)

The growth of nonprotective, crust-like oxide films was encountered in high-temperature alloy systems that contain molybdenum, vanadium, or tungsten as strengthening additions. The cause of accelerated oxidation in such alloys appears to be associated with the characteristically low melting temperatures of oxides of these refractory elements. The factors that contribute to a breakdown of oxidation protection in these systems are outlined and remedial methods which may be used to avoid catastrophic oxidation are discussed. Commonly encountered service failures that have resulted from catastrophic oxidation are also described. (auth)

The Idaho Chemical Processing Plant did not operate on fuel recovery during this period, due to extensive renovation and modiflcation of facilities. Potasslum fluoride was found to be an undesirable additive to the barium precipitating agent used in formation of barium fluozirconate, because of precipitation and loss of uranium, although essentially complete precipitation of zirconium was achieved. Addition of hydrofluoric acid with barium precipitant, to achieve a fluoride/zirconium mole ratio of 5.5, was found to give a total zirconium recovery of 05%, including approximately 10% recovered after concentration of the supernate from the original precipitation. Removal of 97% of the zirconium and fluoride from zirconium -uranium dissolver solutions was achieved by precipitation with two moles of sodium formate per mole of zirconium. Uranium was readily recovered from the concentrated filtrate and wash solution by TBP extraction. The preparation and characterization of zirconium nitrate dibutylphosphate are described, and the solubility in Amsco was found to be similar to that of the uranlum dibutylphosphate complex (2 to 4 x 10/sup -5/ M). Stability studies indicated very little, if any, oxidation of ferrous to ferric iron ln a normal raffinate environment, and ferrous iron has a very low molar extinction coefficsent (0.8) compared …

A conceptual design and economic evaluation of 300 and 40 MW/.sub e/ steam-cooled fast breeder reactor power plants were performed. A reactor core composed of U-Pu oxide rod-type fuel elements clad with Inconel-X and surrounded by a blanket of depleted UO/sub 2/ fuel was studied in some detail. Reactor breeding ratios of from 1.27 to 1.5 and overall system doubling times of from 20 to 30 years are achievable. For the near term (1967) 300 MW/sub e/ plant, an energy cost of 7.6 mills/kwh is estimated, based on AEC ground rules for privately financed plants and utilities. This cost may go down to 5.7 mills/kwh by 1975. For the 40 MW/sub e/ plant corresponding energy costs are 19.5 and 13.7 mills/kwh, r -spectively. The R&D program required for this reactor concept is estimated at million with an additional million for improvements leading to the 1975 reactor. Investigation of the operational and safety aspects of the reactor indicated that satisfactory procedures can be used for startup, shutdown, and emergency cooling of the reactor. An increase in reactivity upon flooding can be prevented by incorprating small amounts of high resonance absorption material in the core. Preliminary calculations indicate a substantial increase in …

Studies carried out on corrosion associated with the hydrofluorination- dissolution phase in the fused-salt Fluoride Volatility Process are summarized. Corrosion for hydrofluorination-dissolver vessels used in bench-scale and semiworks-scale process development at ORNL is discussed. The results of a study on construction materials for the dissolution phase are presented. Corrosion studies at ANL are described for comparison purposes. A full-size hydrofluorinator dissolver is described. (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 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.)

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)

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 …

Under the influence of radiation, the coolant-moderator in an organic moderated reactor slowly decomposes to form high molecular weight polymers (high boilers) and a mixture of gases and light hydrocarbons as waste products. Work carried out on the improvement and subsequent operation of a prototype waste- polymer combustion process is described. Operation of the improved unit employing a vortex'' burner confirmed the feasibility of combustion as a disposal method. It was determined that fuel temperatures of 400 deg F and combustion air temperatures of 300 deg F were required for successful operation. The quantity of ash resulting from the combustion was established to be less than 0.5 wt% of the original polymer. It was determined that the efficiency of the primary dust collector varied from approximately 90 to 99%, and that there was no detectable particulate matter in the gas leaving the absolute filter. Attempted activity-balance calculations proved unsuccessful due to extreme difficulties in measurement of the low-level activty of the stack gas. In an effort to further improve and simplify the process system, preliminary evaluation of another burner was carried out. A cost estimate of the combustion process using the Vortex'' burner was prepared, based on data obtained from …

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)

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 …

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)

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)

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)

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)

Preliminary design concepts are presented for a wire scanner for experimentally evaluating spatial variations of neutron flux in the SM-l reactor core. Results of a literature search and determination of optimum criteria for flux mapping the core in minimum time dictated requirements for design concepts and specifications. The utility of both manually instrumented and automatically instrumented wire scanners was analyzed with respect to rapidity of measurement, selectivity of detector location, cost, value of data, plant downtime, and additional factors. (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)

Structural evaluations of the upper head of the EGCR pressure vessel were made. The configuration throughout the cluster region in the vessel was found to be structurally adequate. The primary and primary-plus-secondary stress intensities for the burst-slug detection and gas outlet nozzles were found to be within the allowable limits. However, the complete design evaluations of these units cannot be made until the temperature distributions are known. (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 …