Equations based on kinetic theory relate the contamination of refractory metals in vacuum to the appropriate variables. Several examples are given for which the allowable system pressures are calculated. The examples illustrate the effect of varying several parameters. The importance of the sticking factor for active gases on hot refractory metals and its effect on the system design are discussed. The data for estimating the sticking factor for O/sub 2/ on Nb are given, along with some estimated values. Experimental data on the composition and rates of outgassing of ultrahigh-vacuum systems and their importance in system design are discussed. Several methods of reducing contamination rates and the relative ease and effectiveness of these methods are presented. It was concluded that tests of 1000 hr or longer will probably require system pressures of between 10/sup -9/ and 10/sup -6/ torr, the particular pressure depending upon the residual gas composition, test duration, allowable contamination level, and the other variables discussed. Since the most important source of contamination in a properly designed ultrahigh-vacuum system is the outgassing process, bakeable systems should be designed to operate with walls as cool as practical, and to have a minimum of surface area and outgassing materials inside. …

The study of the mechanism of free-radical formation and decay in polymeric materials was continued and extended to include an investigation of the potential application of this information to the development of novel graft copolymers. The study of postirradiation grafting techniques employing both peroxide initiation and direct grafting was continued. In addition, the effect of molecular weight on site formation was further investigated. Licenses and license applications for approximately 300 by-product material licenses were reviewed to obtain information on environmental conditions of source usage. The feasibility of testing sealed-source response to normal environments by accelerated test procedures was studied. Indications are that the approach will probably not be applicable to either vibration or abrasion stresses but may be for corrosion stresses. (auth)

The results of Spert I in-pile transient tests of a rodtype, low- enrichment UO/sub 2/ fuel element are presented. The tests were performed to investigate the possibility of damage to such long thermal-time-constant fuel rods when subjected to short-period power excursions, and to test the effectiveness of an instrumentation technique for measurement of UO/sub 2/ fuel temperatures within the rods. In an initial series of power excursion tests, in which the range of reactor periods was from approximately 1 sec to 7.5 msec, simultaneous measurements were made of the transient temperature at the center of the fuel rod and at the outer cladding surface. Fuel rod rupture occurred during the exponential rise of the 7.5-msec excursion. Similar short-period tests performed on a second fuel rod contain ing no internal thermocouples did not result in cladding failure, supporting the postulation that rupture of the first rod was caused by waterlogging of the UO/sub 2/ as a result of the cladding penetrations made for installation of the internal thermocouples. Calculations of the transient temperature distribution in the fuel rod were made, and the results are found to be in good agreement with the experimental data obtained on the central-UO/sub 2/ and cladding-surface …

The experimental plan for irradiating BeO pellets in Experiments ORNL 41- 8 and ORNL 41-9 was chosen in accordance with the principles of experimental design. The design is known by statisticians as a 2/sup 5/ factorial experiment confound'' in six replications. Five variables---size, density, grain size, temperature and time--are controlled at two levels to form the basic 2i factorial experiment. The sixth variable, neutron flux, is introduced by confounding on higher-order interactions. An explanation is presented in nontechnical language the means by which the aims of the experimenters and the physical conditions affecting the experiment were utilized in constructing the experimental design. (auth)

Continued research is reported in the areas of intrinsic radioactive tracers for industrial process control and the effects of structural factors on radioinduced graft polymerization. The use of Be-- Po neutron sources for production of short-lived isotopes is being investigated. Data are included on the effects of target volume, high-Z scattering media, target-isotope concentration, and macroscopic cross-section on speciflc and total activation produced with a 10-curie source. Research on graft-polyerization concerning the effects of structure on freetinued. Results indicate that the radical formed in a variety of substituted methacrylate polymers is the same in all cases. (J.R.D.)

A summary of the progress on development of the ALGOL compiler for the Control Data Corporation 1604 Computer is presented. This computer is based on machine-independent specifications developed at ORNL. A brief description of the structure of the compiler is included along with discussions concerning language restrictions, the hardware language representation, and the required equipment configuration. An example illustrates the generated program instructions. (auth)

The utilization of physical and chemical processes to reduce the rate of vapor loss of thermionic emitters composed of mixed carbides of U and Zr in order to increase the permissible operating temperature is being studied. Preliminary, qualitative results obtained from study of physical redeposition processes showed that increasing the collector temperature may markedly reduce the rate of weight loss from a UC emitter operating at 2053 deg K. The requisite experimental equipment for studies of chemical transport processes was designed and constructed. Experiments will proceed through both a physical chemistry approach to an understanding of the transport processes and a technique to evaluate the efficacy of possible combinations of chemical species by monitoring the electron emission from diodes containing such mixtures. (auth)

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Tests were conducted to determine whether a time limitation exists on the use of internally water-cooled hollow copper conductors operating at densities of up to 330,000 amps/in/sup 2/. Using demineralized water, having a specific resistivity of 4 to 9 x 10/sup 6/ ohm-cm, no indication of a decrease in heat transfer coefficient as a function of time was observed. However, metallographic examination revealed that corrosion--erosion does occur at a slow rate. Using process water there was a time dependent decrease in heat transfer coefficient and a consequent rise in metal temperature. The subsequent use of demineralized water in the same conductor again produced stable heat transfer, over the time spans investigated, 192 hours. The maximum total time investigated was 873 hours for one conductor. (auth)

Calculations are made to determine the safe steadystate power operating limits of the Spert III reactor from the viewpoint of fuel plate burnout. A computer program is developed for the IBM 704 to aid in these calculations. The Bettis design departure from nucleate boiling (DNB) equation is used in conjunction with the LeTourneau and Grimble method of hot channel'' analysis in the development of the calculations. For cases where DNB occurs in the bulk boiling region, a modified Martinelli-Nelson twophase flow correlation and some experimental singlephase pressure drop data are employed. DNB for a typical operating condition of 550 deg F inlet temperature and 2500 psig is computed to check the code. The results of the sample calculation show that at a steady- state power level of 60 Mw (maximum design power) the minimum flow rate required to prevent DNB is approximately 8000 gpm. (auth)

This test is identical to the original except that it authorizes the performance of a trial reduction in reactor flow during a prior reactor shutdown. This trial flow reduction will be performed in the same manner as proposed for the actual test, with one exception. This is, that based upon the results of this preliminary test some changes in the timing of the different steps may be indicated. Such changes can readily be handled by making each step dependent upon the observed reactor outlet temperature during the test performance. The other significant change in the production test is the increase in the allowable bulk outlet temperature from Ti + 40 {plus_minus} 3{degrees}C{sup *}. This change is needed to obtain a reasonable extrapolation of the results of tests No. 1 and No.2 to 90{degrees}C, and is justified from a hazards standpoint by the excellent flow control achieved during test No. 1 and by the trial test that will be run prior to the performance of the actual test No. 2. Other aspects of the test basis and justification are presented in the original production test.

We are enclosing three copies of a proposal concerned with the preparation for preliminary evaluation of up to 128 Hanford CV size I and II fuel elements to determine an optimum gas-pressure-bonding cycle for the fabrication of this type of fuel element. This proposal is based on your request as outlined in your letter dated May 7, 1962, and document No. HW-72417. Included is a cost estimate of the funding required to conduct this experimental study. All of the aluminum-clad uranium fuel assemblies are to be prepared and furnished by HAPO for gas-pressure bonding at Battelle in existing equipment. To implement the proposed program we have also enclosed six copies of the BMI-AEC research agreement (Serial No. 88). The agreement provides for a six-month research period with an estimated total cost of $24,780. This sum includes $1,180 find fee as established in Contract No. W-7405-ENG-92. Receipt of two fully amounted copies of the agreement, classification guidance, and the specimens will allow us to proceed.

This document summarizes the results of all special separations made in conjunction with the two E-N core loadings and the single fringe blanket loading irradiated in the H Reactor during 1961 and 1962. Tritium yields obtained at Savannah River from the N target elements have been reported previously. Bulk plutonium yield observations obtained from separation of the E-metal fuel elements in the first core and data from a limited number of small-scale separations were included in a comprehensive interim report. In addition to the above data a detailed sampling program was carried out as a part of the production test, and 18 representative 6--8 tube batches from the B-N core and from the surrounding blanket have recently been separated and analyzed. This document includes this recent information in its treatment of all E-N conversion ratio data from loadings under PT IP-350-C.

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Possible experiments that could be performed at the Brookhaven alternating gradient synchrotron using highenergy deuterons and heavier nuclei are reviewed. Particular attention is given to production of high-energy neutrons by stripping. A brief analysis of changes needed to accelerate heavier nuclei reveals such modifications would not be prohibitive. (D.C.W.)

The costs of shipping caleined Purex and Thorex wastes were calculated assuming the wastes were produced by a plant processing 1500 metric tons/year of U converter fuel at a burnup of 10,000 Mwd ton, 270 metric tons/year of Th converter fuel at 20,000 Mwd/ton. Calculations were made for Purex waste calcined in acidic and reacidified (after alkaline storage) forms and for Thorex waste calcined in acidic and reacidified forms and with constituents added for producing an acidic Thorex glass. Shipping casks of Fe, Pb, and U were considered at 25, 0.75, and 00/ lb. Casks were cylindrical in shape and up to 60 in. ID, which is large enough to contain four 24-in.-dia., nine 12in.- dia., or thirty six 6-in.-dia. cylinders of calcined waste. Cask weights ranged up to 100 tons. The cask design did not include liquid coolants or mechanical cooling equipment, and couriers were assumed not required. Minimum waste age prior to shipping because of temperature limitations ranged up to 11 years for acidic Purex with four 24-in.-dia. cylinders/cask. Rail freight rates of , , and /ton were assumed for distances of turn of the empty casks. Total costs were lowest in all cases for lead casks, and …

A time-to-height conversion system was developed which is useful for measuring time intervals from 10 psec to 200 mu sec. When driven by a mercury- relay pulse generator through appropriate fixed delays, the resolution of the system, FWHM, is 6 psec, the apparent time shift with temperature is less than 2 psec/ deg C, and the integral linearity is within plus or minus 1%. The apparent time distribution through a type 58 AVP photomultiplier tube driven by a mercury-relay pulser was less than 0.3 nsec at a fixed light level equivalent to 10/sup 3/ photoelectrons per pulse. The apparent time shift was less than 0.5 nsec for variations from 10/sup 2/ to 10/sup 4/ photoelectons per pulse. (auth)

Declassified 29 Aug 1973. Critical experiments were performed with fuel elements for the Project Rover KIWI-B-2A reactor to determine nuclearly safe conditions for their production, storage, and transportation. Each element is a 0.746-in.-dia and 50.5-in.-long uranium carbidegraphite cylinder containing seven uniformly spaced longitudinal holes. The uranium concentration is 400 mg/cm/sup 3/, of which 93.15% is /sup 235/U, yielding a C: /sup 235/U atomic ratio of about 90. Throughout the experiments each element was encased in a sealed aluminum tube. In order to establish both the minimum critical number of watermoderated and -reflected elements and the relationship between moderation and critical number, several critical arrays covering a wide range of moderation were assembled. lt was found that the minimum critical number of 66 elements, containirg about 5 kg of /sup 235/U occurred at an H: /sup 235/U atomic ratio of 380. The critical number of unmoderated elements in a reflected array was greater than 2500. Experiments were also performed with uranium oxidegraphite elements from an early stage of production. The minimum critical number of full- length elements in a moderated and reflected array was 40, containing about 4.6 kg of /sup 235/U. The H: /sup 235/U atomic ratio was 270. Several …

Exploratory and optimization experiments in the use of in-process isotope neutron sources to produce short-lived intrinsic radiotracers were initiated. Flux determinations using manganese sulfate solutions and indium foils were performed. The maxtmum thermal-neutron flux measured by indium acttvation was found to be 9.6 x 10/sup 4/ n/(cmsup 2/) (sec) for a 10-curie polonium-beryllium source. The peak flux occurred 3.2 cm from the center of the source through approximately 1.6 cm of water moderator. The study of the mechanism of formation of free radicals in polymeric materials was continued. Again, emphasis was placed on an examination of the effects of structure and molecular weight on the efficiency of free-radical formation in acrylate and methacrylate polymers. In addition, the investtgation of tbe potential application of this information to thc development of graft copolymers was continued. (auth)

The effects of various parameters on the transport propenties of dissociating gaseous mixtures were studied. In order to take advantage of the increase in thermal conductivity and specific heat due to the dissociation, the heat of dissociation must be large,'' the molecular weight and molecular volume must be small, and both associated and dissociated molecules must be present in appreciable amounts at reasonable temperatures. Very few dissociation reactions meet all of these requirements. In order to illustrate the effects of dissociation on many properties, estimates were made for the thermal conductivity, specific heat, specific volume, and viscosity of helium-- aluminum chloride and helium--fluorine mixtures as a function of temperature at various pressures and compositions. The maxima in the thermal conductivity and specific heat curves, which are due to the heat of dissociation, can be varied over a wide range of temperatures by controlling the pressure and helium concertration. The dissociation produces a greater than linear increase in specific volume with increasing temperature. According to the calculations, a helium-- fluorine mixture has a thermal conductivity and specific heat which can be as much as a factor of two greater than the corresponding values for pure helium, while the viscosity of the …

Most existing electron synchrotrons use betatron start for initial acceleration of the particles. The subsequent synchrotron acceleration is then performed with a nearly constant radio-frequency. Investigation of the effect of turn-on rate and initial energy spread is made mathematically. Several advantages are seen for such a technique. (D.C.W.)

Thin metallic foils were irradiated with a 15 microampere beam of electrons from an accelerator operating between 50 to 115 kev. The light emission spectrum from the foils was analyzed with a Seya-Namioka Vacuum UV Monochromator with an EMl 6256B photomultiplier tube as detector. The metals irradiated with silver, aluminum, and gold with the former being unbacked and the latter two supported on thin organic substrates. The silver and aluminum data were compared with previously derived theories for the emission of radiation from a dielectric. Substantial agreement was found between theory and the measurements. (auth)

A program (ZORCH) is described which is an extended and revised version of the point-model kinetics program MURGATROYD. A model is used in which the axial space dependence of the fuel and graphite temperatures is calculated, and the effect on reactivity of deviations from the steady state values is assumed to be given by the product of an appropriate temperature coefficient of reactivity times the deviations from the steady state value of the nuclear average temperature (NAT). The NAT is computed using a sine-squared'' weighting function in the axial direction and using an input weighting factor in the radial direction. The shape of the power density is taken to be - time- independent in contrast to the shapes of the temperature distributions, which are time-dependent in the calculation. This program is intended to be used in surveys of reactor behavior under a wide range of conditions. It is therefore based on a simplified model in order to reduce computing time, but should provide a better approximation to reactor behavior than does a purely space-independent calculation. A derivation of the equations used in the program, instructions for its use, and sample input and output for a test case are included. A …

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