The A-DFR is based on the use of a fissionable dust carried in a gas. This fuel ferm offers promise of a major economic advance through the use of 2,000 to 3,000 F operating temperatures and a low cost fuel cycle. The development program is described that was initiated to investigate experimentally the proposed fuel and study analytically other reactor characteristics. A brief review of the reactor concept is presented. (W.D.M.)

Originally intended for publication as NNES-VIII-7. Elghty-one papers are presented on thc chemistry of uranium. (W.L.H.) 13236(Abstract unscannable)

Many types of measurement systems were reviewed for appropriateness of the task of continuous uranium monitoring of a liquid-metal fuel reactor. Of these, the three general classes of neutron methods, x-ray methodss and paramagnetic suseeptibility methods were selected for detailed evaluations primarily for the case of liquid-fuel stream monitoring. In additions the present state of development of electrochemical and spectroscopic methods for application to fused-salt monitoring was assessed. There is no feasible method based on neutron detection that could be made insensitive to fission products in the liquid fuel stream. Methods employing the expected delayed neutron flux as a neutron source show promise of feasibility. Of the several possible methods based on neutron attentuation, one shows promise of feasibility. A method based on irradiation of fuel solution with thermal neutrons and detection of fast neutrons of fission origin appears to have at least marginal feasibility. Liquid fuel monitoring based on x-ray absorption measurement is at best marginally feasible. The spectrum of fission product photons emerging from U-Bi solution may be expected to show structures due to quantum interactions with the constituents of the solutions that might prove applicable to uranium analysis. We recommend that this spectrum be investigated experimentally. Of …

The design of the S3G and S4G reactor pressure vessel heads led to a study of perforated plates. A correlation of perforated plate theory with experimental data is given. The test results and analysis used for the S3G model tests are presented along with a review of two other experimental programs in which the experimental data were correlated theory. The conclusions reached indicate that the perforated lattice does, in fact, behave as an equivalent plate of reduced stiffness when subjected to transverse loading. The results obtained from the theory are sufficiently accarate for engineering applications for a range of plate sizes which extends from thin plates (radius-to-thickness ratio 7.5 to 1 for Duncan's tube sheets) to thick plates (radius-to-thickness ratio 1.6 to 1 for the reactor model head) with a variation in the number of penetrations ranging from the large number in Duncan's tube sheet tests down to the relatively small number (19 holes) ia the reactor model head (3/8 scale model). (auth)

None

The basic design and development concepts are presented on a six vane air motor intended for use at elevated temperatures. (auth)

The oxidation of ferrous sulfate is used as the method of measurement of radiation intensity in the Argonne National Laboratory's High-Level-Gamma Food Irradiation Facility. The preparation and calibration of the dosimeters are described and illustrated photcgraphically. (C.H.)

Irradiations were made on a number of uranium-plutonium alloy specimens made from both cast and extruded materials. The cast alloys included alloys of uranium with 3.7, 5.6, and 13.0 wt. % plutonium, and the extruded alloys included alloys of uranium with 9.5, 14.1, and 15.7 wt.% plutonium. One-half of the extruded specimens were given a heat treatment consisting of heating to 545 deg C and cooling to and holding at 500 deg C for one hour in an attempt to remove the preferred orientation that was anticipated from extrusion. The specimens were irradiated to burnups ranging up to 0.54 at. % with central temperatures ranging up to 490 deg C. The cast specimens were all found to have developed severe surface roughening as a result of the irradiation they received, presumably because of excessively large grain sizes present before irradiation. Identically fabricated unalloyed uranium specimens showed similar behavior. The as-extruded alloy specimens maintained good surface smoothness under irradiation, but showed elongations which were dependent on plutonium content. For example, in samples with 0.4 at.% burnup, a 14.1 wt.% plutonium alloy specimen elongated 96%, whereas an 18.7 wt. % plutonium alloy specimen elongated only 5.4%. The heat-treated extruded specimens did not …

Concentrations of radioactivity in several types of samples obtained from the ANL site and from locations approximately 10, 25, and 100 miles from the Laboratory are given. Since ANL waste water is discharged into Sawmill Creek, which in turn empties into the Des Plaines River, special emphasis was placed on sampling these streams. Most of the results were obtained by coumting the total alpha and beta activities after suitable preparation of the samples. Some of the samples were also analyzed for specific elements and nuclides. The average total activities in water, bottom silt, surface soil, and plants during 1956 are shown. The average activities in these types of samples from 1952 through 1956 are compared. (J.S.R.)

Each Borax-lIl fuel subassembly consists of a group of aluminum-clad aluminum-uranium alloy fuel plates arranged in an MTR-type array. The fuel plates are electric-resistance spot-welded to two aluminum sideplates and an aluminum central-support plate. An anuminum-0.6 wt.% boron, burnable poison strip is attached to each fuel subassembly. The poison strips are made by hot extruding a mixture of aluminum and elemental boron powders in the desired proportions. (auth)

Outside heat transfer coefficients for several horizontal tubes cooling an ordinary fluid containing a volume heat source by free convection were obtained experimentally. Water was used as the coolant, and a very dilute solution of HC1 was the bulk fluid. The basic equipment included a Lucite test cell which contained the bulk fluid, Cu screen grids through which an alternating current was passed to generate a volume heat source in the bulk and several horizontal 1/4 in. O.D. stainless steel tubes through which the coolant was pumped. Experiments were conducted using a single-tube, four-tube, and five-tube geometry. The heat transfer coefficients obtained were considered accurate within 8%. With single-tube cooling, the heat transfer coefficients were correlated by Nu = 0.49 (Gr Pr)/sup 1/4/. With four cooling tubes, the data were correlated by Nu = 0.59 (Gr Pr)/sup 1/4/, while with five cooling tubes the value of the coefficients in the correlation equation was Nu = 0.64 (Gr Pr)/sup 1/4/. (auth)

An analytical expression is presented which permits the prediction of the maximum nucleate heat flux in pool boiling of saturated or subcooled liquids. The numerical values of the empirical constants which appear in the Kutateladze and Borishanskii criteria for the burnout'' heat flux are derived from the theory. An analytical expression for the empirical function which appears in the correlation of Griffith is also derived. The hitherto unexplored features of transition boiling, i.e., the hydrodynamic instability, the well defined geometrical configuration and the frequency dependence are described, supported by experimental evidence, and used as the basis for the analytical work. The peak heat flux in transition boiling is shown to be limited by the combined effects of Taylor and Helmholtz instabilitiess whereas the minimum transitional heat flux is limited by the effect of Taylor instability ony. The analysis leads to the conclusion that because of the statistical nature of the ddsturbances and the bandwidth'' of the unstable wavelengths which govern the process, an inherent uncertainty exists in determining the exact value of the heat flux at burnout.'' The width of this uncertainty range is plus or minus 14%. The often noted poor reproducibility of experimental data on burnout'' can be …

Forced-convection heat transfer from an electrically heated Chromax wire oriented normal to a subcooled water flow was experimentally investigated with and without change of phase. Experiments were carried out up to the limit of burnout, and photographic observations were also made. The variables employed in this study range were the velocity from 1 to 6.8 ft/sec, subcooling in the range 140 to B0 deg F, and heat flux density up to 3.5 x 10/sup 6/ Btu/hr ft/. Pressures at the test section ranged from 15 to 30 psia. The results and conclusions are discussed. (auth)

By using experimental data, the quantities determimng the extent of dissolved H redistribution under a thermal gradient in Zircaloy were calculated. It is concluded that the phenomenon of hydride precipitation by means of thermaI gradient diffusion of dissolved H in Zircaloy fuel plates and cladding places much more severe restrictions on the allowable pre-operation H content of such elements than was hitherto suspected. The specific effects of operating conditions on H content of plates and cladding are presented in detail. (M. H.R.)

A Monte Carlo program for the IBM 704 is described. It is intended to be primarily useful in the computation of intensive reactor parameters. The program is suited to cylindrical geometry wherein parallel tubular regions are arbitrarily located in a matrix of concentric circular annular regions. Normally the annular regions correspond to moderator and/or reflector regions and the interjected tubular regions to fuel elements. The program requires a 32,768 word core memory amd four tape units. Package PK-1 from the library of General Electric packages is also required. (auth)

The masses of the isotopes of the heaviest elements have been calculated from known decay data in the region, extended by means of decay energies calculated from closed decay-energy cycles and estimated from the systematics of alpha and beta decay energies. The absolute values of the masses are based on the mass-spectrometrically determined mass of Pb{sup 208} and a few measured neutron binding energies. The half-life systematics of alpha decay and spontaneous fission are also presented, and some predictions of the properties of as yet undiscovered nuclides are made.

The exposure-time for fission fragment catcher foils, used in nuclear reactor power mapping, was arbitrarily set at 20 minutes. Work performed to evaluate this choice and to attempt an optimization of the exposure time is reported. A true optimum was not found. Forty minute runs are suggested, however, as a practical optimization and as an alternative to the 20 minute runs in current usage. (auth)

References to accelerators and accelerator technology in the technical literature from July 1954 through June 1957 are listed in Section 1, the bibliography. Most of the references are taken from Nuclear Science Abstracts, Chemical Abstracts, Physics Abstracts, and Electrical Engineering Abstracts. In Section H, accelerator installations throughout the world are listed together with the types of particles accelerated and the energy and other characteristics of the machines. (auth)

The economiics and physics of four schemes of pIutonium recycle in the Calder Hall type reactor are considered. The four possible schemes are: (I) to blend the Pu produced In a run with fresh naturaI U for a subsequeut run; (2) to alloy the Pu with somie diIuent metal and fabricate the alloy Into high heat- transfer elements morc like MIR or PWR-sced type elements and"spike' a subsequent load of fresh natural U elemients with these Pu elemicnts; (3) to recycle half the spent U as well as the Pu; and (4) to thke advantage of the extra reactivity gained fromi the recyeIed Pu to deerease the Iattice spacIng, thereby increasing the conversion ratio with the hope of increasirg the attaInabIe exposure. It was concluded that schcme (1) is the miost economiical. (W.D.M.)

A series of reactor frequency response measurements, relating flux or power level to a reactivity input function, were made to evaluate reactor stability for different values of power parameters. These parameters included: power level, steam pressure, and control rod position. The results were extrapolated to predict EBWR stability at higher operating powers. The experimental data may also be used to evaluate the thermodynamic and hydraulic constants. (authl

A revitew is presented of pretreatment methods with special attention to those useful at Eurochemic. Mechanical and chemitcal decanning methods presently in use or proposed for Al-, Mg-, stainiless steel-, and Zror Zr alloy-jacketed fuels are discussed. Darex, Sulfex, and Zirflex processes are included along with special methods ror U-- Mo and U- Zr fuels. (T.R.H.)

Creep properties of 15% cold-worked Zircaloy-2 at elevated temperatures sre presented. Work has continued on extrusion claddings flat plates utilizing the right-angle tooling. Study of uranium oxide structures has continued with emphasis being placed on determinng residule contents in UO/sub 2/. Four melting experiments were made using pure uranium dingot stock to meassure the total quantity of gas evolution occuring at various controlled temperature levels in the 2000 to presented in the Zr-1 wt. % uranium hydride system. Corrosion test results ane presented for gamma-phase urranium alloys. A program is presented that has the objective of obtaining fatigue information on Inconel along with variables of temperature, stress, strain, time, and cyclic frequency. Several experiments were performed to attempt to produce dense and homogoeneous bodies of UO/sub 2/ and La/sub 2/O/sub 3/. The electrical properties of UO/sub 2/-metal oxide systems sne given A study of phase relationships existing between the intermetallic phases of the U-Zr and U-Mo alloys is presented A solidstate study of the ternary system U-N-C is presented. (For preeeding periodd see BMI-1238.) (W.L.H.)

Although the oxides such as Al/sub 2/O/sub 3/, MgO, UO/sub 2/, ThO/sub 2/ , Be O, and ZrO/sub 2/ are used as refractory materials, very little reliable thermodynamic data predicting the stabilities of the gases in equilibrium with the solids at temperatures above 1700 deg C exist. In most cases the vapor pressures are not accurately known and in some cases the gaseous molecules are uncertain. Hence one experiences difficulties in attempting to predict ihe interaction of these oxides with the refractory metals such as tungsten and tantalum. The problems are made even more difficult because of a lack of reliable information concenning the gaseous oxides of tungsten and tantalum. As a means towards establishing the thermodynamic stabilities of these refractory oxides, the authors propose to survey the existing results and to describe some rather crucial experiments relating to the interaction of these oxides with tungsten and tantalum. Although not establishing accurate free energies, these experiments, neventheless, hnve shown conclusively the unreliability of some supposedly accurate thermodynamic properties because of a failure to examine the investigations in this manner. In addition, they indicate more reliable limits of free energies in certain cases. (auth)

This compilation of reactor physics constants, based on data available up to March 15, 1958, is the first publication of the Reactor Physics Constants Center (RPCC). The primary objective of the RPCC is the periodic compilation of the latest and best values of the constants, recipes, formulas, etc., which are necessary to calculate reactor characteristics. (W. D.M.)