The limitations and operating techniques which were in effect at ANPD for the prevention of criticality accidents are summarized. The standards followed by the atomic industry were followed; however, the safe mass of U/sup 235/ moderated with beryllium oxide and hydrogeneous materials was based upon criticality experiments conducted at ANPD. Although the guide was primarily for the use of the ANPD nuclear safety control organization, it may also be of assistance to designers and operating management in maintaining nuclear safety. (auth)

This report talks about Analytical and preliminary design studies of nuclear rocket propulsion systems. Volume VI. Compilation of hydrogen properties,

Methods and techniques for measuring the conductances of reactor solutions at elevated temperatures and to interpret the results with electrolytic solution theories are discussed. Criteria applied to room-temperature conductances for determining complete ionization of 1-1 electrolytes were applied to the Noyes high-temperature conductance data obtdined on NaCl, HCl, KCl, NaOH, AgNO3, and H/sub 3/PO/sub 4/ solutions. lt was found that the first four electrolytes behave as strong electrolytes up through temperatures of 218, 218, 281, and 156 deg C, respectively. Application of the Bjerrum theory showed that, somewhat above each of these temperatures, these electrolytes begin to associate by ion-pair formation. H/sub 3/PO/sub 4/ solutions associated at room temperature and above. AgNO/sub 3/ solutions appeared to asscciate at all temperatures. The equivalent conductances and infinite dilution and the dissociation constants for each of the electrolytes were calculatsd. An apparatus was constructed and measurements were made on the conductances of LiOH and NH/sub 4/OH solutions over the temperature range of 100 to 520 deg F. Equivalent conductances at infinite dilution were calculated. The pH of reactor coolants using LiOH or NH/sub 4/OH was calculated from the disscciation constants for water, LiOH, and NH/sub 4/OH at elevated temperatures. (auth)

The boron--carbon equilibrium diagram was determined by x-ray, metallographic, and thermal analysis of sintered and arc-cast alloys. A single carbide having a range of solubility from approximately 9 to 20 at.% carbon and melting congruently exists in the system. The terminal solubility of carbon in boron is 0.1-0.2 at.%. The freezing reaction between boron and the carbide is a degenerate peritectic --eutectic reaction at the composition and melting temperature of elemental boron; there is a eutectic reaction at 29 at.% carbon and 2375 deg C. No allotropy of boron was observed. (auth)

Fuel Fabrication and Evaluation. Nearly stoichiometric, low nitrogen- content UC was synthesized in the plutonium glove box atmosphere. PuC and PuC- UC preparation studies were initiated by the oxide-carbon reaction. UC with nickel additions lowered required sintering temperatures, improved density over control straight UC samples, but did not improve densities over those obtained previously with UC. Microprobe analysis of niobium and 21/4 Cr- 1 Mo compatibility samples tested 4,000 hr at 820 deg C, showed no uranium penetration. Irradiation Test. The W1-1 capsule containing two clad UC specimens continued operation to 11,000 MW-d/ton by the end of April. The W1-2 capsule was inserted in WTR, but had to be removed after a short time because of a radioactive gas leak. Plutonium Facilities. The facility at The Carborundum Company started operation with plutonium in March. Modifications and maintenance continue to be required and are being completed with minimum effect on experimental work schedules. The major modifications of the facility at NDA, the once-through nitrogen and helium systems, were completed and initial operation is satisfactory. A performance test was initiated prior to operations with plutonium. Design and construction of equipment for the furnace box are in progress. (auth)

Carrier recombination and annealing of radioinduced recombination centers were investigated for both n- and ptype Ge. The experimental results are explained by a model in which recombination occurs at 0.36 ev above the valence band in gamma -irradiated, n-type Ge; the position of this level is shifted slightly downward for neutron-irradiated Ge. Trapping levels occur in As-doped Ge (at 0.17 ev above the valence band) which are not present in Sb-doped Ge. For p-type Ge, an energy level present in unirradiated Ge acts as a trapping center. A value for the electron capture cross section of n-type Ge is derived: 7 x 10/ sup -//sup 1//sup 9/ cm/sup 2/. The annealing properties of Sb- and As-doped Ge are very different. A model for the annealing results is given in which irradiation produces three major types of defects: interstitials, vacancies, and vacancy-interstitial pairs. The properties of each defect type are described. Association of vacancies with doping atoms is discussed. (D.L.C.)

"Ultrasene" typically contained 57 wt % branched paraffins and cycloparaffins, 40 wt% n-paraffins, 3 wt% aromatics, and less than 0.1 wt% olefins. The n-paraffinic fraction from "Ultrasene" was stable to chemical and radiolytic degradation, whereas the combined branched paraffinic and cycloparaffinic fraction, and the aromatic fraction, were significantly less stable. (auth)

Corrosion tests were run on some commercial grade metals, an alloy steel, stainless steels, chromium-- nickel-iron alloys, nickel base alloys, cobalt base alloys, and a chromium-- nickel-- cobalt-- iron ailoy in the system: leadlead chloride-lead chloride vapor at 528 deg C under an argon atmosphere. The following metals and alloys showed a corrosion rate of nine mils per month or less and did not suffer intergranular or other localized attack: tantalum, Incoloy 804, Hastelloy F, Carpenter-20 (Cb), stainless steels 316L, 318 Cb, Haynes Alloy 25, and Haynes Multimet (auth)

Critical experiments were performed with two assemblies simulating a cold clean, and an end-of-cycle,- Argonne High Flux Reactor, core. Data were obtained for flux distributions; cadmium ratios; temperature and void coefficients; and control rod, beam hole, and reflector worths. The data obtained furnished confirmation of theoretical predictions. The peak 2200-m/sec flux per unit power was measured as 3 x 10/sup 7/ n/(cm/sup 2/)(sec)(watt) for both cores. The two cores had internal H/sub 2/O thermal columns, 12.7 cm x 12.7 cm x 50.8 cm. These were enclosed by 100-liter fuel zones. The radial reflector was 90% beryllium containing 10% H/sub 2/0 plus Plexiglas by volume. The top and bottom reflectors were H/sub 2/O. The critical mass was 3.58 kg U/sup 235/ with a 1.16 metal-towater ratio in the fuel zone. The critical mass with a 1.60 metal- to-water ratio, taking into account 34.3 kg Type 304 stainless steel, was 7.15 kg U/sup 235/. (auth)

The need for the first core for EBR-11 resulted in the design and construction of the Initial Fuel Loading Facility for this reactor. The plant was built to provide the required initial loading, to train personnel, and to test prototype equipment for the remote reprocessing of fuel materials in the EBR- II Fuel Cycle Facility. The facilities include: remotely manipulated melting, casting, and pin processing equipment, a degreaser, hoods and their atmospheric control system, a gas-purification system, fuelelement-assembly equipment, mold- preparation and balance room, bonding furnaces, a maintenance shop, and a change area. (auth)

The diffusion of tracer amounts of chromium in gamma uranium was studied by the radioactive tracer-sectioning method. The temperature dependence of the diffusion coefficient D is given by D = 1.98 x 10/sup -3/ exp(--2l,800/RT)cm/sup 2// sec, in poor agreement with the data of Mosse, Levy, and Adda. Possible reasons for the discrepancy are discussed, and it is concluded that the present data are to be preferred as a basis for theoretical studies of the diffusion of tracers in gamma uranium. The difference between the activation energy and that for self-diffusion is also discussed; no conclusions are reached. (auth)

A kinetic model of the primary loop of a multi-pass pressurized water reactor power plant is developed to evaluate, by analog computer techniques, the transient response characteristics under conditions of steam generator load and reactor control rod perturbations. Using the 2-pass 28 Mw(t) SM-2 reactor as a typical plant, transient behavior patterns are illustrated and examined for a variety of load inputs, variations in plant constants, and analog model simplifications. (auth)

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A bibliography of 240 references is presented on the extrusion of U, U alloys, and U compacts. The references were taken from Nuclear Science Abstracts and cover the period Jan. 1951 tc June 1961. (D.L.C.)

A force multiplier was designed. This piece of equipment was made to increase the gripping force presently available in the Model 8 master slave. The force multiplier described incorporates a clamp which can be quickly attached to and detached from the master slave hand. (auth)

A method is presented for the aerothermodynamic optimization of the net power and/or propulsive thrust per unit reactor free flow area of a nuclear power plant operating on the Brayton cycle. A system so optimized will translate into the minimum size, therefore the minimum weight, nuclear system for any selection of reactor materials, lifetime, and fuel loading. The theory and development of the thermodynamic optimization process, the importance and effect of various parameters, and specific methods to be employed in the optimization of the various forms of the Brayton cycle are discussed. A sample calculation for the case of the ramjet application is included. The results of the application of these techniques to any Brayton cycle system may be used in conjunction with nuclear sizing methods, for beryllia-moderated reactors, to determine the required reactor size as a function of fuel loading and reactivity requirements. (auth)

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Techniques are described for obtaining x ray diffraction information on active metals at high temperatures. One method is used to 1000 deg C with rare earths; the other method is used to 2200 deg C with tungsten, and to 1400 deg C with some f the higher melting rare earths. The latter approach permits simultaneous measurement of resistance of the specimens vs temperature and the diffraction pattern, which facilitates the characterizing of the high temperature forms of the metals. (auth)

The resistsnce of the water --tributyl phosphate (TBP) interface to diffusion of uranyl nitrate was investigated by a photographic photometric technique. The resistance was below the limit of detectability in the experiments, even with a surface-active agent present in the system. The sensitivity of the experiments established an upper bound for the interfacial resistance to diffusion equivalent to that of a 25- mu film of TBP under steady- state diffusion. The results indicated that the rate-limiting step in solvent extraction of uranyl nitrate from water by TBP is transfer of the diffusing species between the interface and the bulk phase rather than across the interface. In the experiments a steady-state concentration profile was established across an interface by providing a source of uranyl nitrate on one side and a sink on the other in a special cell. Uranyl nitrate diffused along the concentration gradient and hence across the interface. A resistance to diffusion by the interface would be manifest as a departure from equilibrium of the uranyl concentrations immediately adjacent to and on either side of the interface. Accurate values of the interfacial concentrations at steady state were obtained by extrapolating the profile obtained from a few point measurements on …

A preliminary chemical flowsheet was developed on a laboratory scale for the preparation of feed and two solvent extraction cycles for the processing of Si-containing Al--U alloy, 20% enriched, fuel elements. Major process steps include dissolution of the fuel assembly in Hg-catalyzed ritric acid, removal of silica by coagulation during feed clarification, and recovery of U and pu by extraction with a tributyl phosphate solvent and selective stripping. Criticality control in existing process equipment is maintained by the use of internal neutron poisons and concentration control throughout the process. (auth)

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A study was made of the neutron diffraction patterns obtained from Kr liquid under seventeen conditions of temperature and pressure at 117 to 210 deg K. The low temperatures were used because the diffraction patterns and the corresponding radial distribution functions are more sharply defined near the liqdid triple point. (J.R.D.)

A new Zircex flowsheet is proposed in which the nonvolatile products from hydrochlorination of uranium-zirconium alloys are chlorinated with carbon tetrachloride, thereby avoiding the loss of 1 to 6% of the uranium observed in engineering development studies of the older flowsheet for STR fuel in which the hydrochlorination residue was dissolved in nitric acid. Other potential advantages of the new flowsheet include decreased corrosion and elimination of possible explosions between uranium--zirconium alloys and nitric acid. The uranium may be recovered by aqueous dissolution and solvent extraction or by gas- phase fluorination at 200 to 400 deg C of uranium chlorides. (auth)

The problem of determining the dynamic properties of the steam void fraction undergoing random variations at a particular location in a boiling channel was studied. Emphasis was placed on a gamma attenuation method and on a method employing sensitive flowmeters at suitable locations of the channel. The dynamic properties of interest were the autocorrelation function and the power density spectrum of the variations. Equations were derived for computing the desired quantities on the basis of gamma records obtained during actual boiling experiments and from runs with empty and full, nonboiling channels. The equations consider the statistical variations of the gamma source and detector. A procedure was outlined for estimating the measurement effort to obtdin a predetermined accuracy. Two models were developed to correlate the variations of flow with fluctuations of the steam void. Both models were based on the mass continuity equation for a two-phase fluid. The simpler model leads to a first- order, linear differential equation with randomly varying coefficients. The desired quantities can be computed from the equation. The second model leads to a linear integral equation of the third kind. This equation relates the power density spectrum of the void fraction with the spectra of the water …