Browsing ANSTO Publications by Issue Date
Now showing 1 - 20 of 1109
Results Per Page
- ItemEscape of fission products from slurry particles(Australian Atomic Energy Commission, 1956-02) Hickman, BSThe escape of fission products from fissile particles by recoil and by diffusion are discussed in general terms and equations governing these processes are derived. Experimental determinations of the mean free paths of the fission fragments and of the diffusion coefficients are reviewed. This data is then applied to a slurry of the composition under consideration viz. 1 or 2 atomic percent uranium, as metal or oxide in sodium. Tentative conclusions are drawn as to the optimum size for the slurry particles.
- ItemSuggestions for work on design of heat exchangers in liquid metal fueled reactors(Australian Atomic Energy Commission, 1956-06) Berglin, CLWThe report discusses the low heat transfer film coefficient on the secondary coolant side of tubular exchangers used in the calculations in AAEC-E-1. It suggests the types of heat exchangers which should be investigated in order to improve this coefficient and in turn to reduce the relative hold-up.
- ItemBehaviour of particles of U, UO2, and UC2 in a vertical tube through which liquid sodium is flowing(Australian Atomic Energy Commission, 1956-06) Berglin, CLWThis paper sets out to calculate the relation between the particle velocity and the fluid velocity in a vertical tube without making any assumptions as to the "apparent" viscosity of the suspension of particle in liquid sodium. The theory and calculations method is developed for suspensions of U, UO2 and UC2 in liquid Na in the temperature range 200º - 800ºC. At the moment, it does not help in assessing the performance of a circulating suspension in the primary coolant stream of nuclear power reactor.
- ItemA preliminary kinetic study of a sodium-beryllium-uranium circulating fuel reactor(Australian Atomic Energy Commission, 1956-11) Thompson, JJThe initial response of a 1:100:2000 U-Na-Be Reactor, operating at a power density of 1200 cals/cc/sec, to a sudden change in the fuel concentration in the circulating carrier, has been calculated on the assumption of constant inlet temperature and no delayed neutrons. The result confirmed that the peak temperatures and power can be accurately calculated by ignoring the moderator temperature rise, and that the approach to the new steady state values is given by the solution of the linearized equations. The slow moderator heating implies that the departure from the steady state are still large when the carrier and fuel have completed one transit of the external circuit. The assumption that the mean temperature is the arithmetic peak but overestimates the maximum power and outlet temperature excursions by 15 1/2% and 7% respectively.
- ItemA note on the response of a circulating fuel reactor to random fluctuation in fuel concentration(Australian Atomic Energy Commission, 1956-11) Thompson, JJA simplified model of a Uranium "Sodium" Beryllium circulating fuel reactor has been analysed to determine the root mean square power and temperature fluctuations due to random variations in the inlet fuel concentration. The results indicate that limits of ± 2% on the fuel concentration should reduce the mean square power excursion, due to this cause, to less than ½%. The calculations based on assumptions only, as regards the specification of the statistical nature of the fuel concentration, but the method can be used to obtain more realistic estimates when experimental evidence becomes available.
- ItemPreliminary design of annular tube heat exchangers for circulating fuel systems(Australian Atomic Energy Commission, 1957-02) Berglin, CLWThis paper follows up one of the suggestions in AAEC-E-2, and shows that the annular tube heat exchanger for circulating fuel systems is practical, compact and has a reasonable out-of-core holdup.
- ItemParticle size analysis of tungsten metal powder.(Australian Atomic Energy Commission, 1957-05) de Bruin, HJ; Cairns, RCA method of particle size analysis for sub-sieve, tungsten metal powder has been developed using the Andreason pipette. Use of 1/4 percent by volume of tungsten powder in demineralised water gives minimum agglomeration. The method is useful for comparing the distribution of different batches of tungsten powder. No correlation between results from this method and the microscopic counting method used by the suppliers of the powder was found.
- ItemStudies of small particle suspensions for L.M.F.R. Part I - fluid flow with suspensions simulating the U-Na systems(Australian Atomic Energy Commission, 1957-08) Cairns, RC; Turner, KSVelocities of 2.5 to 2.9 feet per second (76 to 88 centimeters per second), are needed to prevent settling of tungsten powder in a 1-in i.d. horizontal pipe from aqueous suspensions containing 6.1 to 7.0 percent by weight of tungsten. In one instance a narrow moving bed was observed at a velocity of 3.8 feet per second for a suspension containing 5.0 percent of tungsten but the formation of a moving bed as not reproducible. Settling has been observed at Reynolds numbers as high as 36,300. The equation of Dallavale, (4), (5) suitably modified predicts settling velocities in a horizontal pipe of the same order as those found experimentally for dense solid, micron-sized particles suspension. For fully suspended flow, the friction factors lie approximately 10 percent above the smooth tube, normal liquid curve. It was not found necessary to consider non-Newtonian relationships to correlate the pressure drop data. At mean Reynolds numbers above approximately 3500 "streamlines" ha been observed in the lower half of the pipe for fully suspended flow. This phenomena is discussed but a full quantitative theoretical explanation is needed toothier with further experimental work.
- ItemDischarge coefficients for the No.1. sodium loop venturi meter.(Australian Atomic Energy Commission, 1957-10) Cairns, RCDischarge coeffiicients for the Venturi meter designed for use on the No. 1 Sodium Loop are reported for throat Reynolds numbers up to 298,000.
- ItemSome design data for gamma shielding in N.S.W.(Ausralian Atomic Energy Commission, 1957-12) Ebeling, DRIt is indicated that the use of pits and ponds is the cheapest method of containing active materials but that many things can make these methods impracticable. Concrete is thought to be the most generally useful material for above-ground shields and high density shields can be made comparably cheaply by using steel punchings, ilmenite sand, iron ore or a combination of these. Lead and cast iron are among the most expensive shielding materials but they can often be justified because of their compactness. Costs are included wherever possible.
- ItemH.T.G.C. fuel and moderator material irradiation programme.(Australian Atomic Energy Commission., 1958-01) Hickman, BSProbable mechanisms of irradiation damage in fuel and moderating materials of interest to the H.T.G.C. Reactor programme are discussed. A programme is outlined for investigations into irradiation damage in H.T.G.C. fuels and moderators. The experimental methods to be used are briefly outlined.
- ItemStudies of small particle suspensions for L.M.F.R. Part II - correlation of horizontal settling velocities(Australian Atomic Energy Commission, 1958-02) Cairns, RCThe available experimental data for the horizontal settling velocities of suspensions with particles of small size have been collected. These have been compared with the velocities calculated from the several equations existing in the literature for predicting horizontal settling velocities. No consistent agreement between he experimental and calculated velocities has been found. Using the effective density ratio, defined as the ratio of the difference in density between solid and liquid to the density of the liquid, the experimental values have been correlated satisfactorily. Further data is needed before a generalised correlation for suspensions can be established.
- ItemThe thorium-apans complex: a spectrophotometric study(Australian Atomic Energy Commission, 1958-02) Palmer, ARThe analytically useful complex formed by thorium and APANS [1-(o-arsonophenylazo)-2-naphthol-3:6 disulphonic acid] has been studied by a spectrophotometric method. The complex is shown to be of the 1:2 type and it equilibrium constant measured.
- ItemEstimation of traces of nickel in sodium metal.(Australian Atomic Energy Commission, 1958-02) Florence, TMA simple and sensitive method is described for the determination of traces of nickel in sodium metal. The nickel is complexed with potassium cyanide and the absorption measured spectrophotometrically at 268 mµ. Interference of iron and chromium is removed by precipitation of the hydroxides from homogeneous solution. This method should be applicable to a wide range of materials.
- ItemStudies of small particle suspensions for L.M.F.R. Part II fluid flow with suspensions simulating the UBe13-Na system(Australian Atomic Energy Commission, 1958-02) Cairns, RC; Turner, KSSuspensions of barium sulphate in water at concentrations of up to 16.5% w/w were circulated in a 1-inch loop to simulate the behaviour of the UBe13-Na system for L.M.F.R. In a horizontal pipe the mean velocity for the formation of a moving bed was 1.6 feet per second and the mean velocity for the formation of a stationary bed was 1.4 feet per second. The corresponding mean Reynolds numbers were 15,000 and 13,000 respectively. No agreement as found with Dallavalle's (2) equation previously suggested (1) for calculating the horizontal settling velocities. For fully suspended flow, friction factors were the same as for clean water the density and viscosity terms in the Reynolds number related to the suspension. The validity of the Orr and Dallavalle (5) viscosity equation for such systems was confirmed and non-Newtonian relationships were not required. Striations similar to those previously reported for the tungsen-water system, were observed before and during settling.
- ItemDetection of traces of oxygen in gases: methylene blue method.(Australian Atomic Energy Commission, 1958-03) Davis, PSA simple method for the detection of traces of oxygen in gas streams is described. The method is based on the colour change which occurs when leuco-methylene blue is oxidised to methylene blue. Suggested uses of the method are in argon-arc welding and glove-box work where oxygen must be excluded.
- ItemConstant current source for automatic coulometric titrations(Australian Atomic Energy Commission, 1958-03) Palmer, AR; Pryor, AWA simple, but versatile constant current source for automatic coulometric titrations is described. The unit is suitable for use with a commercial automatic pH titrimeter and will accommodate wide variations of mains voltage and load resistance. Coulometric titrations may be carried out "fast" or "slow" with a choice of four current ranges (2-37 mA) for titrations up to or near the end point. A slow "1mA" range is available for approaching the end point and the titration of microgram amounts of material. The automatic pH titrimeter provides for automatic change fast to slow generation of reagent and for stopping the titration at selected end points. The utility of the equipment has been demonstrated by the estimation of chromium with electrogenerated ferrous iron. The unit should be suitable for many other coulometric titrations.
- ItemCalculations of thermal stresses in HIFAR reactor shell structure(Australian Atomic Energy Commission, 1958-05) Ebeling, DR; Holt, NDThermal stresses will be included in the circular crane beam by expansion of the reactor shell. Calculations assuming 100ºF temperature difference shows that thermal stresses of about 11000 p.s.i are probable and that the combined stresses due to expansion and crane load, are close to the maximum allowable.
- ItemDetermination of traces of oxygen in sodium metal by infrared spectrophotometry: Part 1.(Australian Atomic Energy Commission, 1958-06) de Bruin, HJ; Smythe, LEThe principal methods for the determination of traces of oxygen in sodium metal.