Browsing by Author "Cairns, RC"
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- ItemA conceptual design study of a low throughput reprocessing facility for nuclear fuel(Australian Atomic Energy Commission, 1967-11) Cairns, RC; May, JR; Baillie, MG; Farrell, MSThe idea of reducing fuel reprocessing costs by changing reprocessing plant design philosophy is explained. It is shown how a significant reduction in unit reprocessing costs can lead to earlier recovery of nuclear material. A classification is given of some existing nuclear chemical reprocessing plants as a function of their maintenance philosophies. The feasibility of the rack concept is discussed for application to a conceptual low throughput reprocessing plant specifically designed for reprocessing fuel from the A.A.E.C.'s Dido-class reactor HIFAR. Laboratory and design development work is described. Preliminary cost estimates are given for a site at the Research Establishment, Lucas Heights, with maximum use of existing facilities, services, and plant. The study did not reveal any technical difficulties that would make the rack concept impractical. The concept of indirect maintenance for items of equipment which are likely to require frequent attention is technically feasible, and it appears possible to remove racks for repair of equipment by normal direct maintenance techniques. Additional development followed by plant construction and operation would be necessary to verify these conclusions and to establish any cost advantages. However, the cost estimates deduced at the start of the study did not change substantially during the course of the work.
- ItemDevelopment of a ten stage mixer settler for U235 solutions, Part 1(Australian Atomic Energy Commission, 1958-11) Baillie, MG; Cairns, RCThis report deals with the development of a 10 stage mixer settler. The unit is based on extraction conditions expected for processing HIFAR fuel elements, on which information is available, but the equipment can be used for other fuel types. Qualitative experimental work, which as necessary before the multistage unit could be designed with confidence, is reported for a single stage mixer settler. A brief review of the criticality problem for processing U235 enriched fuel is given and actual dimensions are specified for the case of HIFAR elements. The proposed work with the 10 stage unit is given.
- ItemDevelopment of a ten-stage mixer-settler for U235 solutions, Part 2(Australian Atomic Energy Commission, 1960-12) Baillie, MG; Cairns, RCExperimental work on a ten-stage mixer-settler is described. This includes the effects of impeller position and flow rate on its operation and the inactive extraction efficiency under conditions, such as are expected in the reprocessing of HIFAR fuel elements. Equilibrium data were determined for the systems used and a method for interface detection over a wide range of solution concentration developed. The mixer-settlers designed have been shown to be hydrodynamically practicable. It was found that interface height is controlled satisfactorily by correct positioning of the impeller above the mixer base and that the pump mix type of impeller recommended elsewhere is not essential.
- 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.
- 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.
- ItemSeparating small particles from liquids with hydro-cyclone, Part I - conclusions and recommendations arising from literature search(Australian Atomic Energy Commission, 1959) Cairns, RC; Thurstan, EG; Turner, KSA literature search has shown that a two stage hydrocyclone is required to give maximum concentration simultaneously with maximum clarification. For design purposes it is necessary to consider each operation separately. Concentration and clarification efficiencies have been proposed which will enable a choice of the major dimensions of a hydrocyclone to be made for each operation once experimental data are available for various systems. The programme of experimental work required to provide this information as well as information on operation methods is given.
- ItemSeparating small particles from liquids with the hydrocyclone, Part II - effects of major design variables(Australian Atomic Energy Commission, 1959-09) Cairns, RC; Thurstan, EG; Turner, KSHydrocyclone feed, overflow and underflow diameters are established for optimum concentration of solid and maximum clarification of liquid using an 11.5 ± 0.5 per cent, by weight suspension of sub-sieve barium sulphate in water. For a hydrocyclone with a nominal diameter (Dc) of 100 millimetres the dimensions for optimum concentration are: Feed diameter (Di) = 0.082 inch (Dc/5) Overflow diameter (Do) = 0.098 inch (Dc/4) Underflow diameter (Du) = 0.037 inch (Dc/11) Vortex finder outside Diameter (VFOD) = 0.197 inch and the dimensions for maximum clarification are: Di = 0.055 inch (Dc/7) Do = 0.079 inch (Dc/5) Du = 0.058 inch (Dc/7) VFOD = 0.197 inch Brief observations are given on the air core and the effects of feed solid concentration and feed solid particle size.
- 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.
- ItemStudies of small particle suspensions for L.M.F.R. Part VI concentration profiles across a bend and vertical pipe(Australian Atomic Energy Commission, 1958-09) Cairns, RC; Lawther, KRThis report completes the work on suspension studies for L.M.F.R. Concentration profiles have been measured for a tungsten suspension flowing through a smooth elbow and a vertical pipe. It has been shown that uniform suspension at a smooth elbow is not achieved for velocities up to 13.8 feet per second. Approximately four feet of vertical pipe is required after the smooth elbow to destroy the gradients set up in a horizontal pipe for velocities of approximately 3 and 13.5 per second. No evidence for "coring" 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.
- 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.
- ItemStudies of small particle suspensions for L.M.F.R. Part IV concentration gradients in flowing suspensions(Australian Atomic Energy Commission, 1958-07) Cairns, RC; Lawther, KRA radiometric method and the apparatus used to measure concentration gradients in flowing suspension are described. Both iridium 192 and thulium 170 sources have been used to measure gradients. Traverses of both a horizontal and a vertical pipe, in which a tungsten-water suspension was flowing, have been made. Plots are given for various velocities of the concentration distribution in percent tungsten by weight across the pipe at right angles to the direction of flow. Very turbulent conditions, with velocities in excess of 13.4 feet per second (Re > 161,000) in a 1-in, square pipe, are needed before uniform suspension would be achieved. At 13.4 feet per second, the difference in concentration from top to bottom concentration. Much larger concentration gradients exist at lower velocities. In vertical flow no measurable concentration gradients exist for mean velocities of 2.6 to 6.3 feet per second, (Reynolds number 29,000 to 74,000) in a 1-in square pipe. Striations noticed in previous work near the settling point were again observed in this work.
- ItemStudies of small particle suspensions for L.M.F.R. Part V. the effects of concentration, pipe diameter and solid density on the horizontal settling velocity(Australian Atomic Energy Commission, 1958-09) Cairns, RC; Turner, KSAdditional data have been collected for the horizontal settling velocities of small particles suspension. The effect of concentration, pipe diameter and effective density ratio have been determined. In almost all cases a moving bed is formed before a stationary bed. For small concentrations, up to several percent by volume, the effect of concentration is negligible.
- ItemStudy of major new research facilities, preliminary report(Australian Atomic Energy Commission, 1982-11) Cairns, RCThis paper reviews proposals and ideas on major new facilities which have been put forward in the past by AINSE and the AAEC for possible installation at Lucas Heights. Both research facilities and developmental projects have been included. The purpose of this preliminary report is to assemble in one document those proposals and ideas so that discussion by those responsible for new programs can proceed with a knowledge of past proposals. It is concluded that formal input should be sought on the proposals mentioned in this report (not all of which are now options) and any others by drawing together those competent in the fields from the AAEC and AINSE.