Browsing by Author "Isaacs, SR"

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    The audit of radioactive effluent released into the Woronora River, NSW
    (Australian Atomic Energy Commission, 1979-04) Isaacs, SR
    The radioactive effluent released from the AAEC Research Establishment at Lucas Heights into the estuary of the Woronora River, NSW, has been audited internally since 1961. This report describes the duties of the Effluent Audit Officer and the apparatus and analytical methods used.
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    Determination of zinc-65 in Lucas Heights effluent.
    (Australian Atomic Energy Commission, 1970-10) Isaacs, SR
    A method for the quantitative determination of zinc-65 in effluent is described. Zinc-65 is selectively extracted from a concentrate of effluent in HC1 using Aliquat-336 in xylene. The extracted zinc-65 is determined by gamma spectrometry. Using an 8 in x 4 in NaI(TI) cyrstal, concentrations as low as 0.07 x 10-12 Ci/ml can be determined, with + 10 per cent statistical accuracy.
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    Laboratory development of the grind-leach process for the H.T.G.C.R. fuel cycle, Part 1 - dissolution of urania-thoria fuel particles in nitric acid solutions.
    (Australian Atomic Energy Commission, 1965-09) Farrell, MS; Isaacs, SR
    The dissolution of 5 w/o UO2 in ThO2 fuel particles in nitric acid — fluoride solutions is a function of the Th02 dissolution rate. The Th02 dissolution rate has an apparent first order dependency on nitric acid concentration and a fractional order dependency on fluoride ion concentration. The apparent activation energy of the dissolution of the Th02 in 13M nitric acid — 0-05M fluoride is 19 kcal/mole. The presence of metal ions such as zirconium, aluminium, and beryllium inhibits the dissolution of the thoria. The order of inhibiting power is ZrlV > AlIII > BeII and this order is the same as the stability of their simplest fluoro — complexes, The addition of small quantities of sulphate also seriously inhibits the dissolution, precipitating thorium as Th(S04)2 , 4H20 and quantitatively removing the fluoride.
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    Laboratory development of the grind-leach process for the H.T.G.C.R. fuel cycle, Part II - dissolution of beryllia in nitric acid solutions
    (Australian Atomic Energy Commission, 1966-06) Farrell, MS; Isaacs, SR; Shying, ME
    the development of the grind—leach process for the processing of beryllia—based fuels requires a knowledge of the dissolution of beryllia in nitric acid. A kinetic study using powdered specimens has proved suitable for the investigation of this system. The parameters studied include particle size, agitation, temperature, acid concentration, the effect of the addition of fluoride and aluminium, and the effect of neutron irradiation of the beryllia. The dissolution of beryllia in nitric acid is controlled by a chemical reaction at the surface of the solid and has an apparent activation energy of 18 kcal/mole.
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    A study of the burial ground used for radioactive waste at the Little Forest area near Lucas Heights, New South Wales
    (Australian Atomic Energy Commission, 1977-12) Isaacs, SR; Mears, KF
    This report describes the laboratory and the field work connected with the study of the fate of radionuclides already buried at the burial ground of the AAEC Research Establishment at the Lucas Heights. The study complements and expands investigations made before the burial ground was established. The very slow movement of radioactivity from the buried waste is confirmed by environmental monitoring. The ion exchange capacity of the soil and the minimal ground water velocity both contribute to the retention of radioactivity in the area. A simple model is developed to demonstrate the capacity of the burial area for radioactive waste