Browsing by Author "May, FG"

Now showing 1 - 6 of 6
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    Case studies for special applications
    (Australian Nuclear Science and Technology Organisation, 1991-10-11) May, FG
    Not available. Original proceedings held by ANSTO Library.
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    Fume cupboard problems, testing and solutions
    (Australian Nuclear Science and Technology Organisation, 1991-10-11) May, FG
    Not available. Original proceedings held by ANSTO Library.
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    Methyl iodide penetration of charcoal beds: variation with relative humidity and face velocity
    (Australian Atomic Energy Commission, 1974-09) May, FG; Polson, HJ
    The retention of methyl iodide in charcoal beds was found to vary with the distance from the leading edges of the beds. Near the leading edges, retention was less than in the deeper regions, probably due to the chemi-sorption of competing vapours in the airstream drawn through the beds. One of the poisoning agents was identified as di-methyl sulphate vapour. The penetration of methyl iodide fell exponentially with distance in the deeper regions of the beds. The slope of the penetration curves in these deeper regions was dependent on the relative humidity and the face velocity in a more complex manner than the simple relationship assumed in the 'Stay Time" concept. An empirical formula, which gave the slope of the penetration curve within a standard deviation of 7 per cent, was derived to correlate the parameters over the range of practical interest, i.e. 30-99 per cent relative humidity and from 1.1 m s-1 down to at least 0.16 m s-1, and probably much lower. The uncertainty in the results could have been caused by variations within the batches of charcoal. A formula was derived to translate the results of an in situ test at a measured flowrate and humidity into an expected performance at high humidity and any other flowrate. The expression is independent of the slope of the penetration curve and the thicknesses of both the poisoned and unpoisoned regions of the bed, which suggests that it may be valid even for heavily poisoned beds.
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    Revised radioactive airborne effluent discharge limit for the Lucas Heights Research Laboratories
    (Australian Nuclear Science and Technology Organisation, 1989-09) Petersen, MCE; Clark, GH; Bailey, GM; May, FG
    The Australian Nuclear Science and Technology Organisation, formerly the Australian Atomic Energy Commission, is authorised under the NSW Radioactive Substances Act to release limited quantities of radioactive airborne effluent into the atmosphere from its facilities at the Lucas Heights Research Laboratories (LHRL). This authorisation is about twenty years old. This report proposes a revised site-wide airborne effluent discharge limit for the LHRL. The revised discharge limit is based upon the panoply of current International Commission on Radiological Protection (ICRP) and National Health Medical Research Council (NH & MRC) recommendations. It takes account of the operational changes at the LHRL and developments in radiation dosimetry and meteorology. The development and technical basis of the revised discharge limit, together with its relation to the ICRP recommendations, is briefly given. The formal discharge limit is to be approved by the NSW Radiological Advisory Council. The discharge limit consists of three components. First, a definition of the discharge limit expressed in terms of a fraction of the recommended ICRP dose limits. This limit is supported by, second, a compliance procedure and, third, a reporting procedure. In addition to the revised discharge limit, a number of operational and safety measures have to be further developed under the direction of ANSTO Management. The development of 'reference' levels' recommended by the ICRP is briefly described. In the present context, two reference levels for the quantities of activity released from each source will be established. The levels operate effectively like quality control measures in industry. They require certain operator actions if they are exceeded. The doses to individuals which are estimated for releases at the reference levels of releases of activity are well within the revised dose limits. From an operational point of view, these levels will vary with changing operations.
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    Source term and behavioural parameters for a postulated HIFAR loss-of-coolant accident
    (Australian Atomic Energy Commission, 1987-01) May, FG
    The fraction of the fission product inventory which might be released into the atmosphere of the HIFAR reactor containment building (RCB) during a postulated loss-of-coolant accident (LOCA) has been evaluated as a function of time for each classification of airborne radioactivity. This appraisal will be used as the source term for a computer program which uses realistic attenuation of the fission product aerosol in a single compartment model with a defined leakrate to predict possible radioactive releases into the environment in a hypothetical bounding case reactor accident which is rather more severe in all major aspects than any single LOCA. Also given are the parameters governing the attenuation of the aerosol and vapours in the atmosphere of the RCB so that their behaviour may be accurately modelled. The source terms for several other types of accident involving the meltdown of fuel elements have also been considered but in less detail than the LOCA case. In some of the cases the fission products are released directly to atmosphere so there is no attenuation of the release by deposition within the RCB.
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    Stack monitoring at ANSTO and comparison with international guidelines
    (Australian Nuclear Science and Technology Organisation, 2002-09) Mukherjee, B; May, FG; Clark, GH
    This report reviews the sampling systems at ANSTO in terms of current international guidelines for the design and operation of stack monitoring at nuclear facilities. A review of the literature and enquiries overseas have revealed the principal international guidelines for stack sampling and on-line monitoring are: 1. Monitoring of Radioactive Releases to Atmospheres from Nuclear Facilities, Technical Guidance Note M11, UK Environmental Agency 1999. This Technical Guidance Note provides guidance on the monitoring of airborne releases from nuclear facilities regulated under the UK Radioactive Substances Act (RSA 1993). For sites in England and Wales, the authorisations are issued by the Environmental Agency and in Scotland by the Scottish Environmental Protection Agency. 2. Sampling and Monitoring Releases of Airborne Radioactive Substances from Stacks and Ducts of Nuclear Facilities. American National Standard ANS/HPSN13.1.1999.