ANSTO :: Browsing by Author "Airey, PL"

Browsing by Author "Airey, PL"

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Alligator Rivers analogue project an OECD/NEA international project
(The Institution of Engineers Australia, 1994-05-01) Duerden, P; Pescatore, C; Airey, PL
The Koongarra uranium deposit in the Alligator Rivers Region of the Northern Territory of Australia was studied as a natural analogue of the far field behaviour of high level waste repositories following groundwater ingress. A number of mathematical modelling approaches were developed for processes as diverse as groundwater transport, host rock weathering, radionuclide sorption, evolution of the uranium dispersion fan and the distribution of uranium series nuclides between mineral assemblages in weathered host rock. Some of these models are relevant to performance assessment at the level of individual processes and subsystem performance. Through the project, new insights into the application of the natural analogue approach to the assessment of potential waste repository sites were obtained.
ANSTO's radioactive waste management policy: preliminary environmental review
(Australian Nuclear Science and Technology Organisation, 1996-05) Levins, DM; Airey, PL; Breadner, B; Bull, PS; Camilleri, A; Dimitrovski, L; Gorman, T; Harries, JR; Innes, RW; Jarquin, E; Jay, G; Ridal, A; Smith, AM
For over forty years radioactive wastes have been generated by ANSTO (and its predecessor the AAEC) from the operation of nuclear facilities the production of radioisotopes for medical and industrial use and from various research activities. The quantities and activities of radioactive waste currently at Lucas Heights are very small compared to many other nuclear facilities overseas especially those in countries with nuclear power program. Nevertheless in the absence of a repository for nuclear wastes in Australia and guidelines for waste conditioning the waste inventory has been growing steadily. This report reviews the status of radioactive waste management at ANSTO including spent fuel management treatment of effluents and environmental monitoring. It gives details of: relevant legislative regulatory and related requirements; sources and types of radioactive waste generated at ANSTO; waste quantities and activities (both cumulative and annual arisings); existing practices and procedures for waste management and environmental monitoring; recommended broad strategies for dealing with radioactive waste management issues. Detailed proposals on how the recommendations should be implemented is the subject of a companion internal document the Radioactive Waste Management Action Plan 1996-2000 which provides details of the tasks to be undertaken milestones and resource requirements.
Application of neutron activatable tracers (NATs) for cohesive sediment transport studies in contaminated estuaries
(International Atomic Energy Agency, 2004-10-29) Hollins, SE; Szymczak, R; Airey, PL; Peirson, WL; Payne, TE
ANSTO and the University of NSW Water Research Laboratory (WRL) are investigating the migration of contaminants associated with cohesive sediments in Homebush Bay, Sydney. The study area is a highly urbanised and industrialised catchment with a long history of contamination [1]. Until 1890, when an ocean outfall was commissioned, domestic and industrial waste was discharged directly into Sydney Harbour [2]. Heavy metals and other hydrophobic pollutants have a distinct tendency towards solid phase partitioning. This means that the majority of heavy metals in the estuary are linked to particulates rather than occurring in the dissolved phase. Hence, in order to assess the impacts of the pollution and develop a scientific basis for remediation it is necessary to understand processes that resuspend and disperse the contaminated sediments. The study approach involved the evaluation of the numerical model of the processes using activatable tracer techniques [3]. An ideal tracer binds to the material of interest with high integrity and is detected with high sensitivity and selectivity. Tracers can be used to study sediment transport over extended periods and are therefore ideally suited to observing the impact of extreme weather events on sediment mobilisation by monitoring the distribution of the label before and after the event. The tracer must not only adhere to the cohesive sediment with high integrity but must be detectable with high efficiency, high sensitivity and relatively low cost. Identification of the optimum activatable tracer involved an assessment of the nuclear (Table I) and sorption properties. The implementation of the tracer study involved (a) labelling sediment from the study area with indium-115 in the laboratory and equilibrating for 3 weeks; (b) choosing a site where bathymetric surveys indicated significant recent accretion; (c) injection of the labelled sediment into an accurately located site in Homebush Bay (Fig. 1); (d) undertaking three surveys over the subsequent months; (e) analysis of samples via irradiation in the Fast Access Neutron facility in ANSTO’s research reactor, HIFAR and gamma counting on a High Purity Germanium detector3; and (f) data processing, where the tracer concentrations were contoured using the Surfer© routine and interpreted in terms of advective and dispersive transport using a Gaussian approximation (Fig. 2). Information on vertical transport was obtained by coring. These results are being used to evaluate a three-dimensional finite element model of the study area [4]. Estimates have been made of the aerial dispersion coefficients, of the surficial mixing due to bioturbation and of advective transport. This paper will focus on the optimum choice of the tracer for cohesive sediment transport studies and some early results.
Assessment of the radiological health risk associated with ANSTO effluent release: including the reuse of tertiary treated sewer water and sludge and the impact of effluent entering local waterways with sewer surcharge
(Australian Nuclear Science and Technology Organisation, 2002-03) Airey, PL; Domel, RU
An analysis has been made of the radiological consequences of the release of ANSTO's aqueous discharge to the Cronulla Sewerage System. This is in response to Condition 10 of the Environmental Impact Statement supporting the Replacement Research Reactor. The analysis covers the release of effluent under normal conditions, the release of effluent as part of a sewage surge during periods of high rainfall, and the impact of the decision by Sydney Water to recycle treated sewage sludge and sewage water.
Dating, mass spectrometry and nuclear science: a proposed new facility at Lucas Heights.
(Australian Atomic Energy Commission, 1984-01) Bird, JR; Airey, PL; Boldeman, JW; Cohen, DD; Duerden, P
It is proposed that the AAEC install a high-technology, multi-user facility based on an 8 MV tandem accelerator to provide new capabilities in the following fields: (a) Radioisotope dating and ultra-sensitive trace element determination in isotope hydrology, salinity, sedimentology, erosion, actinide transport and materials studies. (b) Physics studies for the development of methods of applying nuclear materials safeguards, the provision of neutron dosimetry standards, measurements of precision data for radiation interactions, and the development of new methods for radioisotope dating. (c) Development of nuclear and ion beam techniques with applications in occupational health, biomedicine, materials modification, industrial problems and other fields. (d) Special requirements for accelerator-based radiocarbon dating of geological and archaeological samples not provided by other laboratories, coordinated by the Australian National University. These primary objectives include collaborative projects with the Bureau of Mineral Resources, Geology and Geophysics (BMR), the NSW Water Resources Commission (NSWWRC) and, under the auspices of the Australian Institute of Nuclear Science Engineering (AINSE), with Australian universities and other advanced educational institutions. Existing inter-regional programs in hydrology and neutron physics would also be served by the proposed facility making possible an expansion in the scope of joint projects with other countries in the SE Asian region.
Evolving role of radiotracers in coastal zone studies
(Pergamon-Elsevier Science Ltd., 2003-03-01) Airey, PL; Hughes, CE; Kluss, T; Duran, EB; Miller, BM; Chiuenta, S; Nielsen, AF; Hollins, SE
Recent advances in the off-shore radiotracing program in the Asia Pacific region are described with examples from the Philippines, Thailand, Hong Kong and Australia. Advances are driven by changing requirements from the user community which include: (1) the need to experimentally evaluate the output of numerical models underpinning engineering and environmental investigations; (2) the need to address increasingly sophisticated questions posed by researchers into coastal ecosystems; and (3) the need to respond to pressures from regulators to minimise the level of tracer released to the environment. Four stages in the recent evolution of tracer technology are identified. Crown Copyright © 2003 2003 Published by Elsevier Science Ltd.
The evolving role of radiotracing in integrated coastal zone management investigations
(National Association for Applications of Radioisotopes and Radiation in Industry, 2001-12-01) Airey, PL; Hughes, CE; Hollins, SE; Kluss, T
A review is presented of the off-shore radiotracing program at ANSTO. Special reference is made to the impact that sophisticated numerical modelling is making to the design of tracer studies underpinning engineering and environmental investigations in the coastal zone. Much of the research is designed to reduce the freedom modellers have in setting parameter values. Emphasis being placed on studying of the fate and behaviour of particulates and cohesive sediments, on measuring the impact of wind fields on transport and on obtaining field measurements of model parameters such as hydrodynamic shear stress. (author)
The future of radiotracing
(International Atomic Energy Agency, 2015-01-01) Airey, PL; Hughes, CE
Radiotracing has enormous potential to provide data to underpin environmental management in aquatic ecosystems. The use of tracer data to validate numerical models, improvements in data acquisition and new tracer forms provide the basis for the future of radiotracing. However, an increasing regulatory burden, reduction in tracer availability and a loss of technical expertise threaten this field of study. Standardisation of tracer approaches where possible and new work on assessing the impact of radiotracers on non-human biota are two areas that may enable the future use of radiotracers at a field scale in engineering and research applications. © The authors.
Nuclear geophysiology: stable water isotopes as evaluators of hydroclimate predictions in the Murray-Darling basin
(Australian Institute of Physics, 2005-01-31) Henderson-Sellers, A; Airey, PL; McGuffie, K
Isotopic data from two end-range and one central aquifer in the Murray Darling Basin are used to determine precipitation intensity thresholds for evaluation of GCM predictions. Applying these to ‘good’ and ‘poor’ Atmospheric Model Intercomparison Project (AMIP) simulations of the Murray Darling gives rise to large differences in rainfall amount (30% to 62%). Selecting only ‘good’ models shows a >150mm annual groundwater recharge loss in El Niño cf. La Niña climates. These isotopic techniques are applicable to future model scenarios of basin-scale hydrology, especially in difficult to simulate semi-arid basins.
Radionuclide migration at the Koongarra uranium deposit, Northern Australia – lessons from the Alligator Rivers analogue project
(Elsevier B. V., 2006) Payne, TE; Airey, PL
The Koongarra uranium deposit in Northern Australia provides a ‘natural analogue’ for processes that are of relevance for assessing the safety of radioactive waste disposal. In an international project extending over two decades, the Koongarra ore body was studied to increase the understanding of radionuclide migration and retention mechanisms that might occur in the vicinity of a geological repository. The research effort included extensive characterisation of the geological, hydrological and geochemical conditions at the site. Patterns of the distribution of radionuclides (predominantly members of the 238U decay chain, but also the rare isotopes 239Pu, 99Tc and 129I) were studied in both solid and groundwater phases. The project included detailed studies of uranium adsorption on mineral surfaces, and of subsequent processes that may lead to long-term uranium immobilisation. Numerous models for uranium migration were developed during the project. This paper provides a comprehensive review of the research at Koongarra, and assesses the value of the site for integrating the results of a complex series of laboratory, modelling and field studies. The insights gained from this review of the Koongarra project may assist in maximising the potential scientific benefit of future natural analogue studies. © 2006 Elsevier Ltd.
Radionuclide migration at the Koongarra uranium deposit, Northern Australia: lessons from the Alligator Rivers analogue project
(Elsevier, 2006-01) Payne, TE; Airey, PL
The Koongarra uranium deposit in Northern Australia provides a 'natural analogue' for processes that are of relevance for assessing the safety of radioactive waste disposal. In an international project extending over two decades, the Koongarra ore body was studied to increase the understanding of radionuclide migration and retention mechanisms that might occur in the vicinity of a geological repository. The research effort included extensive characterisation of the geological, hydrological and geochemical conditions at the site. Patterns of the distribution of radionuclides (predominantly members of the U-238 decay chain, but also the rare isotopes Pu-239, Tc-99 and I-129) were studied in both solid and groundwater phases. The project included detailed studies of uranium adsorption on mineral surfaces, and of subsequent processes that may lead to long-term uranium immobilisation. Numerous models for uranium migration were developed during the project. This paper provides a comprehensive review of the research at Koongarra, and assesses the value of the site for integrating the results of a complex series of laboratory, modelling and field studies. The insights gained from this review of the Koongarra project may assist in maximising the potential scientific benefit of future natural analogue studies. © 2006, Elsevier Ltd.
Radiotracer applications in Australia
(The Institution of Engineers Australia, 1994-05-01) Airey, PL; Charlton, JS
Radioisotopes tracers have been applied in Australia since the early 1950's to a wide range of industrial and environmental problems. A number of key projects are described, A development of a commercial service through the Tracerco Australasia joint venture is outlined. The challenges and opportunities facing tracer technology in the modern industrial era are examined.
Radiotracer applications: case studies from four continents
(International Atomic Energy Agency, 2015-01-01) Jung, SH; Bandeira, JV; Brisset, P; Wörman, A; Airey, PL; Hughes, CE
Case studies are a simple way to demonstrate how radiotracers can be successfully used in the environment in addressing water resources contaminant transport and coastal management issues. This paper presents ten case studies from Korea, France, Brazil, Hong Kong, Australia, Belgium and Sweden using a variety of radiotracers including 99mTc, 198Au, 3H, 82Br, 32P, 175+181Hf, 160Tb, 51Cr(III), 65Zn, 54Mn and 35S. These studies address physical transport processes such as dispersion and mixing, reactive transport and adsorption and contaminant uptake. Traced components include water, effluent, nutrients, contaminants and mud in rivers, lakes, wetlands and coastal waters.
Radiotracer methodology
(International Atomic Energy Agency, 2015-01-01) Brisset, P; Airey, PL; Jung, SH; Hughes, CE
Methods for the use of radiotracers in aquatic environments have been established over the past five decades. The basic principles involve definition of the system or problem to be investigated, selection of a suitable tracer, design of tracer deployment and measurement systems and analysis of the data collected to address the initial problem. These aspects are covered in detail in this paper covering the current state of the art in tracer technology. New developments in the use of nano-particle tracers are also addressed. © The authors.
Stable water isotopes as tools for basin-scale water cycle: diagnosis of the Murray–Darling
(Elsevier Ltd, 2006) Henderson-Sellers, A; Airey, PL; McGuffie, K; Stone, DJM
We examine the hypothesis that isotopic techniques are applicable to hydrological predictions in difficult-to-simulate semi-arid basins, using the Murray–Darling Basin as an example. Isotopic data from three aquifers in the Murray–Darling characterize precipitation intensity for evaluation of GCMs. Applying these to ‘good’ (water conserving) and ‘poor’ (non-water-conserving) climate model simulations of the Murray–Darling gives rise to large differences in rainfall amount (30–62%). Selecting only ‘good’ models shows a greater than 150 mm annual groundwater recharge loss in El Niño cf. La Niña climates. 2002–2003 El Niño drought data are used to refine isotopic calculation of water lost in evaporation from rivers and irrigation, giving a cumulative loss of 64% of river water during 2002 (cf. 80% using a previous method). This substantiates recent identification of this El Niño drought as evaporatively most extreme and we conclude that stable water isotopes, used synergistically with hydro-climate models, have great potential in future water resource predictions. © 2006 Elsevier B.V.
Sustainability of groundwater under climate change
(International Atomic Energy Agency, 2003-05-19) Airey, PL; Henderson-Sellers, A; Bradd, J; Chambers, SD; Hughes, CE; Habermehl, MA
One of the key commitments from the plan of implementation of the World Summit on Sustainable Development Johannesburg 2002 was to 'develop integrated water resources management and water efficiency plans by 2005'. In this paper, a detailed concept will be presented for assessing the sustainability of groundwater in warm arid and semi-arid areas challenged by climate change. The IAEA Global Network of Isotope Precipitation (GNIP) database is fundamental to the development of the concept which will be extended to the evaluation of climate change models. The concept will be evaluated with data from three recharge areas in the Great Artesian Basin, as well as aquifers in Central Australia, in the far north of the country and in Victoria. Experimental work is currently being extended to the Murray-Darling Basin. The role of the GNIP in the evaluation of climate change models is illustrated with data from the Amazon. Groundwater sustainability is achieved through balancing exploitation of the resource with recharge. As groundwater exploitation raises issues of demand management beyond the scope of this paper, the focus will be on recharge. Surface water infiltration is dependent on total rainfall within the intake areas, the seasonal distribution of rainfall, the rainfall intensity and the antecedent landscape conditions. Variation in total rainfall can be predicted without recourse to isotope data. However, effective recharge will only occur if the total monthly rainfall exceeds a threshold value. The above-mentioned concept involves predicting these threshold values from GNIP and groundwater isotope data. The evaluation of the concept with field data, and its incorporation into a predictive tool are the central themes of this paper. Four stages are involved: Stage 1: Correlating isotope depletion and the total monthly rainfall Analysis of the GNIP data from continental stations shows a widespread trend towards increasing stable isotope depletion with increasing monthly average rainfall. Stage 2: Matching stable isotope levels in groundwater with those in rainfall with monthly totals exceeding a threshold value The stable isotope levels in groundwater is generally depleted relative to that in mean average rainfall at recharge. The groundwater levels match those in rainfall provided the monthly intensity reaches a threshold value. This value, which may be expressed as a percentile of all monthly data for the GNIP station, is interpreted as the threshold value for effective recharge. The difference between the stable isotope ratios in groundwater and in the mean rainfall is called the 'groundwater depletion'. Stage 3: Correlating the 'groundwater depletion' with aridity. It will be shown with reference to data from Australian aquifers that the 'groundwater depletion' correlates with a defined 'aridity index'. Stage 4: Development of the predictive tool: The above mentioned correlation is the basis of a tool which may be applied to a) assessing groundwater sustainability, b) predicting soil moisture in the root zone and thus contribute to agricultural sustainability and c) evaluating climate change models. a) Groundwater sustainability: Climate change leads to variations in the 'aridity index' and hence to variations in the threshold intensity for effective recharge (Stage 3 above). Climate changes may be modelled numerically, assessed through correlations with sub-global parameters such as ENSO (El Nino Southern Oscillation) Index or simply postulated as scenarios. Reliable knowledge of predicted changes to effective recharge, would provide decision makers with additional time to adjust the groundwater exploitation rate consistent with the long term sustainability of the resource. b) Sustainability of the agricultural and pastoral industries: Variations in soil productivity depend on a number of factors including moisture levels in the root zone. Predictions of the soil moisture levels will depend on the temporal variation of the effective recharge (above), the water balance and the residence time distribution of the water. The use of isotopes to establish a water balance at a site in the Darling basin has been demonstrated. c) Evaluation of climate models: The use of isotopes to evaluate climate change models has been demonstrated in the Amazon basin. The principles will be extended to arid and semi arid areas using isotopic data in age dated groundwater as a probe for variations in effective recharge and therefore in the aridity index. The concept will be illustrated with data from the Great Artesian Basin and the Mereenie Sandstone aquifer in Central Australia. On-going project work will be focussed on ANSTO's contribution to the Murray-Darling Water Basin Study through the GEWEX (Global Energy and Water Cycle Experiment) Hydrometeorological Panel and the IAEA Coordinated Research Program Isotope Tracing of Hydrological Processes in Large River Basins, 2002-2004. The Organisation is also contributing to the Integrated Climate System Study (ICSYS) initiative of the IAEA/WCRP (World Climate Research Programme). © The authors.
Temporal analysis of stable water isotopic characteristics in the Murray Darling Basin
(International Atomic Energy Agency, 2004-10-24) Henderson-Sellers, A; Airey, PL; Stone, DJM; Bradd, J; McGuffie, K
“Water shortages, especially in tropical countries, are the climate challenge for this century” [1]. The isotopic composition of water and carbon in e.g. ice cores, ground water and biomass has been recognized as relevant to hydro-climates on timescales from glacial [2] to extreme weather [3]. We present Australian stable water isotope (SWI) research capability and exploit it in novel ways in order to establish objective validation of and improvement in existing water resource models ultimately reducing uncertainty in predictions. The use of stable water isotopes in hydro-climate modelling is refined on three timescales for the Murray Darling Basin. Isotopes demonstrate that in semi-arid regions, groundwater recharge occurs when the rainfall intensities exceed a threshold suggesting improvement of aquifer predictions over tens to thousands of years using isotopic threshold estimates. A range of atmospheric global circulation models ’ simulations of key hydrological parameters over years to decades reveals poor results for the majority (13 in 20) and underlines the value of isotopic constraints on basin hydrology. Modelling minute to monthly isotope fluxes using land surface schemes and a steady state (phenomenological) model of river hydrology allows comparison of the partitions of precipitation between transpiration, run-off and ‘lake’ evaporation with isotope observations from June 2002 to January 2003. These results will have the greatest importance if combined to improve the dynamics of simulations of regional water cycles [4]. Three timescales have been used here to explore the role of stable water isotopes in refining climate and hydrological models of the Murray Darling Basin. Firstly, over tens to thousands of years, we have examined the processes leading to the effective recharge of groundwater. The isotope data clearly indicate that in the warm arid/semi-arid regions, in contrast to the behaviour in cool temperate zones, effective recharge only occurs when the rainfall intensities exceed a threshold value. Isotopic estimates of this recharge threshold rainfall intensity could be applied to predictions of future groundwater resources. Secondly, over years to decades, we have assessed the success of a range of atmospheric global circulation models in simulating key hydrological parameters over the AMIP II period including El Niño and La Niña forcing. The results are rather poor for the majority (13 out of 20) GCMs suggesting that further constraints on the basin’s hydrology, such as from isotopes, may be valuable. In our third approach, we have modelled minute to monthly isotope fluxes using (a) land surface schemes (LSSs) at particular grid points within the Murray Darling Basin and (b) a steady state (phenomenological) model of river hydrology. Model conservation, climatic variations and ‘plausibility’, all pre-requisites for good simulations, have been investigated here for the Murray Darling. Models’ partitions of precipitation between transpiration, run-off and ‘lake’ evaporation are compared with isotope observations from the Darling River between June 2002 and January 2003. We find that: (i) more work is needed on gross water fluxes first; (ii) simple isotopic models generate plausible values but more complex ones, as yet, do not; and (iii) isotopes have potential for evaluation of whether LSSs are (in)correctly recharging and accessing groundwater reservoirs and for evaluation of the partitioning of water into runoff cf. re-evaporation. Tests based around these concepts offer a novel addition to the traditional methods of validating climate models and their sub-components.
Uranium adsorption and fixation processes at the Koongarra analogue site, Northern Australia
(Institut de Physique Nucleaire de Lyon, 2005-09-18) Payne, TE; Airey, PL
In an international project extending over two decades, the Koongarra uranium deposit in Northern Australia has been studied as a model of radionuclide migration processes that are of relevance to assessing the safety of radioactive waste repositories. The research effort has included detailed studies of uranium adsorption on mineral surfaces, and of subsequent processes that may lead to the long-term immobilisation of uranium. Similar processes are expected to be of significance in assessing the long-term behaviour of radionuclides in the vicinity of a radioactive waste repository. Uranium adsorption has been experimentally studied, and modelled, on various samples, including complex natural materials from the Koongarra ore body as well as simple model minerals (such as clays or iron oxides). In addition, considerable effort has been expended to compare laboratory and in-field uranium distribution data. The Koongarra deposit is believed to be one of the few field sites where this type of comparison has been attempted. This paper reviews the research at Koongarra and in particular focuses on the value of the natural analogue site for integrating the results of a complex series of laboratory, modelling and field studies. © The Authors
Using radiotracer techniques for coastal hydrodynamic model evaluation
(Elsevier Science Ltd., 2004) Hughes, CE; Airey, PL; Duran, EB; Miller, BM; Sombrito, E
A three-dimensional (313) water circulation and contaminant transport model of Manila Bay has been developed with the aim of better understanding the formation and movement of harmful algal blooms. Radiotracer techniques were used to evaluate the model by recording the dispersion of a tracer at depths of 2 and 15 m near the injection point. The selected tracer was Tc-99m eluted from a molybdenum/technetium medical generator. The rationale for the choice of the tracer and the location of the injection is discussed. At 2 m the transport was dominated by the prevailing winds, and at 15 m by tidally induced currents. The development of the hydrodynamic model and its experimental evaluation were iterative processes. The experimental study confirmed the need for full 3D modelling of Manila Bay; quantified the impact of the prevailing wind field on contaminant dispersion near the injection point; and allowed the calculation of transverse dispersivity to guide the selection of parameter values used in the overall model. Crown Copyright © 2004 Elsevier Ltd.

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