Radionuclide migration at the Koongarra uranium deposit, Northern Australia: lessons from the Alligator Rivers analogue project.

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

The future of radiotracing

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.International Atomic Energy Agenc

Radiotracer methodology

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.International Atomic Energy Agenc

Using radiotracer techniques for coastal hydrodynamic model evaluation

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. © 2004 Elsevier Ltd

Dating, mass spectrometry and nuclear science: a proposed new facility at Lucas Heights.

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

Radiotracer applications: case studies from four continents

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.International Atomic Energy Agenc

Evolving role of radiotracers in coastal zone studies

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. © 2003, Elsevier Ltd

ANSTO's radioactive waste management policy: preliminary environmental review.

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