Scientists from the Australian Nuclear Science and Technology Organisation (ANSTO) are applying their expertise to help Asian authorities predict water and sediment flow and better manage their ports and estuaries.
Using isotopes to track the movement of sediments in the environment is one of the lesser known applications of nuclear technology.
Australian experts recently collaborated with colleagues from the Office of Atomic Energy for Peace in Thailand to trace siltation at the Port of Songhkla, which was causing a significant economic problem to the shipping industry. As part of the study, artificial glass sand incorporating a slightly radioactive element, Iridium-192 (known as a radiotracer), was released near the channels.
Scientists traced the radioactivity in the artificial sand over many months to check whether the predictions of the model developed by the University of New South Wales Water Research Laboratory were correct. The level of radioactivity was so low that it did not harm any aspect of the environment.
Dr Cath Hughes of ANSTO Environment said that the movement of radiotracers in the Port of Songhkla showed a close correlation with what was predicted.
"The results of the project gave local authorities confidence in their model, giving them the chance to plan port developments," she said.
ANSTO expertise has also been used in Manila Bay, in the Philippines, where red tides of toxic algal blooms have caused risk to human health and a major economic problem to the fishing industry.
An investigation was undertaken of the sources and transport of nutrients in the Bay, and a three-dimensional model developed by the University of NSW Water Research Laboratory. This model was calibrated using radiotracer techniques by the Philippines Nuclear Research Institute and ANSTO using a technetium- 99m tracer, a rapidly decaying isotope more commonly associated with medical procedures.
"The overall aim of the study was to contribute to the much wider challenge of minimising the frequency of occurrence of harmful algal blooms," Dr Hughes said. "The tracer data greatly enhanced the quality of the modelling by providing direct measurements of dispersion both on the surface and at depth under the influence of a wind field."