Keywords: routine atmospheric dispersion modelling, emergency atmospheric dispersion modelling, model evaluation, environmental gamma monitoring data, puff, PC-Cream, tracer datasets, nuclear reactors, air quality, air pollution, radionuclides, radiological dispersion
Nuclear tools for characterising radiological dispersion in complex terrain: evaluation of regulatory and emergency response models
Routine operations of a nuclear research reactor and its facilities offer opportunities for collection of rare environmental tracer datasets which can be used for atmospheric dispersion model evaluation studies. The HIFAR reactor near Sydney, Australia, routinely emits the radioactive noble gas 41Ar, and other radionuclides such as 133Xe and 135Xe are also emitted from nearby radiopharmaceutical production facilities. Despite extremely low emission levels of these gases, they are nevertheless detectable using state-of-the-art technology, and sensitive detectors have been placed at four locations in the surrounding region which features complex terrain. The high research potential of this unique dataset is illustrated in the current study, in which predictions from two atmospheric dispersion models used for emergency response are compared with 41Ar peak observations from the detector network under a range of stability conditions, and long-term integrated data is also compared with a routine impact assessment model.