In response to the requirement for a more compact and portable atmospheric radon-222 monitor with calibration traceability to the International System of Units, the team undertook the development of a 200-litre radon monitor to fulfil these specific needs.
The dual-flow-loop two-filter ANSTO technology, which is considered a world-leading innovation, has been deployed in over 30 locations globally. However, the demand for this technology is steadily increasing due to the growing importance of gaining a deeper understanding of the mechanisms behind urban air pollution and climate.
Acknowledged by the World Meteorological Organization as the foremost technology for conducting comprehensive global and atmospheric compositional baseline studies, this technology is widely regarded as the best in the world. It is extensively employed by prominent environmental monitoring organisations and the International Atomic Energy Agency to advance their research and analysis capabilities.
The radon monitors designed by ANSTO, manufactured and maintained by a team of dedicated environmental scientists, play a crucial role in providing invaluable data on atmospheric mixing. These monitors enable accurate monitoring of dynamic atmospheric conditions, thereby supporting the understanding and assessment of changes occurring in the atmosphere.
According to Dr Scott Chambers, an environmental Atmospheric Physicist and Senior Researcher, the team became aware of a competitor’s product that, although less sensitive, offered greater portability. This discovery served as a catalyst for their own efforts to explore possibilities of reducing the size of their product.
Funding support was received from the National Metrology Institute in Germany, which expressed interest in acquiring one of the new detectors for an international Trace Radon Project. Encouraged by this support, the team proceeded with their development efforts.
The key modification involved reducing the volume of the main measurement chamber from 1500 litres to 200 litres. Despite this significant change, the newly developed monitor retained its ability to accurately measure radon activity levels as low as 0.14 Becquerels per cubic meter, ensuring reliable and precise measurements.
In the smaller volume of air, there are essentially fewer alpha particles and decay products to be counted, but for most purposes, the results are still deemed highly satisfactory. Efforts are currently underway to enhance the sensitivity by implementing modifications to the measurement head.
The reduced size of the new detector will make it highly suitable for monitoring radon concentrations in buildings, where environmental authorities aim to ensure safety due to the potentially harmful effects of radon. Establishing baseline data is crucial for making accurate assessments. Furthermore, the new detector is designed to be more manageable, as it can be divided into two parts and easily accommodated in a regular vehicle, weighing less than 80 kilograms in total.
The smaller models of these instruments will offer the added advantage of being calibrated with much greater accuracy in the field compared to their larger counterparts.
The technology proves to be highly valuable in environments where prompt and precise monitoring of even relatively low levels of radioactivity is necessary. It finds particular utility in urban pollution studies, as well as in buildings and underground science facilities like the Stawell Underground Physics Laboratory.
In the Northern Hemisphere, the emissions of naturally occurring radon from the ground pose a greater concern, mainly due to building insulation practices that tend to trap the gas.
Notably, the UK has recorded instances of exceptionally high radon levels.
The instrument is constructed using marine-grade stainless steel, ensuring its durability for a service life of over ten years. With the exception of periodic pressure checks, it can operate autonomously with minimal maintenance for extended periods of time. In comparison to other scientific instruments, this level of maintenance is exceptionally minimal.
Currently, ANSTO technician Mr Ot Sisoutham is responsible for assembling the detectors. However, ANSTO is in the process of negotiating external production to meet the growing demand for these instruments.
ANSTO engages in various activities to monitor contaminants that traverse the atmosphere and impact the surrounding ecosystems, including the environmental monitoring of radon.
