The Environmental Radioactivity Measurement Centre located on the main campus of the Australian Nuclear Science and Technology Organisation (ANSTO) at Lucas Heights is built from material with ultra-low background radiation levels.
The use of such building materials is unique allowing scientists to drill down further in their research to detect tiny amounts of radioactive material that would normally be drowned in background radiation in a regular laboratory
Federal Science and Research Minister Chris Evans who was on hand at the opening of the centre said this building would help scientists get their hands on even more refined data to better understand some of the world's most pressing environmental issues.
"These readings will enhance scientists' understanding of the environment in everything from algal blooms to deforestation and the frequency of bushfires," Senator Evans said.
The trick with this building project though was that we live in a world full of radiation. Sourcing building materials with extremely low background radiation levels is very challenging as everyday materials such as concrete can easily contain up to 100 becquerels per kilogram of uranium and thorium isotopes and 500-1000 becquerels per kilogram of potassium-40.
ANSTO’s Nuclear Methods in Earth Systems team, headed by Professor Henk Heijnis, led the way on the sourcing project undertaking detailed studies to find the best materials for the job.
The team looked at everything from floor tiles and ceiling tiles to wall materials and steel. The research informed the selection of materials and led to the development of a one-of-a-kind concrete, made from materials identified as having the lowest possible levels of radioactivity in Australia.
“As far as we know, this is a one-of-a-kind building in Australia.
"No other building has been developed with such a detailed study into its building materials to ensure every material has the lowest possible levels of background radiation,” Dr Heijnis said.
Central to the new building is a basement Gamma Spectrometry Control room, nicknamed ‘The Bunker’, which houses five gamma spectrometers. The Bunker is enclosed by a 550kg pre-World War II steel door and 30 centimetre thick low radioactive concrete ceiling, floor and walls.
The new building also features a range of specialised radiochemistry and environmental monitoring labs, a drying and combustion room, cold room, sample preparation room, workshop, garage and offices.
ANSTO’s Nuclear Methods in Earth Systems team leader Professor Henk Heijnis provides some insight into background radiation levels for the new Environmental Radioactivity Measurement Centre. He says everyday materials such as concrete can easily contain up to 100 becquerels per kilogram of uranium and thorium isotopes and 500-1000 becquerels per kilogram of potassium-40.
Designed to the highest OHS standards following input from ANSTO’s Safety, Environmental and Radiological Assurance (SERA) team, and with a range of ‘green’ environmentally friendly features, the Centre will be used as a benchmark for the design of new buildings at ANSTO.
Safety wise, the building includes one of ANSTO’s first ventilated cabinets, ensuring staff are not subject to chemical fumes; an industrial strength goods lift (dumb waiter) to reduce manual handling; and spacious labs to reduce accidents when used by multiple people.
“OHS wise it’s a dream. We’ve come from extremely old laboratories, at the end of their working life, into state-ofthe-art laboratories with facilities and equipment we could only have dreamed of a few years ago,” said Professor Heijnis.
Appropriately, the building is environmentally friendly with large external windows to take advantage of natural light; two 35,000 litre underground rain water tanks; a solar hot water system; and aluminium sun shades.
The roof features two layers of colorbond with a special insulation between to reduce heating and cooling costs.
The Centre will also play host to visitors on site tours, something not possible in the group’s old labs that was located behind security fences. Visitors can look through large lab windows from the corridors and view scientists at work with minimal disturbance and optimal safety.
A special mix
The concrete used in 'The Bunker' walls was developed by the ANSTO Nuclear Methods in Earth Systems group.
The team spent months testing different concrete mixtures made up of materials from across Australia before they settled on cement from Gladstone in Queensland and, fine sand and gravel from Cowra in New South Wales.
Standard Sydney concrete mix adds up to around 100 becquerels per kilogram for uranium and thorium isotopes and 500-1000 becquerels per kilogram of potassium. The concrete mixture created by the ANSTO team brought the uranium and thorium levels down to less than 10 becquerels per kilogram and the potassium-40 levels to about 20 becquerels per kilogram.
New core sediment and tree ring instrument
Complementing the innovative design of the building is state-of-the-art equipment including a scanner that can reconstruct the environmental and climate history of an area by analysing sediment cores and tree ring samples.
Environmental scientists will be utilising the ITRAX Corescanner to help better understand the history of earth's climate.
The ITRAX Corescanner takes extremely high resolution colour images – line by line – every 0.2 millimetres. These pictures are combined to provide a whole image of the sample. The instrument then takes the same number of x-rays of the sample at the same resolution. It also analyses the material at the same resolution for a range of elements using the XRF (X-ray Fluorescence) technique.
ITRAX will dramatically improve the efficiency of work done by our scientists ensuring samples are now kept intact and not destroyed. It will also speed up the measuring time so up to 10,000 measurements can be taken in only a few hours as opposed to a few weeks.
The instrument was purchased in a joint project between ANSTO, AINSE and a number of universities across Australia. Usage time on the instrument will be allocated by the AINSE committee.
Published: 24/04/2012