ANSTO has developed a comprehensive program to characterise the Intermediate Level Liquid Waste (ILLW) that is formed during the production of molybdenum-99. This program is an essential part of the quality assurance framework for the new ANSTO Synroc® Waste Treatment Plant. The expertise in characterising radioactive waste has been instrumental in supporting the development of this new plant.
"The ILLW produced as a by-product of molybdenum-99 manufacturing is processed into a safe disposal-ready solid waste form and encapsulated in a stainless-steel canister at the new plant at Lucas Heights. Waste characterisation ensures that the Synroc waste form meets the required specifications for storage and disposal," said Dr Daniel Gregg, who is the manager of the wasteform engineering team of ANSTO Synroc®.
"It is also in line with ANSTO's sustainability vision for managing its waste."
ANSTO Synroc® scientist Dr Anton Peristyy led the development of the analytical and radiochemical methods for the ILLW characterisation. These methods allow the measurement of the chemical and radiological composition of the ILLW with the accuracy required to inform the treatment process and to quality-assure the waste form produced in the facility.
The characterisation methods were transferred to specialised Waste Management Services Laboratories where they were implemented by Waste Characterisation Manager Dr Mark Ashford, and his characterisation team.
Following a detailed safety assessment of sampling and handling requirements of the active ILLW samples by both Waste Management Services and the Nuclear Medicine group, regulatory approval was granted to undertake ILLW sampling, transport and characterisation.
Waste characterisation is now ongoing at the Waste Management Services Laboratories allowing verification and refinement of the chemical and radiological properties of the waste. This approach is used to monitor the properties of ILLW as it is generated and will be applied to other radioactive waste streams that exist at ANSTO.
This challenging program has only been successful due to the willing collaboration of ANSTO Synroc®., Waste Management Services and the Nuclear Medicine group, including essential support from various enabling services across the organisation.
The first working plant of its type, the new ANSTO Synroc® Waste Treatment Plant, is currently in the cold commissioning phase at Lucas Heights.
