Equipment being installed in ANSTO's Synroc radioactive waste processing facility

Thursday, 20 October 2022

The Synroc ("Synthetic Rock") facility will treat intermediate-level liquid radioactive waste from the production of nuclear medicine by immobilising the waste in a highly durable solid wasteform for final disposal. Synroc is an Australian innovation based on crystalline or mineral phases that have survived in natural geological environments at elevated temperatures in the presence of water for hundreds of millions of years.

In the Synroc process, the radioactive liquid waste is first mixed with additives that create a slurry that is then dried to produce a free-flowing powder. The granular powder is thermally treated before it is dispensed into cans where it is sealed. The can is then placed inside a furnace that is contained within a hot isostatic press (HIP), where heat and pressure are applied to lock in the radionuclides. Under these conditions the powdered mixture fuses together to form a solid without releasing any emissions. The can contracts to form a cylindrical shape which is designed for storage efficiency.

Although Australia does not have any nuclear power plants, it has a sizeable nuclear medicine industry with ANSTO producing 12,000 doses each week for patients, as well as exporting more.

ANSTO says there is growing international interest in the Synroc technology. 

"Along with the benefits of a nuclear medicine production comes a responsibility to safely manage the by-product radioactive waste. That’s what our waste treatment technology has been designed to achieve," said ANSTO’s Synroc Technologies Technical Director Gerry Triani.

"Synroc is an innovative, safe and effective radioactive waste treatment technology which can be built into nuclear supply chains anywhere in the world," he added.

The building is now being fitted with the equipment for the Synroc process, "designed for remote operations inside a shielded hot-cell environment".

A full-scale demonstration Synroc plant has been operating for the past five years, showing, ANSTO says, that the technology offers a "safe and efficient means of treating their waste in a disposal ready product".