ANSTO has safely and responsibly managed spent nuclear fuel and its resulting radioactive waste from its three nuclear research reactors (HIFAR, Moata, and OPAL) since the 1950s.
The multi-purpose research reactor OPAL, is one of a small number of reactors around the world with the capacity to produce commercial quantities of radioisotopes commonly used in lifesaving nuclear medicines to detect and treat diseases such as cancer. Millions of patient doses of the most widely-used nuclear medicine in the world, Molybdenum-99, have been produced onsite at ANSTO.
OPAL operates on an array of nuclear fuel rods containing low-enriched uranium-235, which enables nuclear fission to take place in the reactor. These rods need to be replenished every few months with fresh fuel rods once they are ‘spent’ or reach the end of their useful life.
The management of spent fuel encompasses how it is stored, transported, and re-processed. ANSTO’s spent fuel is not classified as radioactive waste until the point that it can be reprocessed overseas, and the resulting waste is returned to Australia.
Spent fuel management
ANSTO’s spent fuel is securely and routinely sent overseas for reprocessing with our global partners. ANSTO has undertaken 10 international shipments of spent fuel from the HIFAR and OPAL research reactors. The last shipment of spent fuel was carried out in 2018.
To prepare for a spent fuel shipment, all spent fuel rods are placed together in secure storage pool areas to dissipate the heat from fission reactions in the reactor core.
From here, the spent fuel rods are carefully loaded into specially designed, purpose-built casks that provide heavy shielding during transportation by road and sea. These casks meet the most stringent standards set by the IAEA.
The spent fuel is then shipped overseas to partners in the UK, France, or the US where they undergo reprocessing. During this process, any residual materials such as uranium are extracted and recycled for use in the other country’s nuclear power programs and for other peaceful purposes.
The remaining material is broken up and mixed in with molten glass through a process called vitrification. This process safely immobilises the resulting waste into sealed, stainless-steel canisters for long-term storage until they can be returned to Australia. Each stainless-steel canister weights around 500 kilograms when full.
Repatriation of waste to Australia
ANSTO has facilitated two repatriation projects for the return of re-processed waste to Australia. The first shipment to Australia from France occurred in 2015, which saw the return of the resulting radioactive waste from ANSTO’s four spent fuel shipments sent to France between 1999 and 2004.
The most recent repatriation of waste was sent from the UK in 2022 and is the resulting waste of a spent fuel shipment sent to the UK in 1996.
In both repatriations, the waste returned to Australia was transported in forged steel transport and storage casks called a TN-81.
These 100 tonne casks house the stainless-steel canisters of vitrified waste, and measure 6.5 metres long and 3 metres wide. They are heavily shielded for safety and protection during transportation and long-term storage, and are widely used in Europe for transport and storage of radioactive waste.
In total, ANSTO has two TN-81 casks in interim storage at its intermediate-level waste facility in Lucas Heights.