ANSTO begins decommissioning Australia's first reactor

Tuesday, 4 March 2025

The 10 MWt reactor's full name is the High Flux Australian Reactor, but it is usually known as HIFAR. Located at Lucas Heights, near Sydney, ANSTO - Australia's nuclear science and technology organisation - is the reactor's licensed owner and former operator.

ANSTO CEO Shaun Jenkinson said the commissioning of the reactor in 1958 had formally ushered in Australia's nuclear age, with its distinctive white circular steel frame forming a prominent south Sydney landmark for nearly 70 years. "As a multi-purpose 10 megawatt reactor, HIFAR pioneered Australia's nuclear medicine production and silicon irradiation capabilities, and housed the first neutron beam research instruments - all of which paved the way for the sovereign capabilities we have here at ANSTO today," he said.

The reactor's fuel and heavy water coolant were removed within a year of its closure. In 2023, ANSTO submitted a licence application to Australia's nuclear regulator ARPANSA to begin early stages of decommissioning. After review, public consultation and assessment, ARPANSA gave its approval for the start of limited decommissioning in December 2024.

ANSTO Senior Project Manager Brett Wheeler said it had taken 10 years of planning and preparations ahead of ARPANSA's licence approval. "The job at hand for now is to remove only the internal infrastructure and radioactive components inside the 21-metre-tall facility," he said, adding that there are no plans to dismantle the exterior structure - including HIFAR's iconic white exterior shell - until later.

"A driving factor in starting the decommissioning work was to take advantage of the collective knowledge of the HIFAR team, many of whom are now approaching retirement," he said. "So it’ll be a fitting send-off for the decades spent working with such an iconic piece of Australia's scientific and engineering history.”

The first stage of Phase A of the decommissioning project is expected to be completed by 2026 and will include the removal of the six neutron beam instruments, two fuel flasks, rig support equipment, silicon storage blocks, the fuel assembly station, general utilisation equipment, and the control room. The next two Phase A stages and Phase B, which will include the decommissioning of the reactor core, will require additional approvals from ARPANSA.

Most of the waste generated from Phase A decommissioning will be solid waste that can be safely recycled after final characterisation, ANSTO said. The small quantity of radiological waste will be managed and stored safely onsite at Lucas Heights in existing purpose-built facilities, while any hazardous (non-radiological) waste, such as lead and lead-based paints, will be disposed of offsite at a purpose-built facility. 

Construction of HIFAR commenced in 1955, and the reactor went critical in January 1958. It was officially unveiled by Australian Prime Minister Robert Menzies in April that year. It was superseded by ANSTO's OPAL multi-purpose research reactor in 2006 and officially shut down by then-Federal Science Minister Julie Bishop in January 2007.