High Flux Australian Reactor

The High Flux Australian Reactor (HIFAR) was Australia's first nuclear reactor. It was built at the Australian Atomic Energy Commission (later ANSTO) Research Establishment at Lucas Heights.

Based on the DIDO reactor at Harwell in the UK, HIFAR was cooled and moderated by heavy water, and the fuel was enriched uranium. There was also a graphite neutron reflector surrounding the core. Like DIDO, its original purpose was nuclear materials testing, using its high neutron flux to give materials intended for use in nuclear power reactors their entire expected lifetime neutron exposure in a relatively short period.

HIFAR was used for research, particularly neutron diffraction experiments, production of neutron transmutation doped (NTD) silicon, and for production of medical and industrial radioisotopes.

HIFAR went critical at 11:15 pm local time on 26 January 1958, and was first run at full power of 10MW (thermal) in 1960. The initial fuel was highly enriched uranium, but over the years the enrichment level of new fuel was steadily reduced, in line with international trends designed to reduce the danger of diversion of research reactor fuel for weapons programs. HIFAR completed conversion to low enriched uranium fuel (LEU) in 2006. Of the six DIDO class reactors built including DIDO itself, HIFAR was the last to cease operation. Permanent decommissioning of HIFAR commenced on 30 January 2007 and is expected to be completed by 2025.