Investigate how technological developments have enhanced scientific research, including a research facility such as a nuclear reactor or synchrotron

What this dot point is asking

NESA wants you to describe how a large-scale research facility enables scientific research that would otherwise be impossible, with a specific case study. The OPAL reactor at ANSTO is the recommended Australian example.

The answer

OPAL (Open Pool Australian Lightwater reactor) is Australia's national nuclear research reactor. Operated by ANSTO at Lucas Heights in southern Sydney since 2007, it produces nuclear medicine isotopes and provides neutron beams for materials research.

What OPAL is

OPAL is a 20 MW reactor that uses low-enriched uranium fuel (less than 20 per cent U-235, well below weapons-grade) cooled by light water. It replaced the older HIFAR reactor in 2007 and is one of about 50 research reactors operating worldwide. Importantly, OPAL is not a power reactor: it does not generate electricity. Its purpose is to produce neutrons.

What neutrons can do

Neutrons are neutral subatomic particles produced in the reactor's core. Two main uses:

1. Probing materials with neutron beams.

Unlike X-rays, neutrons pass through dense materials, are scattered by light elements like hydrogen and reveal atomic positions, magnetic moments and atomic vibrations. Eight neutron-beam instruments at OPAL serve fields from drug design to battery research.

Specific instruments at OPAL include:

• WOMBAT. A high-intensity diffractometer for fast atomic structure determination.
• KOWARI. A residual stress diffractometer used for engineering components and welds.
• PELICAN. Time-of-flight spectrometer for dynamics of magnetic and quantum materials.
• PLATYPUS. Reflectometer for thin films and interfaces.

2. Transmuting targets to produce radioisotopes.

Materials placed in the reactor are bombarded with neutrons, which converts stable isotopes into useful radioisotopes.

Nuclear medicine production

OPAL is the only Australian source of medical radioisotopes.

Technetium-99m alone is used in 80 per cent of all nuclear medicine procedures globally. About 700,000 scans per year in Australia depend on OPAL.

Other applications

Silicon transmutation doping

Pure silicon ingots are irradiated to convert a small fraction to phosphorus, producing semiconductor-grade silicon used in high-voltage electronics for solar arrays and electric vehicles. OPAL is one of the world's largest commercial doping services.

Neutron activation analysis

Trace elements can be detected at parts-per-billion sensitivity by activating samples and measuring the gamma rays emitted. Used for forensic science, archaeology and environmental monitoring.

Indigenous artefact analysis

Researchers have used OPAL's neutron techniques to study Aboriginal ochre samples and stone tools, identifying trade routes and pigment sources across the continent.

Scientific output

About 700 visiting scientists from Australian and international universities use OPAL's beam instruments each year. Output includes:

• Lithium-ion battery materials. Neutron diffraction of cathode materials at the University of Wollongong and ARC Centres of Excellence.
• Mining waste characterisation. Neutron techniques for tracking heavy-metal contamination.
• Pharmaceutical research. Drug crystal structure determination.
• Climate science. Ice-core dating using neutron activation.

Strategic and policy context

ANSTO's OPAL gives Australia:

• Independence from overseas supply of molybdenum-99. The Canadian NRU reactor (a major global supplier) shut down in 2018, causing global shortages. OPAL has helped stabilise supply.
• A neutron-science capability that universities cannot afford to build individually.
• A national nuclear science training facility.

Controversies

• Safety. OPAL is licensed by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) and operates to international Atomic Energy Agency (IAEA) safeguards.
• Waste. Spent fuel is sent to France for reprocessing under a long-term agreement; intermediate-level waste remains at Lucas Heights pending a National Radioactive Waste Management Facility, which has been politically contested.
• Cost. OPAL cost approximately 400 million AUD to build, and ANSTO's annual budget is around 250 million AUD per year. Critics argue the cost is high relative to other research-funding options; supporters cite the irreplaceable medical isotope supply.

Examples in context

Example 1. OPAL technetium-99m supply during shutdowns. When OPAL underwent a planned three-month maintenance shutdown in 2018, ANSTO arranged molybdenum-99 imports from South Africa's SAFARI reactor and from Belgium's BR2 to maintain hospital supply. Hospital nuclear-medicine departments scheduled non-urgent scans around the shutdown, and the Commonwealth Department of Health temporarily expanded import licences. The episode exposed the global fragility of medical-isotope supply: only a small number of research reactors worldwide produce Mo-99, and unplanned outages at any one of them ripple through hospital schedules across continents. The case illustrates why governments treat OPAL as critical national infrastructure rather than as ordinary research equipment.

Example 2. OPAL neutron beam structural biology. The Australian Centre for Neutron Scattering at OPAL operates several beam-lines that biologists use to study proteins in their natural hydrated state, because neutrons (unlike X-rays) interact strongly with hydrogen and weakly damage biological samples. A 2023 study by Monash University researchers used the SANS instrument at OPAL to map structural changes in spider-silk proteins under tension, work that informed bio-inspired material design. Beam time is awarded by peer-reviewed proposal, with about 60 per cent of proposals from non-Australian researchers. The case shows that research facilities with no commercial output (neutron beams) enable scientific work that no other Australian instrument could perform.

Try this

Q1. Explain how OPAL produces technetium-99m for medical imaging. [3 marks]

• Cue. Neutron bombardment of uranium-235 produces molybdenum-99; Mo-99 decays (half-life 66 h) to Tc-99m which emits a clean gamma ray suitable for SPECT imaging.

Q2. A proposal to replace OPAL's Mo-99 production with cyclotron-produced Tc-99m is debated. Discuss one advantage and one limitation of the cyclotron approach. [3 marks]

• Cue. Advantage: no nuclear waste, smaller facility footprint. Limitation: lower yield per unit cost, distribution constrained by Tc-99m half-life (6 hours), requires many small cyclotrons rather than one reactor.

Q3. ANSTO holds public consultation about expanded waste storage at Lucas Heights. (a) Identify one ethical consideration. (b) Identify one piece of primary data the consultation might collect. (c) Identify one ARPANSA role in the process. [2+2+2 marks]

• Cue. (a) Intergenerational fairness; consent of nearby communities including Aboriginal stakeholders. (b) Submissions, public-meeting transcripts, survey responses. (c) Independent licensing and inspection; verification of radiation-protection standards.