OPAL Reactor

The OPAL (Open Pool Australian Light-water) Reactor is Australia's only operating nuclear reactor, located at the Australian Nuclear Science and Technology Organisation (ANSTO) campus at Lucas Heights in southern Sydney. OPAL was commissioned in 2006, replacing the older HIFAR (High Flux Australian Reactor) reactor that operated from 1958 to 2007.

Key aspects of the OPAL Reactor:

1. Technical specifications:

• Type: Open pool, light-water moderated and cooled research reactor
• Power: 20 MW thermal
• Fuel: Low-enriched uranium (LEU) plate fuel — using uranium silicide (U3Si2) fuel with enrichment below 20% U-235
• Moderator/coolant: Light water (H2O)
• Reflector: Heavy water (D2O) surrounding the core for enhanced neutron efficiency
• Design: Open pool design allows easy access to the core and irradiation facilities
• Supplier: Designed and built by INVAP (Argentina) with Australian industry participation

2. Nuclear medicine production:

• OPAL produces approximately 80% of Australia's nuclear medicine supply
• The primary product is technetium-99m (Tc-99m), the most widely used medical radioisotope for diagnostic imaging
• Tc-99m is produced by irradiating uranium targets in the reactor, then processing the irradiated targets in ANSTO's hot cells
• OPAL's nuclear medicine production demonstrates the peaceful applications of nuclear technology and ANSTO's contribution to healthcare
• ANSTO exports nuclear medicine to regional partners in the Asia-Pacific

3. Neutron beam research:

• OPAL's neutron beams are used for materials science, structural biology, and engineering research
• The reactor has multiple neutron beam instruments including diffractometers, spectrometers, and imaging facilities
• Australian and international researchers use OPAL's neutron beams for a wide range of scientific applications
• Neutron beam research at OPAL contributes to materials development for defense, energy, and healthcare applications

4. Irradiation services:

• OPAL provides neutron irradiation services for various applications including:
  • Silicon doping for semiconductor manufacturing
  • Radioisotope production for industrial and medical applications
  • Neutron activation analysis for materials characterization
  • Radiation hardness testing for electronics

5. AUKUS connection:

• OPAL provides critical nuclear expertise for Australia's AUKUS nuclear submarine program
• The reactor's operation builds Australian nuclear regulatory, safety, and operational experience
• ANSTO's experience with OPAL informs the Australian Naval Nuclear Power Safety framework
• OPAL-trained nuclear engineers and operators provide a workforce foundation for the nuclear submarine program
• While OPAL is a research reactor (not a propulsion reactor), the nuclear expertise from its operation is directly relevant to naval nuclear propulsion

6. Safety and regulation:

• OPAL is regulated by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA)
• The reactor operates under strict safety protocols and international safeguards (IAEA)
• OPAL has a strong safety record since commissioning in 2006
• The regulatory framework for OPAL provides a model for the Australian Naval Nuclear Power Safety framework

7. Historical context:

• OPAL replaced the HIFAR reactor, which operated from 1958 to 2007
• HIFAR was a 10 MW DIDO-class research reactor, one of several built worldwide in the 1950s-60s
• The transition from HIFAR to OPAL represented a significant upgrade in Australia's nuclear research capability
• The decision to build OPAL reflected Australia's commitment to maintaining nuclear research capability for medical, scientific, and strategic purposes

The OPAL Reactor is a critical national facility that provides Australia with nuclear research capability, nuclear medicine production, and the nuclear expertise foundation for the AUKUS nuclear submarine program. As Australia's only operating nuclear reactor, OPAL is irreplaceable for Australian nuclear science and technology. The reactor's contribution to nuclear medicine (80% of Australia's supply) demonstrates the peaceful benefits of nuclear technology, while its role in building nuclear expertise supports the strategic AUKUS submarine program.