ANSTO's research reactor

Inside OPAL

OPAL's open pool design makes it easy to
see and manoeuvre items inside the reactor

See larger image

ANSTO's Open Pool Australian Lightwater (OPAL) reactor is a state-of-the-art
20 Megawatt reactor that uses low enriched uranium fuel and is cooled by water.

Opened by the Prime Minister in 2007, OPAL is one of a small number of reactors with
the capacity for the commercial production of radioisotopes. This capacity, combined with the open pool design and operating utility, places OPAL among the best research reactors in the world.  

While OPAL is the centrepiece of ANSTO's research facilities, the suite of neutron beam instruments housed next to the reactor building represent a significant addition to ANSTO's research capabilities.

These facilities, operated by the Bragg Institute, are supported by the Minister for Innovation, Industry, Science and Research, Senator Kim Carr, who recently described ANSTO's contribution to Australian science by saying:
"Having started out as a specialist organisation tied to this site at Lucas Heights, ANSTO is now driving innovation in nuclear science and technology right around the country. The Government is very aware of how important this work is."

The role of research reactors

While virtually every reactor is unique, OPAL is one of a number of similar production facilities around the world, including the Safari-1 reactor in South Africa, the HFR reactor
at Petten in the Netherlands and the NRU reactor at Chalk River in Canada. These
reactors play a vital role in society by helping us understand the world at the atomic level. They function as 'neutron factories' producing isotopes for several important purposes, including the production of radioisotopes for cancer detection and treatment.

OPAL Reactor Ops

OPAL Reactor Operations - control room

OPAL's operation staff cooperate with their international colleagues in sharing information and knowledge both directly through formal collaboration agreements and via various international organisations and forums.

OPAL user groups

OPAL is used by members of the scientific, medical, environmental, industrial and security communities, as well as Australian universities.

While OPAL is extremely versatile, and the uses of neutron science are virtually unlimited, OPAL's main uses are:

  • Irradiation of target materials to produce radioisotopes for medical and industrial applications
  • Research in the field of materials science using neutron beams and associated instruments
  • Analysis of minerals and samples using neutron activation techniques - and delayed neutron activation techniques
  • Irradiation of silicon ingots (termed Neutron Transmission Doping or NTP) for use in the manufacture of electronic semiconductor devices.

Operation cycle

OPAL is operated in cycles typically of 4-5 weeks in length and is manned 24 hours a day, 365 days a year. The reactor is shutdown for routine maintenance and refuelling at the end of each operating cycle, typically for a few days.

Inside OPAL

The heart of the reactor is a compact core of 16 fuel assemblies arranged in a 4x4 array, with five control rods controlling the reactor power. OPAL uses low enriched uranium fuel with just under 20 per cent uranium-235. In terms of security and nuclear safeguards, this is a distinct advantage over earlier research reactors; some of which required as much as 95 per cent enriched uranium (weapons grade).

OPAL's fuel assemblies are cooled by demineralised light water (ordinary water) and are surrounded by a zirconium alloy 'reflector' vessel which contains heavy water. It is positioned at the bottom of a 13-metre-deep pool of light water. The open pool design makes it ease to see and manipulate items inside the reactor pool. The depth of the water ensures effective radiation shielding of staff working above the pool.