The Open-pool Australian lightwater reactor (OPAL) is a 20 megawatt (MW) swimming pool nuclear research reactor. Officially opened in April 2007, it replaced the High Flux Australian Reactor as Australia's only nuclear reactor, and is located at the Australian Nuclear Science and Technology Organisation (ANSTO) Research Establishment in Lucas Heights, New South Wales, a suburb of Sydney. Both OPAL and its predecessor have been commonly known simply as the Lucas Heights reactor.
The main reactor uses are:
The reactor runs on an operation cycle of 30 days non-stop at full power, followed by a stop of 5 days to reshuffle the fuel.
Typically the reactor runs for a total of some 300 days at power per year.
The Argentine company INVAP was fully responsible through a turnkey contract, signed in June 2000, for the delivery of the reactor, performing the design, construction and commissioning. Local civil construction was performed by INVAP's partner, John Holland-Evans Deakin Industries.[1] The facility features a large (20-litre (4.4 imp gal; 5.3 US gal)) liquid-deuterium cold neutron source,[2] modern supermirror guides, and a 35 by 65 metres (115 ft × 213 ft) guide hall. The cold source was designed by the Petersburg Nuclear Physics Institute,[3] the cryogenic system designed and supplied by Air Liquide and the initial set of four supermirror guides supplied by Mirrotron.[4]
On 17 December 2001, 46 Greenpeace activists occupied the Lucas Heights facility to protest the construction of OPAL. Protestors gained access to the grounds, the HIFAR reactor, the high-level radioactive waste store and the radio tower. Their protest highlighted the security and environmental risks of the production of nuclear materials and the shipment of radioactive waste from the facility.[5]
OPAL was opened on 20 April 2007 by then Australian Prime Minister John Howard[6] and is the replacement for the HIFAR reactor. ANSTO received an operating licence from the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) in July 2006, allowing commencement of hot commissioning, where fuel is first loaded into the reactor core. OPAL went critical for the first time on the evening of 12 August 2006 and reached full power for the first time on the morning of 3 November 2006.[7]
The reactor core consists of 16 low-enriched plate-type fuel assemblies and is located under 13 metres (43 ft) of water in an open pool. Light water (normal H2O) is used as the coolant and moderator while heavy water (D2O) is used as the neutron reflector. The purpose of the neutron reflector is to improve neutron economy in the reactor, and hence to increase the maximum neutron flux.
OPAL is the centrepiece of the facilities at ANSTO, providing radiopharmaceutical and radioisotope production, irradiation services (including neutron transmutation doping of silicon), neutron activation analysis and neutron beam research. OPAL is able to produce four times as many radioisotopes for nuclear medicine treatments as the old HIFAR reactor, and a wider array of radioisotopes for the treatment of disease. The modern design includes a cold neutron source (CNS).[2]
The OPAL reactor already has received seven awards in Australia.[8]
The Bragg InstituteatANSTO hosts OPAL's neutron scattering facility. It is now running as a user facility serving the scientific community in Australia and around the world. New funding was received in 2009 in order to install further competitive instruments and beamlines. The actual facility comprises the following instruments:
ECHIDNA is the name of the high-resolution neutron powder diffractometer. The instrument serves to determine the crystalline structures of materials using neutron radiation analogous to X-ray techniques. It is named after the Australian monotreme echidna, as the spiny peaks of the instrument looks like an echidna.
It operates with thermal neutrons. One of the main features is the array of 128 collimators and position sensitive detectors for rapid data acquisition. ECHIDNA allows for structure determinations, texture measurements and reciprocal space mapping of single crystals in most different sample environments serving the physics, chemistry, materials, minerals and earth-science communities. ECHIDNA is part of the Bragg Institute's park of neutron scattering instruments.[9]
PLATYPUS is a time-of-flight reflectometer built on the cold neutron source. The instrument serves to determine the structure of interfaces using highly collimated neutron beams. These beams are shone on to the surface at low angles (typically less than 2 degrees) and the intensity of the reflected radiation is measured as a function of angle of incidence.
It operates using cold neutrons with a wavelength band of 0.2–2.0 nm. Although up to three different angles of incidence are required for each reflectivity curve, the time-of-flight nature means that timescales of kinetic processes are accessible. By analysing the reflected signal one builds a picture of the chemical structure of the interface. This instrument can be used for examining biomembranes, lipid bilayers, magnetism, adsorbed surfactant layers, etc.
It is named after Ornithorhynchus anatinus, the semi-aquatic monotreme mammal native to Australia.
WOMBAT is a high-intensity neutron powder diffractometer. The instrument serves to determine the crystalline structures of materials using neutron radiation analogous to X-ray techniques. It is named after the wombat, a marsupial indigenous to Australia.
It will operate with thermal neutrons. It has been designed for highest flux and data acquisition speed in order to deliver time resolved diffraction patterns in a fraction of a second. Wombat will concentrate on in-situ studies and time critical investigations, such as structure determinations, texture measurements and reciprocal space mapping of single crystals in most different sample environments serving the physics, chemistry, materials, minerals and earth-science communities.
KOWARI is a neutron residual stress diffractometer. Strain scanning using thermal neutrons is a powder diffraction technique in a polycrystalline block of material probing the change of atomic spacing due to internal or external stress. It is named after the kowari, an Australian marsupial.
It provides a diagnostic non-destructive tool to optimise e.g. post weld heat treatment (PWHT, similar to tempering) of welded structures. Tensile stresses for example drive crack growth in engineering components and compressive stresses inhibit crack growth (for example cold-expanded holes subject to fatigue cycling). Life extension strategies have high economic impact and strain scanning provides the stresses needed to calculate remaining life as well as the means to monitor the condition of components since it is non-destructive. One of the main features is the sample table that will allow examination of large engineering components while orienting and positioning them very accurately.[citation needed]
During the initial testing and commissioning stages each equipment and system was tested isolated and then in an integrated manner. First tests were carried out without nuclear fuel loaded into the core, and then a careful plan was followed for loading nuclear fuel in the reactor core and reaching a nuclear chain for the first time. Successive increasing power steps were followed to get the reactor to run at full power. Once commissioning was completed, the Australian Nuclear regulatory Body (ARPANSA) issued a licence that authorise its operation at full power. During the first operation cycles a typical teething period of a first of a kind design followed.[17][18] The reactor has shown to be a reliable supplier of radiopharmaceuticals, while also serving as a neutron source to conduct material research activities using the several instruments.[19][20]
Since commissioned the reactor has been running with a very high availability, during the term 2012-13 it operated 265 days at full power (including an extended routine maintenance period), during 2013-14 for 294 days at full power, and during 2014-15 it operated 307 days at full power.
As at September 2016 it has accumulated a total of 2200 equivalent Full Power Days. Each 30 days operating cycle more than 150 batches of Silicon are irradiated, Mo99 is produced on a regular basis for the nuclear medicine market. OPAL has delivered 4 million doses. Regarding research with neutrons the Australian Centre for Neutron Scattering (formerly Bragg Institute) features more than 120 scientists and 13 neutron beam operational instruments, and has produced more than 600 scientific research papers using the neutrons coming from OPAL core.[citation needed]
34°03′05″S 150°58′44″E / 34.051339°S 150.978799°E / -34.051339; 150.978799