ARPANSA - Australian Radiation Protection and Nuclear Safety Agency

What is the Comprehensive Nuclear-Test-Ban Treaty?

A Comprehensive Nuclear-Test-Ban Treaty (CTBT) to ban all nuclear explosion tests was opened for signature in New York on 24th September 1996. Australia signed the Treaty on the same day and ratified it on 9th July 1998. As of June 2007, 177 countries have signed and 138 have ratified. To see the latest country to sign or ratify and to find more information on the CTBT Organisation visit their website at http://www.ctbto.org.

How can nuclear tests be detected?

An International Monitoring System (IMS) is being constructed to monitor compliance with the Treaty. By analysing, integrating and comparing data from the IMS, the time, location and nature of a possible nuclear event can be determined. The network consists of 321 monitoring facilities and 16 radionuclide laboratories that monitor the earth for evidence of nuclear explosions in all environments. These monitoring facilities use a variety of methods to detect evidence of nuclear testing. Seismic, hydroacoustic and infrasound stations are employed to monitor the underground, underwater and atmosphere environments, respectively. The fourth technology detects radiation from atmospheric sampling.

Monitoring Technologies

Seismic (50 Primary & 120 Auxiliary)

Seismic monitors detect vibrations in the earth’s crust. The principal use of the seismic data in the verification system is to locate seismic events and to distinguish between an underground nuclear explosion and the numerous earthquakes that occur around the globe.

Hydroacoustic (11 stations)

Hydroacoustic monitoring detects acoustic waves produced by natural and artificial phenomena in the oceans. The data from the hydroacoustic stations are used in the verification system to distinguish between underwater explosions and other phenomena, such as sub-sea volcanoes and earthquakes, which also propagate acoustic energy into the oceans.

Infrasound (60 stations)

The infrasound network uses microbarographs (acoustic pressure sensors) to detect very low-frequency sound waves in the atmosphere produced by natural and artificial events. The data collected is used to distinguish between atmospheric explosions and natural phenomena such as meteorites, explosive volcanoes, meteorological events and artificial phenomena such as re-entering space debris, rocket launches and supersonic aircraft.

Radionuclide (80 stations)

The 80 radionuclide stations can detect radioactive debris from atmospheric explosions or vented by underground or underwater nuclear explosions. The presence of specific radionuclides provides unambiguous evidence of a nuclear explosion. See below for more on how these stations work.

Radionuclide Laboratories (16 stations)

The 16 Radionuclide Laboratories are used to verify samples that are suspected of containing radionuclide materials that may have been produced by a nuclear explosion.

What is ARPANSA's involvement with the Treaty?

ARPANSA is responsible for carrying out Australia's radionuclide monitoring obligations to the Comprehensive Nuclear-Test-Ban Treaty. ARPANSA is responsible for the installation, implementation and operation of seven stations within Australia and its Territories. ARPANSA operates and maintains an eighth station on behalf of Papua New Guinea.

What are the locations of the Australian monitoring stations?

Australia hosts all four technologies totalling 21 facilities within Australia and its Territories.

Location	State or Territory	Type	Treaty Code	Coordinates
				Lat	Lon
Charters Towers	Queensland	Auxiliary Seismic Station	AS004	-20.1	146.3
Fitzroy Crossing	Western Australia	Auxiliary Seismic Station	AS005	-18.1	125.6
Narrogin	Western Australia	Auxiliary Seismic Station	AS006	-32.9	117.2
Cape Leeuwin	Western Australia	Hydroacoustic Station	HA01	-34.4	115.1
Davis Base	Antarctica	Infrasound Station	IS03	-68.4	77.6
Narrogin	Western Australia	Infrasound Station	IS04	-32.9	117.2
Hobart	Tasmania	Infrasound Station	IS05	-42.1	147.2
Cocos Islands	Western Australia	Infrasound Station	IS06	-12.3	97
Warramunga	Northern Territory	Infrasound Station	IS07	-19.9	134.3
Warramunga	Northern Territory	Primary Seismic Station	PS02	-19.9	134.3
Alice Springs	Northern Territory	Primary Seismic Station	PS03	-23.7	133.9
Stephens Creek	South Australia	Primary Seismic Station	PS04	-31.9	141.6
Mawson	Antarctica	Primary Seismic Station	PS05	-67.6	62.9
ARPANSA, Melbourne	Victoria	Radionuclide Laboratory	RL02	-37.5	144.6
Melbourne	Victoria	Radionuclide Station	RN04	-37.5	144.6
Mawson,	Antarctica	Radionuclide Station	RN05	-67.6	62.5
Townsville, QLD	Queensland	Radionuclide Station	RN06	-19.2	146.8
Macquarie Island	Tasmania	Radionuclide Station	RN07	-54	159
Cocos Islands	Western Australia	Radionuclide Station	RN08	-12	97
Darwin	Northern Territory	Radionuclide Station	RN09	-12.4	130.7
Perth	Western Australia	Radionuclide Station	RN10	-31.9	116

A Typical Radionuclide Monitoring Station Process

The Radionuclide Monitoring process involves collecting particulate matter from the air onto a piece of filter material in a high volume air sampler for ~24 hours.		After this time the filter is taken from the air sampler, compressed into a disk.
Finally, the filter sample is placed on a gamma detector for ~24 hours to be analysed.		The disk is then placed in a chamber to allow natural radionuclides to decay for ~24 hours.
A computer monitors the workflow and collects data.		The data relating to the sampling conditions and radionuclides measured is then forwarded by satellite to the International Data Centre in Vienna where it is compiled and released to Countries participating in the Treaty.

 

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