The Comprehensive Nuclear-Test-Ban Treaty – Australia's Contributions Over Decades

The age of nuclear weapons began with a nuclear test explosion, and the twentieth century saw over 2000 more – symbols of the Cold War and the growth of nuclear arsenals. While nuclear weapons are still with us, only one country, the Democratic People's Republic of Korea (DPRK), is known to have carried out explosive nuclear tests in the last twenty years. The Comprehensive Nuclear-Test-Ban Treaty (CTBT) has been important to this shift in global norms – even though it is not yet in legal force. Australia's history and geography have made it a strong and active supporter of efforts to achieve a ban on nuclear testing, and forged a determination to continue that support through the difficult strategic environment emerging in this twenty-first century.

From 1952 to 1963, Australia hosted a number of nuclear weapon development tests by the United Kingdom. Although these were supported by the Australian Government at the time, this part of Australian history has come to be viewed more negatively. Reaction to nuclear testing in the South Pacific in the 1980s strengthened this trend further. This, together with broader concerns about the proliferation of nuclear weapons, has firmly shaped public opinion and government policy in Australia on nuclear weapons testing over several decades.

Since the 1980s, Australia has advocated at a high political level for efforts to negotiate a multilateral and comprehensive ban on nuclear weapons testing, and to put that ban into effect. Australia was instrumental in pushing for a comprehensive ban on nuclear tests and was a key force behind the drafting of the final text for the CTBT and for making possible its adoption by the United Nations General Assembly in 1996. Australia signed the Treaty on the day it opened for signature on 24 September 1996 and ratified it on 9 July 1998. In the years since, Australia has continued to support the Treaty and the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), co-chairing the Friends of the CTBT Ministerial process and leading the annual CTBT resolution in the United Nations General Assembly. Australia's diplomats and experts continue to work directly with many countries, especially those in our region, to encourage further signatures and ratifications of the CTBT.

Australia's history and geography has also influenced its role in relation to nuclear test monitoring and the CTBT. Seismic arrays near Alice Springs and Tennant Creek in the Northern Territory were built in the 1950s and 1960s to support allied monitoring of nuclear weapons testing. Those stations continue to operate today, and have now been incorporated in the CTBT's International Monitoring System (IMS). They are widely regarded as amongst the most useful in the IMS for very-long-distance detection of seismic events.

A Group of Scientific Experts (GSE) established in 1976 by the Conference of the Committee on Disarmament (precursor to the present Conference on Disarmament) began the important work that enabled negotiation of the CTBT. Australian technical experts contributed actively to the GSE, for example by coordinating the first large-scale test of the exchange and analysis of seismic data in 1984.

A further 21 Australian-hosted facilities have been added to the IMS since the 1990s, covering each of the technologies (seismic, infrasound, radionuclide and hydroacoustic) for detecting evidence of a possible nuclear test explosion. Australian IMS stations stretch from latitude 12° to 68° South and from longitude 63° to 159° East and monitor a significant part of the globe. The last of Australia's monitoring facilities was completed in 2018 – an infrasound monitoring array at Davis Station in Australian Antarctic Territory.

ASNO took on the role of Australia's National Authority for the CTBT in 1998 and has overseen the completion of Australia's IMS stations, working together with colleagues from Geoscience Australia (GA), the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), the Australian National University and, of course, from the CTBTO in Vienna.

Experts from ASNO and various Australian agencies have played leading roles in the broader technical work of the CTBTO, for example to establish and test its International Data Centre, and to assist the development of a capability to conduct on-site inspections to verify compliance after the Treaty has entered into force.

In the 1980s, a program was established to analyse data from seismic stations to identify events of concern and advise the Australian Government where it appeared that a nuclear test might have occurred. This program continues to be operated by GA and has been supplemented by ARPANSA's expert analysis of radionuclide detections. These capabilities enable Australia to draw on the IMS to detect and analyse any further nuclear testing, for example by the DPRK, but also provide good assurance that no other country may return to explosive nuclear testing without detection.

Warramanga IMS facility (Credit: The Australian National University).