The 'Trinity' test on 16 July 1945 at 0.016 seconds after detonation.
It was the first-ever nuclear explosion and the first of 1,032
U.S. nuclear tests.

The Soviet Union carried out 715 nuclear tests,
starting with the ‘RDS-1’ test on 29 August 1949
in Semipalatinsk in today’s Kazakhstan.

‘Hurricane’ was the first of 45 UK nuclear tests,
conducted on 3 October 1952 at the Montebello
Islands in Western Australia.

The first of 210 nuclear tests by France was carried
out on 13 February 1960 in the Sahara Desert of Algeria.

Monument for victims of nuclear testing in Algeria (source: AVEN)

China conducted its first of 45 nuclear tests
on 16 October 1964 at the Lop Nur test site.

India conducted its first nuclear explosion of a total
of three on 18 May 1974 in the Pokhran desert.

Pakistan conducted its first of two nuclear tests on 28 May 1998.

The Democratic People's Republic of Korea (DPRK)
conducted one test in 2006, 2009 and 2013 each.

International Day against Nuclear Tests

The first Soviet nuclear test was conducted on 29 August 1949.

In December 2009, the United Nations General Assembly unanimously declared 29 August as the International Day against Nuclear Tests (see also UN Website and message from UN Secretary-General Ban Ki-moon). This day was proposed by Kazakhstan as it marks both the closure of the former Soviet Semipalatinsk Test Site in 1991 in modern-day Kazakhstan and the date of the first Soviet nuclear test conducted there in 1949.

Levels of radiocarbon (C14) in the atmosphere 1945 - 2000. Image credit: Hokanomono.

According to the resolution establishing it, the International Day against Nuclear Tests aims to prevent more of the “devastating and harmful effects on the lives and health of people and the environment” caused by nuclear testing. Over 2,000 nuclear tests have been conducted since the very first nuclear explosion, the Trinity test on 16 July 1945 in New Mexico, United States. Together, the fallout from these tests dwarfed the amount of radioactivity released into the environment from any nuclear accident.

Servicemen often played the role of guinea pigs in the first decades of nuclear testing.

The servicemen involved and people living close to the test sites often paid with their health, some even with their lives; see chapter effects of nuclear testing. Some of the world’s over 60 nuclear test sites (see interactive map) continue to be contaminated.

Click for graphic yield comparison (not included: the 50 megaton Tsar Bomba).

Nuclear testing also poisoned the political environment, leading to an arms race with ever more destructive weapons. The 1961 Soviet Tsar Bomba had an explosive power of around 4,000 Hiroshima bombs detonated simultaneously.

Today is a reminder that the world is united against the devastating effects of nuclear testing on the lives of people and the environment. It’s a reminder that the Comprehensive Nuclear-Test-Ban Treaty (CTBT) must enter into force. The CTBT not only closes the door on nuclear testing -- it is a critical step towards the elimination of nuclear weapons.CTBTO Executive Secretary Lassina Zerbo

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is the international instrument to end all nuclear testing in a verifiable way. Nuclear testing has essentially screeched to a halt with the adoption of the CTBT in 1996, which forged an international zero-tolerance stance against nuclear testing: The handful of nuclear tests conducted after 1996 (by India, Pakistan and the Democratic People’s Republic of North Korea - DPRK) received universal condemnation and unanimously adopted UN Security Council sanctions.


Currently 183 States have signed the Treaty and 159 have ratified it (see interactive map). However for the CTBT to enter into force, eight States - from a list of 44 defined as nuclear technology holders - have yet to ratify to meet the Treaty’s stringent entry into force requirement: China, DPRK, Egypt, India, Iran, Israel, Pakistan and the United States.

On 27 September 2013, Foreign Ministers from CTBT Member States will gather at UN headquarters in New York for a conference, called the Article XIV Conference, to promote the CTBT's entry into force.

The strong and unified response to the nuclear test announced in February by the Democratic People’s Republic of Korea demonstrated the international community’s commitment to uphold the global norm against nuclear tests. The Comprehensive Nuclear Test-Ban Treaty is a cornerstone of our work. I once again urge all States to sign and ratify the CTBT – especially the eight remaining States whose ratifications are necessary for the Treaty to enter into force.Secretary-General Ban Ki-moon’s Message for the International Day against Nuclear Tests 2013

2013 Events


To commemorate the International Day against Nuclear Tests in 2013, the United Nations General Assembly held a special meeting on 5 September 2013, followed by a panel discussion, in which CTBTO Executive Secretary Lassina Zerbo participated - see statement.

On 4 September 2013, the Permanent Mission of Kazakhstan to the United Nations in New York organized an exhibition under the title "Peace Now: Abolish Nuclear Tests and Weapons".

See United Nation website or the flyer (image) for more information.