The Nuclear Testing Tally | Arms Control Association (2024)

United States
(1,030)
First test:
July 16, 1945.
Last test:
Sept. 23, 1992.
Signed CTBT:
Sept. 24, 1996.

USSR/Russia
(715 tests)
First test:
Aug. 29, 1949.
Last test:
Oct. 24, 1990.
Deposited CTBT Ratification:
June 30, 2000.

United Kingdom
(45 tests)
First test:
Oct. 3, 1952.
Last test:
Nov. 26, 1991.
Signed CTBT:
Sept. 24, 1996.
Deposited CTBT Ratification:
Apr. 6, 1998.

France
(210 tests)
First test:
Feb. 13, 1960.
Last test:
Jan. 27, 1996.
Signed CTBT:
Sept. 24, 1996.
Deposited CTBT Ratification:
Apr. 6, 1998.

China
(45 tests)
First test:
Oct. 16, 1964.
Last test:
July 29, 1996.
Signed CTBT:
Sept. 24, 1996.

India
(3 tests²)
First test:
May 18, 1974.
Last test:
May 13, 1998.
Not a CTBT signatory.

Pakistan
(2 tests³)
First test:
May 28, 1998.
Last test:
May 30, 1998.
Not a CTBT signatory.

North Korea
(6 tests)
First test:
Oct. 9, 2006.
Last test:
Sept. 3, 2017.
Not a CTBT signatory.

NOTES

1. The total number and yearly listing of U.S. nuclear test explosions listed in this fact sheet are based on the figures published in United States Nuclear Tests: July 1945 through September 1992 DOE/NV-209 (Rev. 14), December 1994. The Department of Energy has since pubished two revisions of the pubication that slightly revise these numbers and reassign the purposes originally described for certain nuclear test explosions.

2. This "Nuclear Testing Tally" includes nuclear tests announced or reported by governments and/or intergovernmental organizations. As such, it does not take into account the "Vela Incident" of 1979 because it has not yet officially been determined by any government or intergovernmental organization to have been a nuclear test explosion. However, there is strong evidence and analysis by independent experts that suggests it was an atmospheric nuclear weapon test explosion.

3. In accordance with the definition of a nuclear test contained in the 1974 Threshold Test Ban Treaty and to allow accurate comparison with other countries' figures, India's three simultaneous nuclear explosions on May 11 are counted as only one nuclear test, as are the two explosions on May 13. Likewise, Pakistan's five simultaneous explosions on May 28 are counted as a single test.

4. In the article "Radionuclide Evidence for Low-Yield Nuclear Testing in North Korea in April/May 2010," Lars-Erik De Geer argued that the xexon and barium isotope concentrations in air currents from North Korea in April and May of 2010 were consistent with two low-yield nuclear tests. However, this theory was largely debunked when the Earth Institute at Columbia University measured seismology records and determined that no well-coupled explosion larger than one ton could have occurred during that timeframe. According to the report, such a low yield explosion would have been incapable of advancing the North Korean's technical understanding of a nuclear weapon explosion.