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The U.S. and Subcritical Nuclear Testing

As expressed in its Preamble, preventing further nuclear weapons development and advancing the cause of nuclear disarmament is the clear aim of the Comprehensive Test Ban Treaty (CTBT). The US, Russia, and other Nuclear Weapons States are continuing nuclear weapons research and development using stockpile stewardship technologies including "subcritical" explosive underground tests involving plutonium. Subcritical nuclear tests are not considered full nuclear tests because they do not achieve a self-sustained chain reaction. However, the tests do involve high explosives blown up with fissile material (usually plutonium). Sophisticated equipment record data from the test that is later fed into computers. Although not full nuclear weapons tests, subcritical testing violates the heart and spirit of the CTBT. The US and Russia claim that subcritical tests are needed to maintain the safety and reliability of their nuclear stockpiles.

9/24/96 US President Clinton signs the Comprehensive Test Ban Treaty.

10/8/96 The US Department of Energy announces it will conduct subcritical tests at Nevada Test Site.


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See Also
Protocol to the Treaty Between the United States of America and Union of Soviet Socialist Republics on the Limitation of UndergroundNuclear Weapon Tests (13 I.L.M. 906, entered into force Dec. 11, 1990)
Atomic Energy Commission Meeting 1377, May 28, 1958


4/4/97 US Secretary of Energy Peña announces US plans to conduct subcritical tests.

Timeline of US Subcritical Nuclear Tests

Test Name

Conducted By
7/2/97 Rebound LANL
9/18/97 Holog LLNL
3/25/98 Stagecoach LANL
9/26/98 Bagpipe LLNL
12/11/98 Cimarron LANL
2/9/99 Clarinet LLNL
9/30/99 Oboe 1 LLNL
11/9/99 Oboe 2 LLNL
2/3/00 Oboe 3 LLNL
3/22/00 Thoroughbred LANL
4/6/00 Oboe 4 LLNL
8/18/00 Oboe 5 LLNL
12/14/00 Oboe 6 LLNL
9/26/01 Oboe 8 LLNL
12/13/01 Oboe 7 LLNL
2/14/02 Vito LANL and UK (under the terms of the 1958 Mutual Defense Agreement)
6/7/02 Oboe 9  
8/29/02 Mario  
9/26/02 Rocco  
9/19/03 Piano  
5/25/04 Armando  
2/23/06 Krakatau  
8/30/06 Unicorn  
9/15/10 Bacchus  
12/1/10 Barolo A  
2/2/11 Barolo B  
12/5/12 Pollux LANL and Sandia
LANL: Los Alamos National Laboratory LLNL: Lawrence Livermore National Laboratory