Announced United States Nuclear Tests
July 1945 Through December 1992
This documentlists chronologically and alphabetically by event nameall nuclear tests conducted and announced by the United States from
July 1945 through December 1992, with the exception of the GMX experiments. The 24 GMX experiments, conducted at the Nevada Test
Site (NTS) between December 1954 and February 1956, were “equation-of-state” physics studies that used small chemical explosives and
small quantities of plutonium. Several tests conducted during Operation Dominic involved missile launches from Johnston Atoll. Several of
these missile launches were aborted, resulting in the destruction of the missile and nuclear device either on the pad orin the air.
On August 5, 1963, the United States and the Soviet Union signed the Limited Test Ban Treaty which effectively banned testing of nuclear
weaponsin the atmosphere. Ail United States nuclear tests conducted prior to that date have been announced andarelisted in this document.
Some tests conducted underground since the signing of the Treaty and designed to be contained completely have not been announced.
Information concerning these events is classified. Occasionally, the name and detonation date of an unannounced test is deciassified which
permits its listing in subsequent revisions to this document.
Data on United States tests were obtained from, and verified by, the Department of Energy’s three weapons laboratories -- Los Alamos
National Laboratory, Los Alamos, New Mexico; Lawrence Livermore National Laboratory, Livermore, California; and Sandia National
Laboratories, Albuquerque, New Mexico. Additionally, data were obtained from public announcements issued by the Atomic Energy
Commission and its successors, the Energy Research and Development Administration, and the Department of Energy, respectively.
Test Dates
Time and date for all events listed in this document were converted from local time to Greenwich Civil Time {GCT). The event date listed is
the GCT date for the event.
Series
Eachseries of tests is given a name such as Operation Crossroads. United States nuclear tests were conducted on an intermittent basis from
June 1946 to October 1958.