Meant to squeeze all possible testing into the time before Eisenhower's test ban started on 30 October 1958. Planned as "Operation Millrace", changed to HT II when a science panel recommended to "stop testing after the Hardtack series."
The last test series, cut off by the adoption of the Comprehensive Test Ban Treaty.
1945-Jul-16 to 1992-Sep-23
0 to 15,000
Total country yield is 36.3% of all nuclear testing.
Summary table notes:
^Includes all tests with potential for nuclear fission or fusion explosion, including combat use, singleton tests, salvo tests, zero yield fails, safety experiments, and bombs incapacitated by accidents but still intended to be fired. It does not include hydronuclear and subcritical tests, and misfires of a device which was subsequently fired successfully.
^Number of tests which would have been in violation of the Partial Test Ban Treaty of 1963, such as atmospheric, space or underwater tests. Some "peaceful use" cratering tests which should have been violations were protested, and later quietly dropped.
^"Small" refers to a value greater than zero but less than 0.5 kt.
^Some yields are described like "< 20 kt"; such are scored at one half of the numeric amount, i.e., yield of 10k in this example. "Unknown yield" adds nothing to the total.
^United States Nuclear Tests: July 1945 through September 1992 (DOE/NV-209 REV15). Las Vegas, NV: Department of Energy, Nevada Operations Office. 2000-12-01. Retrieved 2013-12-18. Discrepancies with the table include 24 tests actually carried out by the United Kingdom at the NTS; Fat Man and Little Boy; four aborted tests in Operation Fishbowl; one test, Anvil/Peninsula, that jammed during lowering in its shaft and was abandoned; and five salvo tests listed as two enumerated tests each because they were treated that way when eventually described to the public, rather than standing on the treaty definition of a salvo test (see Introduction - Caveat).