U.S. Nuclear Testing Program in the Marshall Islands

During the period from June 30, 1946, to August 18, 1958, the United States conducted 67 nuclear tests in the Marshall Islands, all of which were considered atmospheric. The most powerful of those tests was the "Bravo" shot, a 15 megaton device detonated on March 1, 1954, at Bikini atoll. That test alone was equivalent to 1,000 Hiroshima bombs.

While the Bravo test is well known, it should be acknowledged that 17 other tests in the Marshall Islands were in the megaton range and the total yield of the 67 tests was 108 megatons, the equivalent of more than 7,000 Hiroshima bombs.

For the sake of comparison, it may be noted that from 1945 to 1988, the U.S. conducted a total of 930 known nuclear tests with a combined yield estimated to be 174 megatons. Approximately 137 megatons of that total was detonated in the atmosphere. In other words, while the number of tests conducted in the Marshall Islands represents only about 14% of all U.S. tests, the yield of the tests in the Marshalls comprised nearly 80% of the atmospheric total detonated by the U.S.

Under Article IV of the Section 177 Agreement, The Governments of the United States and the Marshall Islands agreed to the establishment of a Claims Tribunal which would have jurisdiction "to render final determinations of all claims past, present and future, of the Government, citizens and nationals of the Marshall Islands which are based on, arise out of, or are in any way related to the Nuclear Testing Program, and disputes arising from distributions made under Article II and III of this agreement."

Notes:

(1) Experimental thermonuclear device, produced a crater 6,240 feet in diameter and 164 feet deep. Device itself weighed 164,000 lbs.
(2) Largest nuclear test explosion conducted by the United States, produced a crater 6,000 feet in diameter and 240 feet deep. Expected yield 6 megatons (presumed range 4 to 8 megatons). Cloud top 114,000 feet.
(3) Balloon detonation at 12°37' N, 169°01' E, approximately 85 miles northeast of Enewetak.
(4) "Safety experiment."

Addendum to "Compilation of Local Fallout Data From Test Detonations 1945-1962 Extracted From DASA 1251" Volume II - Oceanic U.S. Tests, 1 May 1979, prepared by General Electric Company-TEMPO under contract to the Defense Nuclear Agency.

"Nuclear Weapons Databook Working Papers - Known U.S. Nuclear Tests" January 1989, published by Natural Resources Defense Council.

U.S. Department of Energy "List of Declassified Yields of Tests Conducted in the Pacific Prior to 1958-1961 Moratorium, December 1993."