Circa Date

May 1954

Description

This report by the Armed Forces Special Weapons Project was one of the earliest comprehensive studies of Castle Bravo. Although the test took place on a coral reef, the report said it constituted a “unique opportunity to gain at least partial documentation of fall-out radiation effects from a large yield weapon burst under conditions at least approximating a land-surface detonation.” One of the report’s major findings was that the “land surface detonation of a 15 megaton yield weapon can be expected to deposit radioactive fall-out over an area of the order of 5,000 square miles or more in such intensities as to be hazardous to human life.” Without the taking of “passive defense measures, fatalities in that area would be 100 percent.” Thus, survival would depend on taking shelter and evacuating contaminated areas after ten days when it had become safer. This made radiation danger “a primary anti-personnel effect”—one of the panoply of weapons effects that defense planners could take into account when assessing the destructiveness of high yield, multi-megaton H-bombs.

Source

DOE OpenNet

Document published in following posting(s):

Castle BRAVO at 70: The Worst Nuclear Test in U.S. History

Feb 29, 2024

Armed Forces Special Weapons Project, Weapons Effects Division, “Radioactive Fall-out Hazards from Surface Bursts of Very High Yield Nuclear Weapons,” by D.C Borg et al., Technical Analysis Report, AFSWP No. 507, May 1954, Excised copy (under declassification review), No classification marking