ACA DIO
1 December 1981
Fact
dina
Defense Nuclear Agency
Public Affairs Office
S h eet
Washington, D.C. 20305
Operation CASTLE
CASTLE was a six-detonation nuclear weapon test series {see table) held at the Atomic
Energy Commission's (AEC) Pacific Proving Ground (PPG) in Spring 1954.
The PPG consisted
principally of Enewetak* and Bikini atolls in the northwestern Marshall Islands in the Central
Pacific Ocean.
Assigned
Date
Name
Location
Magnitude
1 March
BRAVO
Bikini; sandspit off Nam Island
27 March
ROMEO
Bikini; barge in BRAVO crater
7 April
KOON
Bikini; surface of Eneman Island
26 April
UNION
Bikini; barge in lagoon off Iroij Island
5 May
YANKEE
Bikini; barge in UNION crater
14 May
NECTAR
Enewetak; barge in MIKE crater
15 MT
.
11 MT
.
110 KTa
6.9 MT
13.5 MT
1.69 MT
Notes:
40ne kiloton equals the approximate energy release of the explosion of Ofie
thousand ‘tons of TNT; one megaton equals the approximate energy release of the
explosion of one million tons of TNT.
b10.4 MT IVY series detonation in 1952.
HISTORICAL BACKGROUND
The CASTLE series was held to test large-yield thermonuclear, or hydrogen, devices. Work
on this class of devices had progressed through the GREENHOUSE, GEORGE experimental shot in
1951 and the
*
IVY, MIKE
shot of 1952.
The spelling of Marshall
MIKE
was the first device
that generated
substantial
Island place names has changed in recent years in order to more
accurately render the sounds of the Marshall Island names using English spelling.
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