FACT SHEET
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.
Date
Assigned
Name
Location
1 March
BRAVO
Bikini; sandspit off Nam Island
15 mT?
27 March
ROMEO
Bikini; barge in BRAVO crater
11 MT
7 April
KOON
Bikini; surface of Eneman Island
110 KT
26 April
UNION
Bikini; barge in lagoon off Iroij Island
6.9 MT
5 May
YANKEE
Bikini; barge in UNION crater
14 May
NECTAR
Enewetak; barge in MIKED crater
Magnitude
13.5 MT
1.69 MT
Notes:
4one kiloton equals the approximate energy release of the explosion of
one thousand tons of TNT; one megaton equals the approximate energy
release of the explosion of one million tons of TNT.
b 10.4-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.
MIKE was the first device that generated a substantial explosive
energy from the fusion, or joining, of hydrogen atoms.
These explosive
* The spelling of Marshall Island place names has changed in recent years
in order to more accurately render the sounds of the Marshall Island
names using English spelling.
(