Lf / OC)
JOINT TASK FORCE SEVEN
Be
TASK GROUP 7,3
APO 187, c/o Postmster
seal
San Francisco,
California
From:
Commander, Task Group 7.3
Via:
(1) Commander Joint Task Force SEVEN.
(2) Commander in Chief, U.S. Pacific Fleet
Tos
FF3/7.3/32:mf
J15-9
Ser: 00666
410482
Chief of Naval Operations
Subj:
Radioactive Contamination of Ships and Radiological Exposure of Personnel
Ref:
(a)CTG 723Conf dispatch 130733Z of March 1954
Encl:
(1) Diagram indicating positions of TG 7.3 ships from H hour until about.
of Task Group 7.3 due'to BRAVO, the First Nuclear Explosion of CASTLE
7
'
0815, 1 March 195k
(2) Tabulation of average topside radioactive intensities of Task Group:2.3
ships, at various times following BRAVO,
(3) Tabulation of accumulated radiological exposures of Task Group 7.3
personnel by ships and units. .-
(4) BATROKO (CVE 115
secret serial 0010 of 11 March 195he,
1. On 1 March 1954, at O645M, the first nuclear explosion (BRAVO) of operation”
CASTLE was detonated, Prior to the detonation, ships of Task Group.7,3 had been..
deployed at’ sea generally in the. southeast quadrant from ground zero as indicated’ °
in enclosure (1), This disposition and its “location were based on four principat
factors, {a) the latest CJTF SEVEN radex, (b) the requirements of thé Commander.’
Scientific Task Group (CTG 7,1) tht. ESTES (AGC 12) andCURTISS (AV &) be positian
ed about 12 miles from ENYU Island for reliable UHF communications and Ra
purposés, (c) the requirement that ships be disposed at safe distanges (at: Yeast”
30 miles} ‘from ground zero:to avoid harmful heat, and blast effectscane:{a)’‘the,
requirement of reasonable gonentration for communications and /¢ontxrolpurposes. .
Prior to the detonation and because later winddata began to indteatesan|easterly -
component, -some ofthe ‘smaller and slower units were directed :to move: to:the southy
CLASSIFICATION
CANCELLED
but the larger ships were retained inthe localities indicated in view ofthe’
foregoing requirements (b) and (d) and the expressed desire of theJIF ‘Commander
that they not be moved,’ Because. of the additional requirements for earlyheli-~
copter survey trips and‘the early ‘dispatch by’ helicopter of an emergency airfield
crew for the airfield. én ENINMAN Island, the large ships were retained generally
in their pre-shot positions after.the detonation untilabout O800M, when sudden_
and rapidly increasing radioactive fallout was detected on some ships. At this
time, all ships wereordered to take all possible radiologicaldefense damage-
control measures, Ancluding the employment of washdow systems,.and to proceed to
the south at best speed,
2.
Commencing about O8O0OM, highly radioactive, visible, “white particles, about, the
size of pinheads, began to "fall on BAIROKO, PHILIP, ESTES and CURTISS,
time BAIROKO was about 31 miles from ground zero.
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